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Afzal F, Spieker K, Hurck P, Abt S, Achenbach P, Adlarson P, Ahmed Z, Akondi CS, Annand JRM, Arends HJ, Bashkanov M, Beck R, Biroth M, Borisov N, Braghieri A, Briscoe WJ, Cividini F, Collicott C, Costanza S, Denig A, Dieterle M, Downie EJ, Drexler P, Fegan S, Gardner S, Ghosal D, Glazier DI, Gorodnov I, Gradl W, Gurevich D, Heijkenskjöld L, Hornidge D, Huber GM, Kashevarov VL, Kay SJD, Korolija M, Krusche B, Lazarev A, Livingston K, Lutterer S, MacGregor IJD, Macrae RG, Manley DM, Martel PP, Miskimen R, Mocanu M, Mornacchi E, Mullen C, Neganov A, Neiser A, Oberle M, Ostrick M, Otte PB, Paudyal D, Pedroni P, Powell A, Reicherz G, Rostomyan T, Sfienti C, Sokhoyan V, Steffen O, Strakovsky II, Strub T, Supek I, Thiel A, Thiel M, Thomas A, Usov YA, Wagner S, Walford NK, Watts DP, Werthmüller D, Wettig J, Witthauer L, Wolfes M, Zachariou N. First Measurement Using Elliptically Polarized Photons of the Double-Polarization Observable E for γp→pπ^{0} and γp→nπ^{+}. Phys Rev Lett 2024; 132:121902. [PMID: 38579200 DOI: 10.1103/physrevlett.132.121902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 04/07/2024]
Abstract
We report the measurement of the helicity asymmetry E for the pπ^{0} and nπ^{+} final states using, for the first time, an elliptically polarized photon beam in combination with a longitudinally polarized target at the Crystal Ball experiment at MAMI. The results agree very well with data that were taken with a circularly polarized photon beam, showing that it is possible to simultaneously measure polarization observables that require linearly (e.g., G) and circularly polarized photons (e.g., E) and a longitudinally polarized target. The new data cover a photon energy range 270-1400 MeV for the pπ^{0} final state (230-842 MeV for the nπ^{+} final state) and the full range of pion polar angles, θ, providing the most precise measurement of the observable E. A moment analysis gives a clear observation of the pη cusp in the pπ^{0} final state.
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Affiliation(s)
- F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - P Hurck
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - S Abt
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - P Achenbach
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P Adlarson
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Z Ahmed
- University of Regina, Regina, SK S4S0A2, Canada
| | - C S Akondi
- Kent State University, Kent, Ohio 44242, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Bashkanov
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Biroth
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Braghieri
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - F Cividini
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - C Collicott
- Department of Astronomy and Physics, Saint Mary's University, E4L1E6 Halifax, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- Dipartimento di Fisica, Università di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Dieterle
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - E J Downie
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - P Drexler
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - S Fegan
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - D Ghosal
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - I Gorodnov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - W Gradl
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Gurevich
- Institute for Nuclear Research, RU-125047 Moscow, Russia
| | - L Heijkenskjöld
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
| | - G M Huber
- University of Regina, Regina, SK S4S0A2, Canada
| | - V L Kashevarov
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S J D Kay
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - S Lutterer
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - R G Macrae
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242, USA
| | - P P Martel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - M Mocanu
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - E Mornacchi
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - C Mullen
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - A Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Neiser
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Oberle
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Paudyal
- University of Regina, Regina, SK S4S0A2, Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - A Powell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr Universität, 44780 Bochum, Germany
| | - T Rostomyan
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - C Sfienti
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - V Sokhoyan
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - O Steffen
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - T Strub
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Thiel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Wagner
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N K Walford
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - D P Watts
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - D Werthmüller
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
| | - J Wettig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - L Witthauer
- Department of Physics, University of Basel, Ch-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N Zachariou
- Department of Physics, University of York, Heslington, York, Y010 5DD, United Kingdom
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2
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Desorgher L, Stabilini A, Rostomyan T, Reggiani D, Hajdas W, Marcinkowski RM, Vozenin MC, Limoli CL, Yukihara EG, Bailat C. Dosimetry of the PIM1 Pion Beam at the Paul Scherrer Institute for Radiobiological Studies of Mice. Radiat Res 2023; 200:357-365. [PMID: 37702413 DOI: 10.1667/rade-23-00029.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 07/31/2023] [Indexed: 09/14/2023]
Abstract
Significant past work has identified unexpected risks of central nervous system (CNS) exposure to the space radiation environment, where long-lasting functional decrements have been associated with multiple ion species delivered at low doses and dose rates. As shielding is the only established intervention capable of limiting exposure to the dangerous radiation fields in space, the recent discovery that pions, emanating from regions of enhanced shielding, can contribute significantly to the total absorbed dose on a deep space mission poses additional concerns. As a prerequisite to biological studies evaluating pion dose equivalents for various CNS exposure scenarios of mice, a careful dosimetric validation study is required. Within our ultimate goal of evaluating the functional consequences of defined pion exposures to CNS functionality, we report in this article the detailed dosimetry of the PiMI pion beam line at the Paul Scherrer Institute, which was developed in support of radiobiological experiments. Beam profiles and contamination of the beam by protons, electrons, positrons and muons were characterized prior to the mice irradiations. The dose to the back and top of the mice was measured using thermoluminescent dosimeters (TLD) and optically simulated luminescence (OSL) to cross-validate the dosimetry results. Geant4 Monte Carlo simulations of radiation exposure of a mouse phantom in water by charged pions were also performed to quantify the difference between the absorbed dose from the OSL and TLD and the absorbed dose to water, using a simple model of the mouse brain. The absorbed dose measured by the OSL dosimeters and TLDs agreed within 5-10%. A 30% difference between the measured absorbed dose and the dose calculated by Geant4 in the dosimeters was obtained, probably due to the approximated Monte Carlo configuration compared to the experiment. A difference of 15-20% between the calculated absorbed dose to water at a 5 mm depth and in the passive dosimeters was obtained, suggesting the need for a correction factor of the measured dose to obtain the absorbed dose in the mouse brain. Finally, based on the comparison of the experimental data and the Monte Carlo calculations, we consider the dose measurement to be accurate to within 15-20%.
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Affiliation(s)
- L Desorgher
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Switzerland
| | - A Stabilini
- Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - T Rostomyan
- Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - D Reggiani
- Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - W Hajdas
- Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - R M Marcinkowski
- Paul Scherrer Institute (PSI), Villigen, Switzerland
- SE2S GMBH, Boppelsen ZH, Switzerland
| | - M-C Vozenin
- CHUV-Radiation-oncology Laboratory, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - C L Limoli
- Department of Radiation Oncology, University of California, Irvine, California
| | - E G Yukihara
- Paul Scherrer Institute (PSI), Villigen, Switzerland
| | - C Bailat
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Switzerland
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3
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Mornacchi E, Martel PP, Abt S, Achenbach P, Adlarson P, Afzal F, Ahmed Z, Annand JRM, Arends HJ, Bashkanov M, Beck R, Biroth M, Borisov N, Braghieri A, Briscoe WJ, Cividini F, Collicott C, Costanza S, Denig A, Dolzhikov AS, Downie EJ, Drexler P, Fegan S, Gardner S, Ghosal D, Glazier DI, Gorodnov I, Gradl W, Günther M, Gurevich D, Heijkenskjöld L, Hornidge D, Huber GM, Käser A, Kashevarov VL, Kay SJD, Korolija M, Krusche B, Lazarev A, Livingston K, Lutterer S, MacGregor IJD, Manley DM, Miskimen R, Mocanu M, Mullen C, Neganov A, Neiser A, Ostrick M, Paudyal D, Pedroni P, Powell A, Rostomyan T, Sokhoyan V, Spieker K, Steffen O, Strakovsky I, Strub T, Thiel M, Thomas A, Usov YA, Wagner S, Watts DP, Werthmüller D, Wettig J, Wolfes M, Zachariou N. Measurement of Compton Scattering at MAMI for the Extraction of the Electric and Magnetic Polarizabilities of the Proton. Phys Rev Lett 2022; 128:132503. [PMID: 35426697 DOI: 10.1103/physrevlett.128.132503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/31/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
A precise measurement of the differential cross sections dσ/dΩ and the linearly polarized photon beam asymmetry Σ_{3} for Compton scattering on the proton below pion threshold has been performed with a tagged photon beam and almost 4π detector at the Mainz Microtron. The incident photons were produced by the recently upgraded Glasgow-Mainz photon tagging facility and impinged on a cryogenic liquid hydrogen target, with the scattered photons detected in the Crystal Ball/TAPS setup. Using the highest statistics Compton scattering data ever measured on the proton along with two effective field theories (both covariant baryon and heavy-baryon) and one fixed-t dispersion relation model, constraining the fits with the Baldin sum rule, we have obtained the proton electric and magnetic polarizabilities with unprecedented precision: α_{E1}=10.99±0.16±0.47±0.17±0.34, β_{M1}=3.14±0.21±0.24±0.20±0.35; in units of 10^{-4} fm^{3} where the errors are statistical, systematic, spin polarizability dependent, and model dependent.
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Affiliation(s)
- E Mornacchi
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P P Martel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - S Abt
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - P Achenbach
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P Adlarson
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - Z Ahmed
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Bashkanov
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - M Biroth
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - N Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | | | - W J Briscoe
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - F Cividini
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Collicott
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A S Dolzhikov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - E J Downie
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - P Drexler
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Fegan
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Ghosal
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I Gorodnov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - W Gradl
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Günther
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - L Heijkenskjöld
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - A Käser
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S J D Kay
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - S Lutterer
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - M Mocanu
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - C Mullen
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - A Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Neiser
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Ostrick
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D Paudyal
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Powell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - T Rostomyan
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - V Sokhoyan
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - O Steffen
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - I Strakovsky
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - T Strub
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Thiel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Wagner
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D P Watts
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - D Werthmüller
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - J Wettig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Wolfes
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - N Zachariou
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
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4
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Mullen C, Gardner S, Glazier DI, Kay SJD, Livingston K, Strakovsky II, Workman RL, Abt S, Achenbach P, Afzal F, Ahmed Z, Akondi CS, Annand JRM, Bashkanov M, Beck R, Biroth M, Borisov NS, Braghieri A, Briscoe WJ, Cividini F, Collicott C, Costanza S, Denig A, Dieterle M, Downie EJ, Drexler P, Fegan S, Ferretti-Bondy MI, Ghosal D, Gorodnov I, Gradl W, Günther M, Gurevic G, Heijkenskjöld L, Hornidge D, Huber GM, Jermann N, Kaeser A, Korolija M, Kashevarov VL, Krusche B, Kulikov VV, Lazarev A, Lutterer S, MacGregor IJD, Manley DM, Martel PP, Martemianov MA, Meier C, Miskimen R, Mocanu M, Mornacchi E, Neganov A, Oberle M, Ostrick M, Otte P, Paudyal D, Pedroni P, Powell A, Prakhov SN, Reicherz G, Ron G, Rostomyan T, Sfienti C, Sokhoyan V, Spieker K, Steffen O, Strub T, Supek I, Thiel A, Thiel M, Thomas A, Unverzagt M, Usov YA, Wagner S, Walford NK, Watts DP, Werthmüller D, Wettig J, Witthauer L, Wolfes M, Zachariou N. Single π 0 production off neutrons bound in deuteron with linearly polarized photons. Eur Phys J A Hadron Nucl 2021; 57:205. [PMID: 34720708 PMCID: PMC8550430 DOI: 10.1140/epja/s10050-021-00521-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
The quasifree γ → d → π 0 n ( p ) photon beam asymmetry, Σ , has been measured at photon energies, E γ , from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49 ∘ to 148 ∘ . In this kinematic region, polarization observables are sensitive to contributions from the Δ ( 1232 ) and N(1440) resonances. The extracted values of Σ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID and Bonn-Gatchina analyses; while a revised SAID fit, including the new Σ measurements, has also been performed. In addition, isospin symmetry is examined as a way to predict π 0 n photoproduction observables, based on fits to published data in the channels π 0 p , π + n and π - p .
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Affiliation(s)
- C. Mullen
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - S. Gardner
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - D. I. Glazier
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - S. J. D. Kay
- SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH9 3FD UK
- Department of Physics, University of Regina, Regina, SK S4S 0A2 Canada
| | - K. Livingston
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - I. I. Strakovsky
- Department of Physics, Institute for Nuclear Studies, The George Washington University, Washington, DC, 20052 USA
| | - R. L. Workman
- Department of Physics, Institute for Nuclear Studies, The George Washington University, Washington, DC, 20052 USA
| | - S. Abt
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - P. Achenbach
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - F. Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, 53115 Bonn, Germany
| | - Z. Ahmed
- Department of Physics, University of Regina, Regina, SK S4S 0A2 Canada
| | | | - J. R. M. Annand
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - M. Bashkanov
- Department of Physics, University of York, Heslington, York, Y010 5DD UK
| | - R. Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, 53115 Bonn, Germany
| | - M. Biroth
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | | | | | - W. J. Briscoe
- Department of Physics, Institute for Nuclear Studies, The George Washington University, Washington, DC, 20052 USA
| | - F. Cividini
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - C. Collicott
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | | | - A. Denig
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - M. Dieterle
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - E. J. Downie
- Department of Physics, Institute for Nuclear Studies, The George Washington University, Washington, DC, 20052 USA
| | - P. Drexler
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - S. Fegan
- Department of Physics, University of York, Heslington, York, Y010 5DD UK
| | - M. I. Ferretti-Bondy
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - D. Ghosal
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | | | - W. Gradl
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - M. Günther
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - G. Gurevic
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - L. Heijkenskjöld
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - D. Hornidge
- Mount Allison University, Sackville, NB E4L3B5 Canada
| | - G. M. Huber
- Department of Physics, University of Regina, Regina, SK S4S 0A2 Canada
| | - N. Jermann
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - A. Kaeser
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - M. Korolija
- Rudjer Boskovic Institute, 10000 Zagreb, Croatia
| | - V. L. Kashevarov
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
- JINR, 141980 Dubna, Russia
| | - B. Krusche
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - V. V. Kulikov
- NRC “Kurchatov Institute”-ITEP, 117218 Moscow, Russia
| | - A. Lazarev
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, 53115 Bonn, Germany
| | - S. Lutterer
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - I. J. D. MacGregor
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | | | - P. P. Martel
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | | | - C. Meier
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - R. Miskimen
- University of Massachusetts, Amherst, MA 01003 USA
| | - M. Mocanu
- Department of Physics, University of York, Heslington, York, Y010 5DD UK
| | - E. Mornacchi
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | | | - M. Oberle
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - M. Ostrick
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - P. Otte
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - D. Paudyal
- Department of Physics, University of Regina, Regina, SK S4S 0A2 Canada
| | - P. Pedroni
- INFN Sezione di Pavia, 27100 Pavia, Italy
| | - A. Powell
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - S. N. Prakhov
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - G. Reicherz
- Institut für Experimentalphysik, Ruhr-University of Bochum, 44801 Bochum, Germany
| | - G. Ron
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem, Israel
| | - T. Rostomyan
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - C. Sfienti
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - V. Sokhoyan
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - K. Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, 53115 Bonn, Germany
| | - O. Steffen
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Th. Strub
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - I. Supek
- Rudjer Boskovic Institute, 10000 Zagreb, Croatia
| | - A. Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, 53115 Bonn, Germany
| | - M. Thiel
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - A. Thomas
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - M. Unverzagt
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | | | - S. Wagner
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - N. K. Walford
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - D. P. Watts
- Department of Physics, University of York, Heslington, York, Y010 5DD UK
| | - D. Werthmüller
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ UK
| | - J. Wettig
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - L. Witthauer
- Institut für Physik, University of Basel, 4056 Basel, Switzerland
| | - M. Wolfes
- Institut für Kernphysik, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - N. Zachariou
- Department of Physics, University of York, Heslington, York, Y010 5DD UK
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5
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Gottschall M, Afzal F, Anisovich AV, Bayadilov D, Beck R, Bichow M, Brinkmann KT, Crede V, Dieterle M, Dietz F, Dutz H, Eberhardt H, Elsner D, Ewald R, Fornet-Ponse K, Friedrich S, Frommberger F, Gridnev A, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoffmeister P, Honisch C, Jude T, Kammer S, Kalinowsky H, Keshelashvili I, Klassen P, Klein F, Klempt E, Koop K, Krusche B, Kube M, Lang M, Lopatin I, Mahlberg P, Makonyi K, Metag V, Meyer W, Müller J, Müllers J, Nanova M, Nikonov V, Novotny R, Piontek D, Reicherz G, Rostomyan T, Sarantsev A, Schmidt C, Schmieden H, Seifen T, Sokhoyan V, Spieker K, Thiel A, Thoma U, Urban M, Pee HV, Walther D, Wendel C, Werthmüller D, Wiedner U, Wilson A, Winnebeck A, Witthauer L, Wunderlich Y. Measurement of the helicity asymmetry E for the reaction γ p → π 0 p : The CBELSA/TAPS Collaboration. Eur Phys J A Hadron Nucl 2021; 57:40. [PMID: 33551676 PMCID: PMC7840663 DOI: 10.1140/epja/s10050-020-00334-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 11/28/2020] [Indexed: 06/12/2023]
Abstract
A measurement of the double-polarization observable E for the reaction γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C4 H9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range fromE γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.
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Affiliation(s)
- M. Gottschall
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - F. Afzal
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - A. V. Anisovich
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - D. Bayadilov
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R. Beck
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Bichow
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | | | - V. Crede
- Department of Physics, Florida State University, Tallahassee, FL 32306 USA
| | - M. Dieterle
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - F. Dietz
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - H. Dutz
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - H. Eberhardt
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - D. Elsner
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - R. Ewald
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | | | - St. Friedrich
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - F. Frommberger
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - A. Gridnev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - M. Grüner
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - E. Gutz
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - Ch. Hammann
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - J. Hannappel
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - J. Hartmann
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - W. Hillert
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - Ph. Hoffmeister
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - Ch. Honisch
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - T. Jude
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - S. Kammer
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - H. Kalinowsky
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | | | - P. Klassen
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - F. Klein
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - E. Klempt
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - K. Koop
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - B. Krusche
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - M. Kube
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Lang
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - I. Lopatin
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - P. Mahlberg
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - K. Makonyi
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - V. Metag
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - W. Meyer
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | - J. Müller
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - J. Müllers
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Nanova
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - V. Nikonov
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R. Novotny
- Physikalisches Institut, Universität Gießen, Gießen, Germany
| | - D. Piontek
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - G. Reicherz
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | - T. Rostomyan
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - A. Sarantsev
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - Ch. Schmidt
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - H. Schmieden
- Physikalisches Institut, Universität Bonn, Bonn, Germany
| | - T. Seifen
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - V. Sokhoyan
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - K. Spieker
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - A. Thiel
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - U. Thoma
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - M. Urban
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - H. van Pee
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - D. Walther
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - Ch. Wendel
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - D. Werthmüller
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - U. Wiedner
- Institut für Experimentalphysik I, Ruhr–Universität Bochum, Bochum, Germany
| | - A. Wilson
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
- Department of Physics, Florida State University, Tallahassee, FL 32306 USA
| | - A. Winnebeck
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
| | - L. Witthauer
- Physikalisches Institut, Universität Basel, Basel, Switzerland
| | - Y. Wunderlich
- Helmholtz–Institut für Strahlen– und Kernphysik, Universität Bonn, Bonn, Germany
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6
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Afzal F, Wunderlich Y, Anisovich AV, Bayadilov D, Beck R, Becker M, Blanke E, Brinkmann KT, Ciupka S, Crede V, Dieterle M, Dutz H, Elsner D, Friedrich S, Frommberger F, Gridnev A, Gottschall M, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoff J, Hoffmeister P, Honisch C, Jude T, Kalinowsky H, Kalischewski F, Keshelashvili I, Klassen P, Klein F, Klempt E, Koop K, Kroenert P, Krusche B, Lang M, Lopatin I, Mahlberg P, Meißner UG, Messi F, Metag V, Meyer W, Mitlasóczki B, Müller J, Müllers J, Nanova M, Nikonov K, Nikonov V, Novinskiy V, Novotny R, Piontek D, Reicherz G, Richter L, Rönchen D, Rostomyan T, Salisbury B, Sarantsev A, Schaab D, Schmidt C, Schmieden H, Schultes J, Seifen T, Sokhoyan V, Sowa C, Spieker K, Stausberg N, Thiel A, Thoma U, Triffterer T, Urban M, Urff G, van Pee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A, Witthauer L. Observation of the pη^{'} Cusp in the New Precise Beam Asymmetry Σ Data for γp→pη. Phys Rev Lett 2020; 125:152002. [PMID: 33095637 DOI: 10.1103/physrevlett.125.152002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/24/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.
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Affiliation(s)
- F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - Y Wunderlich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - A V Anisovich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - D Bayadilov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M Becker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - E Blanke
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - K-Th Brinkmann
- II. Physikalisches Institut, Universität Giessen, Germany
| | - S Ciupka
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - V Crede
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - M Dieterle
- Physikalisches Institut, Universität Basel, Switzerland
| | - H Dutz
- Physikalisches Institut, Universität Bonn, Germany
| | - D Elsner
- Physikalisches Institut, Universität Bonn, Germany
| | - S Friedrich
- II. Physikalisches Institut, Universität Giessen, Germany
| | | | - A Gridnev
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - M Gottschall
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M Grüner
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - E Gutz
- II. Physikalisches Institut, Universität Giessen, Germany
| | - C Hammann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - J Hannappel
- Physikalisches Institut, Universität Bonn, Germany
| | - J Hartmann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - W Hillert
- Physikalisches Institut, Universität Bonn, Germany
| | - J Hoff
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - P Hoffmeister
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - C Honisch
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Jude
- Physikalisches Institut, Universität Bonn, Germany
| | - H Kalinowsky
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - F Kalischewski
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | | | - P Klassen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - F Klein
- Physikalisches Institut, Universität Bonn, Germany
| | - E Klempt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - K Koop
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - P Kroenert
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - B Krusche
- Physikalisches Institut, Universität Basel, Switzerland
| | - M Lang
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - I Lopatin
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - P Mahlberg
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - U-G Meißner
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - F Messi
- Physikalisches Institut, Universität Bonn, Germany
| | - V Metag
- II. Physikalisches Institut, Universität Giessen, Germany
| | - W Meyer
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - B Mitlasóczki
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - J Müller
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - J Müllers
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M Nanova
- II. Physikalisches Institut, Universität Giessen, Germany
| | - K Nikonov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Nikonov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Novinskiy
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - R Novotny
- II. Physikalisches Institut, Universität Giessen, Germany
| | - D Piontek
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - G Reicherz
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - L Richter
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - D Rönchen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Rostomyan
- Physikalisches Institut, Universität Basel, Switzerland
| | - B Salisbury
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - A Sarantsev
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- National Research Centre "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - D Schaab
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - C Schmidt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - H Schmieden
- Physikalisches Institut, Universität Bonn, Germany
| | - J Schultes
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Seifen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - V Sokhoyan
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - C Sowa
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - N Stausberg
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - U Thoma
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - T Triffterer
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - M Urban
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - G Urff
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - H van Pee
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - D Walther
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - Ch Wendel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - U Wiedner
- Institut für Experimentalphysik I, Ruhr Universität Bochum, Germany
| | - A Wilson
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Winnebeck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - L Witthauer
- Physikalisches Institut, Universität Basel, Switzerland
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7
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Dieterle M, Witthauer L, Fix A, Abt S, Achenbach P, Adlarson P, Afzal F, Aguar Bartolome P, Ahmed Z, Annand JRM, Arends HJ, Bashkanov M, Beck R, Biroth M, Borisov N, Braghieri A, Briscoe WJ, Cividini F, Collicott C, Costanza S, Denig A, Dolzhikov AS, Downie EJ, Drexler P, Gardner S, Ghosal D, Glazier DI, Gorodnov I, Gradl W, Günther M, Gurevich D, Heijkenskjöld L, Hornidge D, Huber GM, Käser A, Kashevarov VL, Kay S, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Lazarev A, Lisin V, Livingston K, Lutterer S, MacGregor IJD, Manley DM, Martel PP, Metag V, Meyer W, Middleton DG, Miskimen R, Mornacchi E, Mullen C, Mushkarenkov A, Neganov A, Neiser A, Oberle M, Ostrick M, Otte PB, Paudyal D, Pedroni P, Polonski A, Powell A, Prakhov SN, Reicherz G, Ron G, Rostomyan T, Sarty A, Sfienti C, Sokhoyan V, Spieker K, Steffen O, Strakovsky II, Strub T, Supek I, Thiel A, Thiel M, Thomas A, Unverzagt M, Usov YA, Wagner S, Walford NK, Watts DP, Werthmüller D, Wettig J, Wolfes M, Zana LA. Helicity-Dependent Cross Sections for the Photoproduction of π^{0} Pairs from Nucleons. Phys Rev Lett 2020; 125:062001. [PMID: 32845675 DOI: 10.1103/physrevlett.125.062001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/17/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
The double-polarization observable E and helicity-dependent cross sections σ_{1/2}, σ_{3/2} have been measured for the photoproduction of π^{0} pairs off quasifree protons and neutrons at the Mainz MAMI accelerator with the Crystal Ball/TAPS setup. A circularly polarized photon beam was produced by bremsstrahlung from longitudinally polarized electrons and impinged on a longitudinally polarized deuterated butanol target. The reaction products were detected with an almost 4π covering calorimeter. The results reveal for the first time the helicity- and isospin-dependent structure of the γN→Nπ^{0}π^{0} reaction. They are compared to predictions from reaction models in view of nucleon resonance contributions and also to a refit of one model that predicted results for the proton and for the neutron target. The comparison of the prediction and the refit demonstrates the large impact of the new data.
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Affiliation(s)
- M Dieterle
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - L Witthauer
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634034 Tomsk, Russia
| | - S Abt
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - P Achenbach
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P Adlarson
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
| | - P Aguar Bartolome
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Z Ahmed
- University of Regina, Regina, Saskatchewan S4S-0A2 Canada
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Bashkanov
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
| | - M Biroth
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Braghieri
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - F Cividini
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - C Collicott
- Department of Astronomy and Physics, Saint Mary's University, E4L1E6 Halifax, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - A Denig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - A S Dolzhikov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - E J Downie
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - P Drexler
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - D Ghosal
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - I Gorodnov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - W Gradl
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Günther
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - D Gurevich
- Institute for Nuclear Research, RU-125047 Moscow, Russia
| | - L Heijkenskjöld
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L1E6, Canada
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S-0A2 Canada
| | - A Käser
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Kay
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - I Keshelashvili
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, RU-125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - V Lisin
- Institute for Nuclear Research, RU-125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - S Lutterer
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242, USA
| | - P P Martel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L3B5, Canada
| | - V Metag
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - W Meyer
- Institut für Experimentalphysik, Ruhr Universität, 44780 Bochum, Germany
| | - D G Middleton
- Mount Allison University, Sackville, New Brunswick E4L3B5, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - E Mornacchi
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - C Mullen
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - A Mushkarenkov
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - A Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Neiser
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Oberle
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Paudyal
- University of Regina, Regina, Saskatchewan S4S-0A2 Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Pavia, Italy
| | - A Polonski
- Institute for Nuclear Research, RU-125047 Moscow, Russia
| | - A Powell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - S N Prakhov
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr Universität, 44780 Bochum, Germany
| | - G Ron
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - T Rostomyan
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Mary's University, E4L1E6 Halifax, Canada
| | - C Sfienti
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - V Sokhoyan
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
| | - O Steffen
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052, USA
| | - T Strub
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, D-53115 Bonn, Germany
| | - M Thiel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Wagner
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N K Walford
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - D P Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Werthmüller
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - J Wettig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Wolfes
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - L A Zana
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
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8
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Kashevarov VL, Ott P, Prakhov S, Adlarson P, Afzal F, Ahmed Z, Akondi CS, Annand JRM, Arends HJ, Beck R, Braghieri A, Briscoe WJ, Cividini F, Codling R, Collicott C, Costanza S, Denig A, Downie EJ, Dieterle M, Ferretti Bondy MI, Fil'kov LV, Fix A, Gardner S, Garni S, Glazier DI, Glowa D, Gradl W, Gurevich G, Hamilton DJ, Hornidge D, Howdle D, Huber GM, Käser A, Kay S, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Linturi J, Lisin V, Livingston K, MacGregor IJD, MacRae R, Mancell J, Manley DM, Martel PP, McGeorge JC, McNicol E, Middleton DG, Miskimen R, Mornacchi E, Mullen C, Mushkarenkov A, Neiser A, Oberle M, Ostrick M, Otte PB, Oussena B, Paudyal D, Pedroni P, Polyanski VV, Rajabi A, Reicherz G, Robinson J, Rosner G, Rostomyan T, Sarty A, Schott DM, Schumann S, Sfienti C, Sokhoyan V, Spieker K, Steffen O, Strandberg B, Strakovsky II, Strub T, Supek I, Taragin MF, Thiel A, Thiel M, Tiator L, Thomas A, Unverzagt M, Wagner S, Watts DP, Werthmüller D, Wettig J, Witthauer L, Wolfes M, Workman RL, Zana L. Study of η and η' Photoproduction at MAMI. Phys Rev Lett 2017; 118:212001. [PMID: 28598665 DOI: 10.1103/physrevlett.118.212001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Indexed: 06/07/2023]
Abstract
The reactions γp→ηp and γp→η^{'}p are measured from their thresholds up to the center-of-mass energy W=1.96 GeV with the tagged-photon facilities at the Mainz Microtron, MAMI. Differential cross sections are obtained with unprecedented statistical accuracy, providing fine energy binning and full production-angle coverage. A strong cusp is observed in the total cross section for η photoproduction at the energies in the vicinity of the η^{'} threshold, W=1896 MeV (E_{γ}=1447 MeV). Within the framework of a revised ηMAID isobar model, the cusp, in connection with a steep rise of the η^{'} total cross section from its threshold, can only be explained by a strong coupling of the poorly known N(1895)1/2^{-} state to both ηp and η^{'}p. Including the new high-accuracy results in the ηMAID fit to available η and η^{'} photoproduction data allows the determination of the N(1895)1/2^{-} properties.
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Affiliation(s)
- V L Kashevarov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - P Ott
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Prakhov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - P Adlarson
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - Z Ahmed
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - C S Akondi
- Kent State University, Kent, Ohio 44242-0001, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | | | - W J Briscoe
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - F Cividini
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R Codling
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - C Collicott
- Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
- Dipartimento di Fisica, Università di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - E J Downie
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - M Dieterle
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M I Ferretti Bondy
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634034 Tomsk, Russia
| | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - S Garni
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Glowa
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - G Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - D J Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - A Käser
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - S Kay
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - I Keshelashvili
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - J Linturi
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - R MacRae
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
| | - P P Martel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - J C McGeorge
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E McNicol
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D G Middleton
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - E Mornacchi
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Mullen
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - A Mushkarenkov
- INFN Sezione di Pavia, I-27100 Pavia, Italy
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - A Neiser
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Oberle
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - D Paudyal
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | | | - A Rajabi
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - J Robinson
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Rosner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - T Rostomyan
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
| | - D M Schott
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - S Schumann
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Sfienti
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - V Sokhoyan
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - O Steffen
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B Strandberg
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I I Strakovsky
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - Th Strub
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - M F Taragin
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - M Thiel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L Tiator
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Wagner
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D P Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Werthmüller
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - J Wettig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L Witthauer
- Departement für Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R L Workman
- The George Washington University, Washington, D.C. 20052-0001, USA
| | - L Zana
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
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9
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Witthauer L, Dieterle M, Abt S, Achenbach P, Afzal F, Ahmed Z, Annand JRM, Arends HJ, Bashkanov M, Beck R, Biroth M, Borisov NS, Braghieri A, Briscoe WJ, Cividini F, Costanza S, Collicott C, Denig A, Downie EJ, Drexler P, Ferretti-Bondy MI, Gardner S, Garni S, Glazier DI, Glowa D, Gradl W, Günther M, Gurevich GM, Hamilton D, Hornidge D, Huber GM, Käser A, Kashevarov VL, Kay S, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Lazarev AB, Linturi JM, Lisin V, Livingston K, Lutterer S, MacGregor IJD, Mancell J, Manley DM, Martel PP, Metag V, Meyer W, Miskimen R, Mornacchi E, Mushkarenkov A, Neganov AB, Neiser A, Oberle M, Ostrick M, Otte PB, Paudyal D, Pedroni P, Polonski A, Prakhov SN, Rajabi A, Reicherz G, Ron G, Rostomyan T, Sarty A, Sfienti C, Sikora MH, Sokhoyan V, Spieker K, Steffen O, Strakovski II, Strub T, Supek I, Thiel A, Thiel M, Thomas A, Unverzagt M, Usov YA, Wagner S, Walford NK, Watts DP, Werthmüller D, Wettig J, Wolfes M, Zana L. Insight into the Narrow Structure in η Photoproduction on the Neutron from Helicity-Dependent Cross Sections. Phys Rev Lett 2016; 117:132502. [PMID: 27715117 DOI: 10.1103/physrevlett.117.132502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Indexed: 06/06/2023]
Abstract
The double polarization observable E and the helicity dependent cross sections σ_{1/2} and σ_{3/2} were measured for η photoproduction from quasifree protons and neutrons. The circularly polarized tagged photon beam of the A2 experiment at the Mainz MAMI accelerator was used in combination with a longitudinally polarized deuterated butanol target. The almost 4π detector setup of the Crystal Ball and TAPS is ideally suited to detect the recoil nucleons and the decay photons from η→2γ and η→3π^{0}. The results show that the narrow structure previously observed in η photoproduction from the neutron is only apparent in σ_{1/2} and hence, most likely related to a spin-1/2 amplitude. Nucleon resonances that contribute to this partial wave in η production are only N 1/2^{-} (S_{11}) and N 1/2^{+} (P_{11}). Furthermore, the extracted Legendre coefficients of the angular distributions for σ_{1/2} are in good agreement with recent reaction model predictions assuming a narrow resonance in the P_{11} wave as the origin of this structure.
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Affiliation(s)
- L Witthauer
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - M Dieterle
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - S Abt
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - P Achenbach
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - F Afzal
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - Z Ahmed
- University of Regina, Regina, SK S4S 0A2 Canada
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Bashkanov
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Biroth
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N S Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | | | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052-0001, USA
| | - F Cividini
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - C Collicott
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - A Denig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - E J Downie
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052-0001, USA
| | - P Drexler
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | | | - S Gardner
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - S Garni
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
| | - D Glowa
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Günther
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - G M Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - D Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - G M Huber
- University of Regina, Regina, SK S4S 0A2 Canada
| | - A Käser
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - S Kay
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
| | - I Keshelashvili
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR 10000 Zagreb, Croatia
| | - B Krusche
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - A B Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - J M Linturi
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - S Lutterer
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
| | - P P Martel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - V Metag
- II. Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - W Meyer
- Institut für Experimentalphysik, Ruhr Universität, 44780 Bochum, Germany
| | - R Miskimen
- University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - E Mornacchi
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - A Mushkarenkov
- Institute for Nuclear Research, 125047 Moscow, Russia
- University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - A B Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Neiser
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Oberle
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Paudyal
- University of Regina, Regina, SK S4S 0A2 Canada
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Polonski
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - S N Prakhov
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- University of California at Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Rajabi
- University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr Universität, 44780 Bochum, Germany
| | - G Ron
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - T Rostomyan
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - C Sfienti
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M H Sikora
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
| | - V Sokhoyan
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052-0001, USA
| | - K Spieker
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - O Steffen
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - I I Strakovski
- Center for Nuclear Studies, The George Washington University, Washington, DC 20052-0001, USA
| | - Th Strub
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR 10000 Zagreb, Croatia
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Thiel
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - S Wagner
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - N K Walford
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - D P Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
| | - D Werthmüller
- Department of Physics, University of Basel, CH-4056 Basel, Switzerland
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Wettig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Wolfes
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - L Zana
- SUPA School of Physics, University of Edinburgh, Edinburgh EEH9 3JZ, United Kingdom
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10
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Alef S, Bauer P, Bayadilov D, Beck R, Becker M, Bella A, Bielefeldt P, Böse S, Braghieri A, Brinkmann K, Cole P, Di Salvo R, Dutz H, Elsner D, Fantini A, Freyermuth O, Friedrich S, Frommberger F, Ganenko V, Geffers D, Gervino G, Ghio F, Görtz S, Gridnev A, Gutz E, Hammann D, Hannappel J, Hillert W, Ignatov A, Jahn R, Joosten R, Jude T, Klein F, Knaust J, Kohl K, Koop K, Krusche B, Lapik A, Levi Sandri P, Lopatin I, Mandaglio G, Messi F, Messi R, Metag V, Moricciani D, Mushkarenkov A, Nanova M, Nedorezov V, Novinskiy D, Pedroni P, Reitz B, Romaniuk M, Rostomyan T, Rudnev N, Schaerf C, Scheluchin G, Schmieden H, Stugelev A, Sumachev V, Tarakanov V, Vegna V, Walther D, Watts D, Zaunick H, Zimmermann T. Commissioning and initial experimental program of the BGO-OD experiment at ELSA. EPJ Web Conf 2016. [DOI: 10.1051/epjconf/201613007013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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11
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Martel PP, Miskimen R, Aguar-Bartolome P, Ahrens J, Akondi CS, Annand JRM, Arends HJ, Barnes W, Beck R, Bernstein A, Borisov N, Braghieri A, Briscoe WJ, Cherepnya S, Collicott C, Costanza S, Denig A, Dieterle M, Downie EJ, Fil'kov LV, Garni S, Glazier DI, Gradl W, Gurevich G, Hall Barrientos P, Hamilton D, Hornidge D, Howdle D, Huber GM, Jude TC, Kaeser A, Kashevarov VL, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Lazarev A, Lisin V, Livingston K, MacGregor IJD, Mancell J, Manley DM, Meyer W, Middleton DG, Mushkarenkov A, Nefkens BMK, Neganov A, Nikolaev A, Oberle M, Ortega Spina H, Ostrick M, Ott P, Otte PB, Oussena B, Pedroni P, Polonski A, Polyansky V, Prakhov S, Rajabi A, Reicherz G, Rostomyan T, Sarty A, Schrauf S, Schumann S, Sikora MH, Starostin A, Steffen O, Strakovsky II, Strub T, Supek I, Thiel M, Tiator L, Thomas A, Unverzagt M, Usov Y, Watts DP, Witthauer L, Werthmüller D, Wolfes M. Measurements of double-polarized compton scattering asymmetries and extraction of the proton spin polarizabilities. Phys Rev Lett 2015; 114:112501. [PMID: 25839263 DOI: 10.1103/physrevlett.114.112501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Indexed: 06/04/2023]
Abstract
The spin polarizabilities of the nucleon describe how the spin of the nucleon responds to an incident polarized photon. The most model-independent way to extract the nucleon spin polarizabilities is through polarized Compton scattering. Double-polarized Compton scattering asymmetries on the proton were measured in the Δ(1232) region using circularly polarized incident photons and a transversely polarized proton target at the Mainz Microtron. Fits to asymmetry data were performed using a dispersion model calculation and a baryon chiral perturbation theory calculation, and a separation of all four proton spin polarizabilities in the multipole basis was achieved. The analysis based on a dispersion model calculation yields γ(E1E1)=-3.5±1.2, γ(M1M1)=3.16±0.85, γ(E1M2)=-0.7±1.2, and γ(M1E2)=1.99±0.29, in units of 10(-4) fm(4).
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Affiliation(s)
- P P Martel
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Department of Physics, Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - R Miskimen
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | | | - J Ahrens
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - C S Akondi
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - W Barnes
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - A Bernstein
- Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Borisov
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | | | - W J Briscoe
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - S Cherepnya
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - C Collicott
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M Dieterle
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - E J Downie
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - S Garni
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - G Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - P Hall Barrientos
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Department of Physics, Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- Department of Physics, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - T C Jude
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - A Kaeser
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | | | - I Keshelashvili
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancell
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Department of Physics, Kent State University, Kent, Ohio 44242, USA
| | - W Meyer
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - D G Middleton
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Department of Physics, Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - A Mushkarenkov
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - B M K Nefkens
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Neganov
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | - A Nikolaev
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - M Oberle
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - H Ortega Spina
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M Ostrick
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - P Ott
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Polonski
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - V Polyansky
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - S Prakhov
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Rajabi
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - T Rostomyan
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Schrauf
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - S Schumann
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M H Sikora
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - A Starostin
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - O Steffen
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - T Strub
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - M Thiel
- II. Physikalisches Institut, Universität Giessen, D-35392 Giessen, Germany
| | - L Tiator
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn, Germany
| | - Y Usov
- Joint Institute for Nuclear Research (JINR), 141980 Dubna, Russia
| | - D P Watts
- School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - L Witthauer
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - D Werthmüller
- Departement Physik, Universität Basel, CH-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
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12
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Akondi CS, Annand JRM, Arends HJ, Beck R, Bernstein A, Borisov N, Braghieri A, Briscoe WJ, Cherepnya S, Collicott C, Costanza S, Downie EJ, Dieterle M, Fix A, Fil'kov LV, Garni S, Glazier DI, Gradl W, Gurevich G, Hall Barrientos P, Hamilton D, Hornidge D, Howdle D, Huber GM, Kashevarov VL, Keshelashvili I, Kondratiev R, Korolija M, Krusche B, Lazarev A, Lisin V, Livingston K, MacGregor IJD, Mancel J, Manley DM, Martel P, McNicoll EF, Meyer W, Middleton D, Miskimen R, Mushkarenkov A, Nefkens BMK, Neganov A, Nikolaev A, Oberle M, Ostrick M, Ortega H, Ott P, Otte PB, Oussena B, Pedroni P, Polonski A, Polyanski VV, Prakhov S, Reicherz G, Rostomyan T, Sarty A, Schumann S, Steffen O, Strakovsky II, Strub T, Supek I, Tiator L, Thomas A, Unverzagt M, Usov YA, Watts DP, Werthmüller D, Witthauer L, Wolfes M. Measurement of the transverse target and beam-target asymmetries in η meson photoproduction at MAMI. Phys Rev Lett 2014; 113:102001. [PMID: 25238349 DOI: 10.1103/physrevlett.113.102001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Indexed: 06/03/2023]
Abstract
We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the γ[over →]p[over →]→ηp reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. All existing model predictions fail to reproduce the new data indicating a significant impact on our understanding of the underlying dynamics of η meson photoproduction. The peculiar nodal structure observed in existing T data close to threshold is not confirmed.
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Affiliation(s)
- C S Akondi
- Kent State University, Kent, Ohio 44242-0001, USA
| | - J R M Annand
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - A Bernstein
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - N Borisov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | | | - W J Briscoe
- The George Washington University, Washington, DC 20052-0001, USA
| | - S Cherepnya
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - C Collicott
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Costanza
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - E J Downie
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and The George Washington University, Washington, DC 20052-0001, USA
| | - M Dieterle
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, 634034 Tomsk, Russia
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - S Garni
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - D I Glazier
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom and SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W Gradl
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - G Gurevich
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - P Hall Barrientos
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Hamilton
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - V L Kashevarov
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and Lebedev Physical Institute, 119991 Moscow, Russia
| | - I Keshelashvili
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - B Krusche
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Lazarev
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - J Mancel
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44242-0001, USA
| | - P Martel
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA and University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - E F McNicoll
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - W Meyer
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - D Middleton
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - R Miskimen
- University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - A Mushkarenkov
- INFN Sezione di Pavia, I-27100 Pavia, Italy and University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - B M K Nefkens
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Neganov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - A Nikolaev
- Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - M Oberle
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - H Ortega
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P Ott
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and The George Washington University, Washington, DC 20052-0001, USA
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - A Polonski
- Institute for Nuclear Research, 125047 Moscow, Russia
| | | | - S Prakhov
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - G Reicherz
- Institut für Experimentalphysik, Ruhr-Universität, D-44780 Bochum, Germany
| | - T Rostomyan
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Sarty
- Department of Astronomy and Physics, Saint Marys University, Halifax, Nova Scotia B3H 3C3, Canada
| | - S Schumann
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany and Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - O Steffen
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - I I Strakovsky
- The George Washington University, Washington, DC 20052-0001, USA
| | - Th Strub
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - L Tiator
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Thomas
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Yu A Usov
- Joint Institute for Nuclear Research, 141980 Dubna, Russia
| | - D P Watts
- SUPA School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Werthmüller
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - L Witthauer
- Departement für Physik, University of Basel, CH-4056 Basel, Switzerland
| | - M Wolfes
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
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13
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Hartmann J, Dutz H, Anisovich AV, Bayadilov D, Beck R, Becker M, Beloglazov Y, Berlin A, Bichow M, Böse S, Brinkmann KT, Crede V, Dieterle M, Eberhardt H, Elsner D, Fornet-Ponse K, Friedrich S, Frommberger F, Funke C, Gottschall M, Gridnev A, Grüner M, Gutz E, Hammann C, Hannappel J, Hannen V, Herick J, Hillert W, Hoffmeister P, Honisch C, Jahn O, Jude T, Käser A, Kaiser D, Kalinowsky H, Kalischewski F, Klassen P, Keshelashvili I, Klein F, Klempt E, Koop K, Krusche B, Kube M, Lang M, Lopatin I, Makonyi K, Messi F, Metag V, Meyer W, Müller J, Nanova M, Nikonov V, Novinski D, Novotny R, Piontek D, Rosenbaum C, Roth B, Reicherz G, Rostomyan T, Sarantsev A, Schmidt C, Schmieden H, Schmitz R, Seifen T, Sokhoyan V, Thämer P, Thiel A, Thoma U, Urban M, van Pee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A, Witthauer L, Wunderlich Y. N(1520) 3/2(-) helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions. Phys Rev Lett 2014; 113:062001. [PMID: 25148317 DOI: 10.1103/physrevlett.113.062001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Indexed: 06/03/2023]
Abstract
New data on the polarization observables T, P, and H for the reaction γp→pπ(0) are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses.
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Affiliation(s)
- J Hartmann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Dutz
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - A V Anisovich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - D Bayadilov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R Beck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Becker
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Y Beloglazov
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - A Berlin
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - M Bichow
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - S Böse
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K-Th Brinkmann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Crede
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - M Dieterle
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - H Eberhardt
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - D Elsner
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - K Fornet-Ponse
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - St Friedrich
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - F Frommberger
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ch Funke
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Gottschall
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Gridnev
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - M Grüner
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - E Gutz
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - Ch Hammann
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - J Hannappel
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - V Hannen
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - J Herick
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - W Hillert
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ph Hoffmeister
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Honisch
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - O Jahn
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - T Jude
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - A Käser
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - D Kaiser
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Kalinowsky
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - F Kalischewski
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - P Klassen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Keshelashvili
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - F Klein
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - E Klempt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K Koop
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - B Krusche
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - M Kube
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Lang
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Lopatin
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - K Makonyi
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - F Messi
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - V Metag
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - W Meyer
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Müller
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Nanova
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Nikonov
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - D Novinski
- Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - R Novotny
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - D Piontek
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - C Rosenbaum
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - B Roth
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - G Reicherz
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - T Rostomyan
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - A Sarantsev
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina 188300, Russia
| | - Ch Schmidt
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Schmieden
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - R Schmitz
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - T Seifen
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - V Sokhoyan
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ph Thämer
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Thiel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Thoma
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Urban
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H van Pee
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - D Walther
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Wendel
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Wiedner
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - A Wilson
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Winnebeck
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - L Witthauer
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - Y Wunderlich
- Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, 53115 Bonn, Germany
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14
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Tarbert CM, Watts DP, Glazier DI, Aguar P, Ahrens J, Annand JRM, Arends HJ, Beck R, Bekrenev V, Boillat B, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Codling R, Downie EJ, Foehl K, Grabmayr P, Gregor R, Heid E, Hornidge D, Jahn O, Kashevarov VL, Knezevic A, Kondratiev R, Korolija M, Kotulla M, Krambrich D, Krusche B, Lang M, Lisin V, Livingston K, Lugert S, MacGregor IJD, Manley DM, Martinez M, McGeorge JC, Mekterovic D, Metag V, Nefkens BMK, Nikolaev A, Novotny R, Owens RO, Pedroni P, Polonski A, Prakhov SN, Price JW, Rosner G, Rost M, Rostomyan T, Schadmand S, Schumann S, Sober D, Starostin A, Supek I, Thomas A, Unverzagt M, Walcher T, Zana L, Zehr F. Neutron skin of (208)pb from coherent pion photoproduction. Phys Rev Lett 2014; 112:242502. [PMID: 24996085 DOI: 10.1103/physrevlett.112.242502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Indexed: 06/03/2023]
Abstract
Information on the size and shape of the neutron skin on (208)Pb is extracted from coherent pion photoproduction cross sections measured using the Crystal Ball detector together with the Glasgow tagger at the MAMI electron beam facility. On exploitation of an interpolated fit of a theoretical model to the measured cross sections, the half-height radius and diffuseness of the neutron distribution are found to be c(n)=6.70±0.03(stat.) fm and a(n)=0.55±0.01(stat.)(-0.03)(+0.02)(sys.) fm, respectively, corresponding to a neutron skin thickness Δr(np)=0.15±0.03(stat.)(-0.03)(+0.01)(sys.) fm. The results give the first successful extraction of a neutron skin thickness with an electromagnetic probe and indicate that the skin of (208)Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron-rich matter.
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Affiliation(s)
- C M Tarbert
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D P Watts
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D I Glazier
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - P Aguar
- Institut für Kernphysik, University of Mainz, Germany
| | - J Ahrens
- Institut für Kernphysik, University of Mainz, Germany
| | - J R M Annand
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, Germany
| | - R Beck
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, Germany
| | - V Bekrenev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Boillat
- Institut für Physik, University of Basel, Basel, Switzerland
| | | | - D Branford
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, D.C. 20052, USA
| | - J Brudvik
- University of California at Los Angeles, Los Angeles, California 90095, USA
| | | | - R Codling
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E J Downie
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - K Foehl
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - P Grabmayr
- Physikalisches Institut Universität Tübingen, Tübingen, Germany
| | - R Gregor
- II. Physikalisches Institut, University of Giessen, Germany
| | - E Heid
- Institut für Kernphysik, University of Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - O Jahn
- Institut für Kernphysik, University of Mainz, Germany
| | | | - A Knezevic
- Rudjer Boskovic Institute, Zagreb, Croatia
| | | | - M Korolija
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - M Kotulla
- Institut für Physik, University of Basel, Basel, Switzerland
| | - D Krambrich
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, Germany
| | - B Krusche
- Institut für Physik, University of Basel, Basel, Switzerland
| | - M Lang
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, Germany
| | - V Lisin
- Institute for Nuclear Research, Moscow, Russia
| | - K Livingston
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - S Lugert
- II. Physikalisches Institut, University of Giessen, Germany
| | - I J D MacGregor
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D M Manley
- Kent State University, Kent, Ohio 44240, USA
| | - M Martinez
- Institut für Kernphysik, University of Mainz, Germany
| | - J C McGeorge
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - V Metag
- II. Physikalisches Institut, University of Giessen, Germany
| | - B M K Nefkens
- University of California at Los Angeles, Los Angeles, California 90095, USA
| | - A Nikolaev
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, Germany
| | - R Novotny
- II. Physikalisches Institut, University of Giessen, Germany
| | - R O Owens
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - A Polonski
- Institute for Nuclear Research, Moscow, Russia
| | - S N Prakhov
- University of California at Los Angeles, Los Angeles, California 90095, USA
| | - J W Price
- University of California at Los Angeles, Los Angeles, California 90095, USA
| | - G Rosner
- SUPA, Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - M Rost
- Institut für Kernphysik, University of Mainz, Germany
| | | | - S Schadmand
- II. Physikalisches Institut, University of Giessen, Germany
| | - S Schumann
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, Germany
| | - D Sober
- The Catholic University of America, Washington, D.C. 20064, USA
| | - A Starostin
- University of California at Los Angeles, Los Angeles, California 90095, USA
| | - I Supek
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - A Thomas
- Institut für Kernphysik, University of Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University Bonn, Germany
| | - Th Walcher
- Institut für Kernphysik, University of Mainz, Germany
| | - L Zana
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - F Zehr
- Institut für Physik, University of Basel, Basel, Switzerland
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15
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Dieterle M, Keshelashvili I, Ahrens J, Annand JRM, Arends HJ, Bantawa K, Bartolome PA, Beck R, Bekrenev V, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Demissie B, Downie EJ, Drexler P, Fil'kov LV, Fix A, Glazier DI, Hamilton D, Heid E, Hornidge D, Howdle D, Huber GM, Jaegle I, Jahn O, Jude TC, Käser A, Kashevarov VL, Kondratiev R, Korolija M, Kruglov SP, Krusche B, Kulbardis A, Lisin V, Livingston K, MacGregor IJD, Maghrbi Y, Mancell J, Manley DM, Marinides Z, Martinez M, McGeorge JC, McNicoll E, Mekterovic D, Metag V, Micanovic S, Middleton DG, Mushkarenkov A, Nefkens BMK, Nikolaev A, Novotny R, Oberle M, Ostrick M, Oussena B, Pedroni P, Pheron F, Polonski A, Prakhov SN, Robinson J, Rosner G, Rostomyan T, Schumann S, Sikora MH, Sober D, Starostin A, Supek I, Thiel M, Thomas A, Unverzagt M, Watts DP, Werthmüller D, Witthauer L. Photoproduction of π0 mesons off neutrons in the nucleon resonance region. Phys Rev Lett 2014; 112:142001. [PMID: 24765945 DOI: 10.1103/physrevlett.112.142001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Indexed: 06/03/2023]
Abstract
Precise angular distributions have been measured for the first time for the photoproduction of π0 mesons off neutrons bound in the deuteron. The effects from nuclear Fermi motion have been eliminated by a complete kinematic reconstruction of the final state. The influence of final-state-interaction effects has been estimated by a comparison of the reaction cross section for quasifree protons bound in the deuteron to the results for free protons and then applied as a correction to the quasifree neutron data. The experiment was performed at the tagged photon facility of the Mainz Microtron MAMI with the Crystal Ball and TAPS detector setup for incident photon energies between 0.45 and 1.4 GeV. The results are compared to the predictions from reaction models and partial-wave analyses based on data from other isospin channels. The model predictions show large discrepancies among each other and the present data will provide much tighter constraints. This is demonstrated by the results of a new analysis in the framework of the Bonn-Gatchina coupled-channel analysis which included the present data.
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Affiliation(s)
- M Dieterle
- Department of Physics, University of Basel, Switzerland
| | | | - J Ahrens
- Institut für Kernphysik, University of Mainz, Germany
| | - J R M Annand
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, Germany
| | - K Bantawa
- Kent State University, Kent, Ohio, USA
| | - P A Bartolome
- Institut für Kernphysik, University of Mainz, Germany
| | - R Beck
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - V Bekrenev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | | | - D Branford
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - W J Briscoe
- Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - J Brudvik
- University of California at Los Angeles, Los Angeles, California, USA
| | | | - B Demissie
- Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - E J Downie
- Institut für Kernphysik, University of Mainz, Germany and Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom and Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - P Drexler
- II. Physikalisches Institut, University of Giessen, Germany
| | | | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk, Russia
| | - D I Glazier
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - D Hamilton
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - E Heid
- Institut für Kernphysik, University of Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - G M Huber
- University of Regina, Regina, Saskatchewan S4S 0A2 Canada
| | - I Jaegle
- Department of Physics, University of Basel, Switzerland
| | - O Jahn
- Institut für Kernphysik, University of Mainz, Germany
| | - T C Jude
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - A Käser
- Department of Physics, University of Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, University of Mainz, Germany and Lebedev Physical Institute, Moscow, Russia
| | | | - M Korolija
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - S P Kruglov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Krusche
- Department of Physics, University of Basel, Switzerland
| | - A Kulbardis
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Lisin
- Institute for Nuclear Research, Moscow, Russia
| | - K Livingston
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - I J D MacGregor
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - Y Maghrbi
- Department of Physics, University of Basel, Switzerland
| | - J Mancell
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | | | - Z Marinides
- Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | - M Martinez
- Institut für Kernphysik, University of Mainz, Germany
| | - J C McGeorge
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - E McNicoll
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | | | - V Metag
- II. Physikalisches Institut, University of Giessen, Germany
| | | | - D G Middleton
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | | | - B M K Nefkens
- University of California at Los Angeles, Los Angeles, California, USA
| | - A Nikolaev
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - R Novotny
- II. Physikalisches Institut, University of Giessen, Germany
| | - M Oberle
- Department of Physics, University of Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, University of Mainz, Germany and Center for Nuclear Studies, The George Washington University, Washington, DC, USA
| | | | - F Pheron
- Department of Physics, University of Basel, Switzerland
| | - A Polonski
- Institute for Nuclear Research, Moscow, Russia
| | - S N Prakhov
- University of California at Los Angeles, Los Angeles, California, USA
| | - J Robinson
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - G Rosner
- Department of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom
| | - T Rostomyan
- Department of Physics, University of Basel, Switzerland
| | - S Schumann
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - M H Sikora
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - D Sober
- The Catholic University of America, Washington, DC, USA
| | - A Starostin
- University of California at Los Angeles, Los Angeles, California, USA
| | - I Supek
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - M Thiel
- Institut für Kernphysik, University of Mainz, Germany and II. Physikalisches Institut, University of Giessen, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, University of Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, University of Bonn, Germany
| | - D P Watts
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
| | - D Werthmüller
- Department of Physics, University of Basel, Switzerland
| | - L Witthauer
- Department of Physics, University of Basel, Switzerland
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16
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Sikora MH, Watts DP, Glazier DI, Aguar-Bartolomé P, Akasoy LK, Annand JRM, Arends HJ, Bantawa K, Beck R, Bekrenev VS, Berghäuser H, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Codling RFB, Demissie BT, Downie EJ, Drexler P, Fil'kov LV, Freehart B, Gregor R, Hamilton D, Heid E, Hornidge D, Howdle DA, Jaegle I, Jahn O, Jude TC, Kashevarov VL, Keshelashvili I, Kondratiev R, Korolija M, Kotulla M, Koulbardis AA, Kruglov SP, Krusche B, Lisin V, Livingston K, MacGregor IJD, Maghrbi Y, Manley DM, Marinides Z, Martinez M, McGeorge JC, McKinnon B, McNicoll EF, Mekterovic D, Metag V, Micanovic S, Middleton DG, Mushkarenkov A, Nefkens BMK, Nikolaev A, Novotny R, Ostrick M, Otte PB, Oussena B, Pedroni P, Pheron F, Polonski A, Prakhov S, Robinson J, Rosner G, Rostomyan T, Schumann S, Sober DI, Starostin A, Strakovsky II, Suarez IM, Supek I, Thiel M, Thomas A, Unverzagt M, Werthmüller D, Workman RL, Zamboni I, Zehr F. Measurement of the 1H(γ, p)π0 reaction using a novel nucleon spin polarimeter. Phys Rev Lett 2014; 112:022501. [PMID: 24484003 DOI: 10.1103/physrevlett.112.022501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Indexed: 06/03/2023]
Abstract
We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon. The measurement pioneers a novel polarimetry technique, which can be applied to many other nuclear and hadron physics experiments. The commissioning reaction of 1H(γ, p)π0 in the range 0.4<Eγ<1.4 GeV validates the technique and provides essential new data to constrain the excitation spectrum of the nucleon.
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Affiliation(s)
- M H Sikora
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D P Watts
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D I Glazier
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - P Aguar-Bartolomé
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - L K Akasoy
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - J R M Annand
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - K Bantawa
- Kent State University, Kent, Ohio 44242, USA
| | - R Beck
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - V S Bekrenev
- Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
| | - H Berghäuser
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | | | - D Branford
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W J Briscoe
- The George Washington University, Washington, D.C. 20052, USA
| | - J Brudvik
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - S Cherepnya
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - R F B Codling
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - B T Demissie
- The George Washington University, Washington, D.C. 20052, USA
| | - E J Downie
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany and SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom and The George Washington University, Washington, D.C. 20052, USA
| | - P Drexler
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - L V Fil'kov
- Lebedev Physical Institute, 119991 Moscow, Russia
| | - B Freehart
- The George Washington University, Washington, D.C. 20052, USA
| | - R Gregor
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - D Hamilton
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E Heid
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany and The George Washington University, Washington, D.C. 20052, USA
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L3B5, Canada
| | - D A Howdle
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I Jaegle
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
| | - O Jahn
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - T C Jude
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | | | - I Keshelashvili
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
| | - R Kondratiev
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - M Korolija
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - M Kotulla
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - A A Koulbardis
- Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
| | - S P Kruglov
- Petersburg Nuclear Physics Institute, 188300 Gatchina, Russia
| | - B Krusche
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
| | - V Lisin
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - K Livingston
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Maghrbi
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
| | - D M Manley
- Kent State University, Kent, Ohio 44242, USA
| | - Z Marinides
- The George Washington University, Washington, D.C. 20052, USA
| | - M Martinez
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - J C McGeorge
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - B McKinnon
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E F McNicoll
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - D Mekterovic
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - V Metag
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - S Micanovic
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - D G Middleton
- Mount Allison University, Sackville, New Brunswick E4L3B5, Canada
| | | | - B M K Nefkens
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - A Nikolaev
- Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, D-53115 Bonn, Germany
| | - R Novotny
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - M Ostrick
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - P B Otte
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany and The George Washington University, Washington, D.C. 20052, USA
| | - P Pedroni
- INFN Sezione di Pavia, I-27100 Pavia, Italy
| | - F Pheron
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
| | - A Polonski
- Institute for Nuclear Research, 125047 Moscow, Russia
| | - S Prakhov
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - J Robinson
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Rosner
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - S Schumann
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D I Sober
- The Catholic University of America, Washington D.C. 20064, USA
| | - A Starostin
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - I I Strakovsky
- The George Washington University, Washington, D.C. 20052, USA
| | - I M Suarez
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - I Supek
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - M Thiel
- II Physikalisches Institut, University of Giessen, D-35392 Giessen, Germany
| | - A Thomas
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - D Werthmüller
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
| | - R L Workman
- The George Washington University, Washington, D.C. 20052, USA
| | - I Zamboni
- Rudjer Boskovic Institute, HR-10000 Zagreb, Croatia
| | - F Zehr
- Department Physik, University of Basel, CH-4056 Basel, Switzerland
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17
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Gottschall M, Anisovich AV, Bantes B, Bayadilov D, Beck R, Bichow M, Böse S, Brinkmann KT, Challand T, Crede V, Dietz F, Dutz H, Eberhardt H, Elsner D, Ewald R, Fornet-Ponse K, Friedrich S, Frommberger F, Funke C, Gridnev A, Grüner M, Gutz E, Hammann C, Hannappel J, Hartmann J, Hillert W, Hoffmeister P, Honisch C, Jaegle I, Kaiser D, Kalinowsky H, Kammer S, Keshelashvili I, Klein F, Klempt E, Koop K, Krusche B, Kube M, Lang M, Lopatin I, Maghrbi Y, Makonyi K, Metag V, Meyer W, Müller J, Nanova M, Nikonov V, Novotny R, Piontek D, Reicherz G, Rostomyan T, Sarantsev A, Schaepe S, Schmidt C, Schmieden H, Schmitz R, Seifen T, Sokhoyan V, Thiel A, Thoma U, Urban M, van Pee H, Walther D, Wendel C, Wiedner U, Wilson A, Winnebeck A. First measurement of the helicity asymmetry for γp → pπ0 in the resonance region. Phys Rev Lett 2014; 112:012003. [PMID: 24483889 DOI: 10.1103/physrevlett.112.012003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Indexed: 06/03/2023]
Abstract
The first measurement of the helicity dependence of the photoproduction cross section of single neutral pions off protons is reported for photon energies from 600 to 2300 MeV, covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between data and predictions are observed, which are traced to differences in the helicity amplitudes of well-known and established resonances. Precise values for the helicity amplitudes of several resonances are reported.
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Affiliation(s)
- M Gottschall
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A V Anisovich
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - B Bantes
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - D Bayadilov
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - R Beck
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Bichow
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - S Böse
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K-Th Brinkmann
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - Th Challand
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - V Crede
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - F Dietz
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - H Dutz
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - H Eberhardt
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - D Elsner
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - R Ewald
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - K Fornet-Ponse
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - St Friedrich
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - F Frommberger
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ch Funke
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Gridnev
- Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - M Grüner
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - E Gutz
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - Ch Hammann
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - J Hannappel
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - J Hartmann
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - W Hillert
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - Ph Hoffmeister
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Honisch
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Jaegle
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - D Kaiser
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Kalinowsky
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - S Kammer
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - I Keshelashvili
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - F Klein
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - E Klempt
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - K Koop
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - B Krusche
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - M Kube
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Lang
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - I Lopatin
- Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - Y Maghrbi
- Department Physik, Universität Basel, 4056 Basel, Switzerland
| | - K Makonyi
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Metag
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - W Meyer
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - J Müller
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Nanova
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - V Nikonov
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - R Novotny
- II. Physikalisches Institut, Universität Gießen, 35392 Gießen, Germany
| | - D Piontek
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - G Reicherz
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - T Rostomyan
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Sarantsev
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany and Petersburg Nuclear Physics Institute, Gatchina, 188300 Russia
| | - St Schaepe
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Schmidt
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H Schmieden
- Physikalisches Institut, Universität Bonn, 53115 Bonn, Germany
| | - R Schmitz
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - T Seifen
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - V Sokhoyan
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - A Thiel
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Thoma
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - M Urban
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - H van Pee
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - D Walther
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - Ch Wendel
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
| | - U Wiedner
- Institut für Experimentalphysik I, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - A Wilson
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - A Winnebeck
- Helmholtz-Institut für Strahlen-und Kernphysik, Universität Bonn, 53115 Bonn, Germany
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18
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Werthmüller D, Witthauer L, Keshelashvili I, Aguar-Bartolomé P, Ahrens J, Annand JRM, Arends HJ, Bantawa K, Beck R, Bekrenev V, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Demissie B, Dieterle M, Downie EJ, Drexler P, Fil'kov LV, Fix A, Glazier DI, Hamilton D, Heid E, Hornidge D, Howdle D, Huber GM, Jaegle I, Jahn O, Jude TC, Käser A, Kashevarov VL, Kondratiev R, Korolija M, Kruglov SP, Krusche B, Kulbardis A, Lisin V, Livingston K, MacGregor IJD, Maghrbi Y, Mancell J, Manley DM, Marinides Z, Martinez M, McGeorge JC, McNicoll EF, Metag V, Middleton DG, Mushkarenkov A, Nefkens BMK, Nikolaev A, Novotny R, Oberle M, Ostrick M, Oussena B, Pedroni P, Pheron F, Polonski A, Prakhov SN, Robinson J, Rosner G, Rostomyan T, Schumann S, Sikora MH, Sober D, Starostin A, Supek I, Thiel M, Thomas A, Unverzagt M, Watts DP. Narrow structure in the excitation function of η photoproduction off the neutron. Phys Rev Lett 2013; 111:232001. [PMID: 24476257 DOI: 10.1103/physrevlett.111.232001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 10/28/2013] [Indexed: 06/03/2023]
Abstract
The photoproduction of η mesons off nucleons bound in 2H and 3He has been measured in coincidence with recoil protons and recoil neutrons for incident photon energies from threshold up to 1.4 GeV. The experiments were performed at the Mainz MAMI accelerator, using the Glasgow tagged photon facility. Decay photons from the η→2γ and η→3π0 decays and the recoil nucleons were detected with an almost 4π electromagnetic calorimeter combining the Crystal Ball and TAPS detectors. The data from both targets are of excellent statistical quality and show a narrow structure in the excitation function of γn→nη. The results from the two measurements are consistent, taking into account the expected effects from nuclear Fermi motion. The best estimates for position and intrinsic width of the structure are W=(1670±5) MeV and Γ=(30±15) MeV. For the first time precise results for the angular dependence of this structure have been extracted.
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Affiliation(s)
- D Werthmüller
- Departement für Physik, Universität Basel, Switzerland
| | - L Witthauer
- Departement für Physik, Universität Basel, Switzerland
| | | | | | - J Ahrens
- Institut für Kernphysik, Universität Mainz, Germany
| | - J R M Annand
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - H J Arends
- Institut für Kernphysik, Universität Mainz, Germany
| | - K Bantawa
- Kent State University, Kent, Ohio, USA
| | - R Beck
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - V Bekrenev
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | | | - D Branford
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - W J Briscoe
- Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - J Brudvik
- University of California at Los Angeles, Los Angeles, California, USA
| | | | - B Demissie
- Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - M Dieterle
- Departement für Physik, Universität Basel, Switzerland
| | - E J Downie
- Institut für Kernphysik, Universität Mainz, Germany and SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom and Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - P Drexler
- II. Physikalisches Institut, Universität Giessen, Germany
| | | | - A Fix
- Laboratory of Mathematical Physics, Tomsk Polytechnic University, Tomsk, Russia
| | - D I Glazier
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Hamilton
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E Heid
- Institut für Kernphysik, Universität Mainz, Germany
| | - D Hornidge
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | - D Howdle
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G M Huber
- University of Regina, Regina, SK S4S 0A2, Canada
| | - I Jaegle
- Departement für Physik, Universität Basel, Switzerland
| | - O Jahn
- Institut für Kernphysik, Universität Mainz, Germany
| | - T C Jude
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - A Käser
- Departement für Physik, Universität Basel, Switzerland
| | - V L Kashevarov
- Institut für Kernphysik, Universität Mainz, Germany and Lebedev Physical Institute, Moscow, Russia
| | | | - M Korolija
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - S P Kruglov
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - B Krusche
- Departement für Physik, Universität Basel, Switzerland
| | - A Kulbardis
- Petersburg Nuclear Physics Institute, Gatchina, Russia
| | - V Lisin
- Institute for Nuclear Research, Moscow, Russia
| | - K Livingston
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - I J D MacGregor
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Y Maghrbi
- Departement für Physik, Universität Basel, Switzerland
| | - J Mancell
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - Z Marinides
- Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | - M Martinez
- Institut für Kernphysik, Universität Mainz, Germany
| | - J C McGeorge
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - E F McNicoll
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - V Metag
- II. Physikalisches Institut, Universität Giessen, Germany
| | - D G Middleton
- Mount Allison University, Sackville, New Brunswick E4L 1E6, Canada
| | | | - B M K Nefkens
- University of California at Los Angeles, Los Angeles, California, USA
| | - A Nikolaev
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - R Novotny
- II. Physikalisches Institut, Universität Giessen, Germany
| | - M Oberle
- Departement für Physik, Universität Basel, Switzerland
| | - M Ostrick
- Institut für Kernphysik, Universität Mainz, Germany
| | - B Oussena
- Institut für Kernphysik, Universität Mainz, Germany and Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA
| | | | - F Pheron
- Departement für Physik, Universität Basel, Switzerland
| | - A Polonski
- Institute for Nuclear Research, Moscow, Russia
| | - S N Prakhov
- Institut für Kernphysik, Universität Mainz, Germany and Institute for Nuclear Studies, The George Washington University, Washington, District of Columbia, USA and University of California at Los Angeles, Los Angeles, California, USA
| | - J Robinson
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - G Rosner
- SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - T Rostomyan
- Departement für Physik, Universität Basel, Switzerland
| | - S Schumann
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - M H Sikora
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - D Sober
- The Catholic University of America, Washington, District of Columbia, USA
| | - A Starostin
- University of California at Los Angeles, Los Angeles, California, USA
| | - I Supek
- Rudjer Boskovic Institute, Zagreb, Croatia
| | - M Thiel
- Institut für Kernphysik, Universität Mainz, Germany and II. Physikalisches Institut, Universität Giessen, Germany
| | - A Thomas
- Institut für Kernphysik, Universität Mainz, Germany
| | - M Unverzagt
- Institut für Kernphysik, Universität Mainz, Germany and Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, Germany
| | - D P Watts
- SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
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19
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Hornidge D, Aguar Bartolomé P, Annand JRM, Arends HJ, Beck R, Bekrenev V, Berghäuser H, Bernstein AM, Braghieri A, Briscoe WJ, Cherepnya S, Dieterle M, Downie EJ, Drexler P, Fernández-Ramírez C, Filkov LV, Glazier DI, Hall Barrientos P, Heid E, Hilt M, Jaegle I, Jahn O, Jude TC, Kashevarov VL, Keshelashvili I, Kondratiev R, Korolija M, Koulbardis A, Krambrich D, Kruglov S, Krusche B, Laffoley AT, Lisin V, Livingston K, MacGregor IJD, Mancell J, Manley DM, McNicoll EF, Mekterovic D, Metag V, Micanovic S, Middleton DG, Moores KW, Mushkarenkov A, Nefkens BMK, Oberle M, Ostrick M, Otte PB, Oussena B, Pedroni P, Pheron F, Polonski A, Prakhov S, Robinson J, Rostomyan T, Scherer S, Schumann S, Sikora MH, Starostin A, Supek I, Thiel M, Thomas A, Tiator L, Unverzagt M, Watts DP, Werthmüller D, Witthauer L. Accurate test of chiral dynamics in the γp→π0p reaction. Phys Rev Lett 2013; 111:062004. [PMID: 23971564 DOI: 10.1103/physrevlett.111.062004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Indexed: 06/02/2023]
Abstract
A precision measurement of the differential cross sections dσ/dΩ and the linearly polarized photon asymmetry Σ≡(dσ⊥-dσ∥)/(dσ⊥+dσ∥) for the γp→π0p reaction in the near-threshold region has been performed with a tagged photon beam and almost 4π detector at the Mainz Microtron. The Glasgow-Mainz photon tagging facility along with the Crystal Ball/TAPS multiphoton detector system and a cryogenic liquid hydrogen target were used. These data allowed for a precise determination of the energy dependence of the real parts of the S- and all three P-wave amplitudes for the first time and provide the most stringent test to date of the predictions of chiral perturbation theory and its energy region of agreement with experiment.
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Affiliation(s)
- D Hornidge
- Mount Allison University, Sackville, New Brunswick, E4L 1E6, Canada.
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20
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Krambrich D, Zehr F, Fix A, Roca L, Aguar P, Ahrens J, Annand JRM, Arends HJ, Beck R, Bekrenev V, Boillat B, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Codling R, Downie EJ, Dexler P, Glazier DI, Grabmayr P, Gregor R, Heid E, Hornidge D, Jahn O, Kashevarov VL, Knezevic A, Kondratiev R, Korolija M, Kotulla M, Krusche B, Kulbardis A, Lang M, Lisin V, Livingston K, Lugert S, MacGregor IJD, Manley DM, Martinez M, McGeorge JC, Mekterovic D, Metag V, Nefkens BMK, Nikolaev A, Pedroni P, Pheron F, Polonski A, Prakhov SN, Price JW, Rosner G, Rost M, Rostomyan T, Schumann S, Sober D, Starostin A, Supek I, Tarbert CM, Thomas A, Unverzagt M, Walcher T, Watts DP. Beam-helicity asymmetries in double-pion photoproduction off the proton. Phys Rev Lett 2009; 103:052002. [PMID: 19792489 DOI: 10.1103/physrevlett.103.052002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 06/18/2009] [Indexed: 05/28/2023]
Abstract
Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz in the three isospin channels gamma[over -->]p-->pi(+)pi(0)n, gamma[over -->]p-->pi(0)pi(0)p, and gamma[over -->]p-->pi(+)pi(-)p. The circularly polarized photons, produced from bremsstrahlung of longitudinally polarized electrons, were tagged with the Glasgow magnetic spectrometer. Charged pions and the decay photons of pi(0) mesons were detected in a 4pi electromagnetic calorimeter which combined the Crystal Ball detector with the TAPS detector. The precisely measured asymmetries are very sensitive to details of the production processes and are thus key observables in the modeling of the reaction dynamics.
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Affiliation(s)
- D Krambrich
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, Mainz, Germany
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21
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Tarbert CM, Watts DP, Aguar P, Ahrens J, Annand JRM, Arends HJ, Beck R, Bekrenev V, Boillat B, Braghieri A, Branford D, Briscoe WJ, Brudvik J, Cherepnya S, Codling R, Downie EJ, Föhl K, Glazier DI, Grabmayr P, Gregor R, Heid E, Hornidge D, Jahn O, Kashevarov VL, Knezevic A, Kondratiev R, Korolija M, Kotulla M, Krambrich D, Krusche B, Lang M, Lisin V, Livingston K, Lugert S, Macgregor IJD, Manley DM, Martinez M, McGeorge JC, Mekterovic D, Metag V, Nefkens BMK, Nikolaev A, Novotny R, Owens RO, Pedroni P, Polonski A, Prakhov SN, Price JW, Rosner G, Rost M, Rostomyan T, Schadmand S, Schumann S, Sober D, Starostin A, Supek I, Thomas A, Unverzagt M, Walcher T, Zehr F. Incoherent neutral pion photoproduction on 12C. Phys Rev Lett 2008; 100:132301. [PMID: 18517938 DOI: 10.1103/physrevlett.100.132301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Indexed: 05/26/2023]
Abstract
We present the first detailed measurement of incoherent photoproduction of neutral pions to a discrete state of a residual nucleus. The 12C(gamma,pi(0))(12)C*(4.4 MeV) reaction has been studied with the Glasgow photon tagger at MAMI employing a new technique which uses the large solid angle Crystal Ball detector both as a pi(0) spectrometer and to detect decay photons from the excited residual nucleus. The technique has potential applications to a broad range of future nuclear measurements with the Crystal Ball and similar detector systems elsewhere. Such data are sensitive to the propagation of the Delta in the nuclear medium and will give the first information on matter transition form factors from measurements with an electromagnetic probe. The incoherent cross sections are compared to two theoretical predictions including a Delta-hole model.
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Affiliation(s)
- C M Tarbert
- School of Physics, University of Edinburgh, Edinburgh, United Kingdom
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22
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Ahrens J, Altieri S, Annand JRM, Arends HJ, Beck R, Bradtke C, Braghieri A, d'Hose N, Dutz H, Goertz S, Grabmayr P, Hasegawa S, Heid E, Holvoet H, Van Hoorebeke L, Horikawa N, Iwata T, Jahn O, Jennewein P, Klein F, Kondratiev R, Lang M, Lannoy B, Lisin V, Martinez-Fabregate M, McGeorge JC, Meyer W, Panzeri A, Pedroni P, Pinelli T, Preobrajenski I, Reicherz G, Rohlof C, Rosner G, Rost M, Rostomyan T, Ryckbosch D, Schumacher M, Seitz B, Tamas G, Thomas A, Van de Vyver R, Zapadtka F. Measurement of the Gerasimov-Drell-Hearn Integrand for 2H from 200 to 800 MeV. Phys Rev Lett 2006; 97:202303. [PMID: 17155680 DOI: 10.1103/physrevlett.97.202303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Indexed: 05/12/2023]
Abstract
A measurement of the helicity dependence of the total inclusive photoabsorption cross section on the deuteron was carried out at MAMI (Mainz) in the energy range 200<Egamma<800 MeV. The experiment used a 4pi detection system, a circularly polarized tagged photon beam and a frozen-spin target which provided longitudinally polarized deuterons. The contribution to the Gerasimov-Drell-Hearn sum rule for the deuteron determined from the data is 407+/-20(stat)+/-24(syst) mu b for 200<Egamma<800 MeV.
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Affiliation(s)
- J Ahrens
- Institut für Kernphysik, Universität Mainz, D-55099 Mainz, Germany
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23
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Dutz H, Helbing K, Krimmer J, Speckner T, Zeitler G, Ahrens J, Altieri S, Annand JRM, Anton G, Arends HJ, Beck R, Bock A, Bradtke C, Braghieri A, v Drachenfels W, Frommberger F, Godo M, Goertz S, Grabmayr P, Hasegawa S, Hansen K, Harmsen J, Heid E, Hillert W, Holvoet H, Horikawa N, Iwata T, Van Hoorebeke L, d'Hose N, Jennewein P, Kiel B, Klein F, Kondratiev R, Lang M, Lannoy B, Leukel R, Lisin V, Menze D, Meyer W, Michel T, Naumann J, Panzeri A, Pedroni P, Pinelli T, Preobrajenski I, Radtke E, Reicherz G, Rohlof C, Rostomyan T, Sauer M, Schoch B, Schumacher M, Tamas G, Thomas A, van de Vyver R, Weihofen W, Zapadtka F. Measurement of helicity-dependent photoabsorption cross sections on the neutron from 815 to 1825 MeV. Phys Rev Lett 2005; 94:162001. [PMID: 15904214 DOI: 10.1103/physrevlett.94.162001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Indexed: 05/02/2023]
Abstract
Helicity-dependent total photoabsorption cross sections on the deuteron have been measured for the first time at ELSA (Bonn) in the photon energy range from 815 to 1825 MeV. Circularly polarized tagged photons impinging on a longitudinally polarized LiD target have been used together with a highly efficient 4pi detector system. The data around 1 GeV are not compatible with predictions from existing multipole analyses. From the measured energy range an experimental contribution to the GDH integral on the neutron of [33.9 +/- 5.5(stat) +/- 4.5(syst)] microb is extracted.
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Affiliation(s)
- H Dutz
- Physikalisches Institut, Universität Bonn, D-53115 Bonn, Germany
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24
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Dutz H, Helbing K, Krimmer J, Speckner T, Zeitler G, Ahrens J, Altieri S, Annand JRM, Anton G, Arends HJ, Beck R, Bock A, Bradtke C, Braghieri A, v Drachenfels W, Frommberger F, Godo M, Goertz S, Grabmayr P, Hasegawa S, Hansen K, Harmsen J, Heid E, Hillert W, Holvoet H, Horikawa N, Iwata T, Hoorebeke LV, D'Hose N, Jennewein P, Kiel B, Klein F, Kondratiev R, Lang M, Lannoy B, Leukel R, Lisin V, Menze D, Meyer W, Michel T, Naumann J, Panzeri A, Pedroni P, Pinelli T, Preobrajenski I, Radtke E, Reicherz G, Rohlof C, Rostomyan T, Sauer M, Schoch B, Schumacher M, Tamas G, Thomas A, van de Vyver R, Weihofen W, Zapadtka F. Experimental check of the Gerasimov-Drell-Hearn sum rule for 1H. Phys Rev Lett 2004; 93:032003. [PMID: 15323817 DOI: 10.1103/physrevlett.93.032003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2004] [Indexed: 05/24/2023]
Abstract
For the first time we checked the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the proton experimentally in the photon energy range from 0.2-2.9 GeV with the tagged photon facilities at MAMI (Mainz) and ELSA (Bonn). New data of the doubly polarized total cross section difference are presented in the energy range from 1.6 to 2.9 GeV. The contribution to the GDH integral from 0.2-2.9 GeV yields [254+/-5(stat)+/-12(syst)] microb with negative contributions in the Regge regime at photon energies above 2.1 GeV. This trend supports the validity of the GDH sum rule.
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Affiliation(s)
- H Dutz
- Physikalisches Institut, Universität Bonn, D-53115 Bonn, Germany
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25
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Dutz H, Helbing K, Krimmer J, Speckner T, Zeitler G, Ahrens J, Altieri S, Annand JRM, Anton G, Arends HJ, Beck R, Bock A, Bradtke C, Braghieri A, v Drachenfels W, Frommberger F, Godo M, Goertz S, Grabmayr P, Hasegawa S, Hansen K, Harmsen J, Heid E, Hillert W, Holvoet H, Horikawa N, Iwata T, Van Hoorebeke L, d'Hose N, Jennewein P, Kiel B, Klein F, Kondratiev R, Lang M, Lannoy B, Leukel R, Lisin V, Menze D, Meyer W, Michel T, Naumann J, Panzeri A, Pedroni P, Pinelli T, Preobrajenski I, Radtke E, Reicherz G, Rohlof C, Rostomyan T, Sauer M, Schoch B, Schumacher M, Tamas G, Thomas A, van de Vyver R, Weihofen W, Zapadtka F. First Measurement of the Gerasimov-Drell-Hearn Sum Rule for 1H from 0.7 to 1.8 GeV at ELSA. Phys Rev Lett 2003; 91:192001. [PMID: 14611575 DOI: 10.1103/physrevlett.91.192001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2003] [Indexed: 05/24/2023]
Abstract
To verify the fundamental Gerasimov-Drell-Hearn (GDH) sum rule for the first time experimentally, we measured the helicity dependent total photoabsorption cross section with circularly polarized real photons and longitudinally polarized nucleons in the photon energy range 0.68-1.82 GeV with the tagged photon facility at ELSA. The experiment was carried out with a 4pi detection system, a circularly polarized tagged photon beam, and a frozen spin polarized proton target. The contribution to the GDH sum rule in this photon energy range is [49.9+/-2.4(stat)+/-2.2(syst)] microb.
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Affiliation(s)
- H Dutz
- Physikalisches Institut, Universität Bonn, D-53115 Bonn, Germany
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