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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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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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Li X, Ahmed MW, Banu A, Bartram C, Crowe B, Downie EJ, Emamian M, Feldman G, Gao H, Godagama D, Grießhammer HW, Howell CR, Karwowski HJ, Kendellen DP, Kovash MA, Leung KKH, Markoff DM, McGovern JA, Mikhailov S, Pywell RE, Sikora MH, Silano JA, Sosa RS, Spraker MC, Swift G, Wallace P, Weller HR, Whisnant CS, Wu YK, Zhao ZW. Proton Compton Scattering from Linearly Polarized Gamma Rays. Phys Rev Lett 2022; 128:132502. [PMID: 35426711 DOI: 10.1103/physrevlett.128.132502] [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: 08/13/2021] [Revised: 12/14/2021] [Accepted: 03/18/2022] [Indexed: 06/14/2023]
Abstract
Differential cross sections for Compton scattering from the proton have been measured at scattering angles of 55°, 90°, and 125° in the laboratory frame using quasimonoenergetic linearly (circularly) polarized photon beams with a weighted mean energy value of 83.4 MeV (81.3 MeV). These measurements were performed at the High Intensity Gamma-Ray Source facility at the Triangle Universities Nuclear Laboratory. The results are compared to previous measurements and are interpreted in the chiral effective field theory framework to extract the electromagnetic dipole polarizabilities of the proton, which gives α_{E1}^{p}=13.8±1.2_{stat}±0.1_{BSR}±0.3_{theo},β_{M1}^{p}=0.2∓1.2_{stat}±0.1_{BSR}∓0.3_{theo} in units of 10^{-4} fm^{3}.
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Affiliation(s)
- X Li
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - M W Ahmed
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- Department of Mathematics and Physics, North Carolina Central University, Durham, North Carolina, 27707, USA
| | - A Banu
- Department of Physics and Astronomy, James Madison University, Harrisonburg, Virginia 22807, USA
| | - C Bartram
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516, USA
| | - B Crowe
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- Department of Mathematics and Physics, North Carolina Central University, Durham, North Carolina, 27707, USA
| | - E J Downie
- Institute for Nuclear Studies, Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - M Emamian
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - G Feldman
- Institute for Nuclear Studies, Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - H Gao
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - D Godagama
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA
| | - H W Grießhammer
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Institute for Nuclear Studies, Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - C R Howell
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - H J Karwowski
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516, USA
| | - D P Kendellen
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - M A Kovash
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA
| | - K K H Leung
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- Department of Physics and Astronomy, Montclair State University, Montclair, New Jersey 07043, USA
| | - D M Markoff
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- Department of Mathematics and Physics, North Carolina Central University, Durham, North Carolina, 27707, USA
| | - J A McGovern
- Theoretical Physics Group, Department of Physics and Astronomy, University of Manchester, Manchester M13 9PL, United Kingdom
| | - S Mikhailov
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - R E Pywell
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - M H Sikora
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- Institute for Nuclear Studies, Department of Physics, The George Washington University, Washington, D.C. 20052, USA
| | - J A Silano
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516, USA
| | - R S Sosa
- Department of Mathematics and Physics, North Carolina Central University, Durham, North Carolina, 27707, USA
| | - M C Spraker
- Department of Physics and Astronomy, University of North Georgia, Dahlonega, Georgia 30597, USA
| | - G Swift
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - P Wallace
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - H R Weller
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - C S Whisnant
- Department of Physics and Astronomy, James Madison University, Harrisonburg, Virginia 22807, USA
| | - Y K Wu
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
| | - Z W Zhao
- Department of Physics, Duke University, Durham, North Carolina 27708-0308, USA
- Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708-0308, USA
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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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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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6
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Bashkanov M, Watts DP, Kay SJD, Abt S, Achenbach P, Adlarson P, Afzal F, Ahmed Z, Akondi CS, Annand JRM, Arends HJ, Beck R, Biroth M, Borisov N, Braghieri A, Briscoe WJ, Cividini F, Collicott C, Costanza S, Denig A, Downie EJ, Drexler P, Fegan S, Fix A, Gardner S, Ghosal D, Glazier DI, Gorodnov I, Gradl W, Günther M, Gurevich D, Heijkenskjöld L, Hornidge D, Huber GM, Käser A, Kashevarov VL, Korolija M, Krusche B, Lazarev A, Livingston K, Lutterer S, MacGregor IJD, Manley DM, Martel PP, Miskimen R, Mornacchi E, Mullen C, Neganov A, Neiser A, Ostrick M, Otte PB, Paudyal D, Pedroni P, Powell A, Prakhov SN, Ron G, Sarty A, Sfienti C, Sokhoyan V, Spieker K, Steffen O, Strakovsky II, Strub T, Supek I, Thiel A, Thiel M, Thomas A, Usov YA, Wagner S, Walford NK, Werthmüller D, Wettig J, Wolfes M, Zachariou N, Zana LA. Signatures of the d^{*}(2380) Hexaquark in d(γ,pn[over →]). Phys Rev Lett 2020; 124:132001. [PMID: 32302204 DOI: 10.1103/physrevlett.124.132001] [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: 11/19/2019] [Revised: 01/30/2020] [Accepted: 03/02/2020] [Indexed: 06/11/2023]
Abstract
We report a measurement of the spin polarization of the recoiling neutron in deuterium photodisintegration, utilizing a new large acceptance polarimeter within the Crystal Ball at MAMI. The measured photon energy range of 300-700 MeV provides the first measurement of recoil neutron polarization at photon energies where the quark substructure of the deuteron plays a role, thereby providing important new constraints on photodisintegration mechanisms. A very high neutron polarization in a narrow structure centered around E_{γ}∼570 MeV is observed, which is inconsistent with current theoretical predictions employing nucleon resonance degrees of freedom. A Legendre polynomial decomposition suggests this behavior could be related to the excitation of the d^{*}(2380) hexaquark.
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Affiliation(s)
- M Bashkanov
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - D P Watts
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
| | - S J D Kay
- University of Regina, Regina, SK S4S0A2 Canada
| | - 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
| | - 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
| | - 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
- Dipartimento di Fisica, Università di Pavia, I-27100 Pavia, Italy
| | - A Denig
- Institut für Kernphysik, University of Mainz, D-55099 Mainz, Germany
| | - 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
| | - A Fix
- Tomsk Polytechnic University, 634034 Tomsk, Russia
| | - 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
| | - 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, SK S4S0A2 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
| | - 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
| | - 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
| | - 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 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
| | - S N Prakhov
- University of California Los Angeles, Los Angeles, California 90095-1547, USA
| | - G Ron
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - 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
| | - 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 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
| | - 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
| | - L A Zana
- Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA
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7
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Beričič J, Correa L, Benali M, Achenbach P, Ayerbe Gayoso C, Bernauer JC, Blomberg A, Böhm R, Bosnar D, Debenjak L, Denig A, Distler MO, Downie EJ, Esser A, Fonvieille H, Friščić I, Kegel S, Kohl Y, Makek M, Merkel H, Middleton DG, Mihovilovič M, Müller U, Nungesser L, Paolone M, Pochodzalla J, Sánchez Majos S, Schlimme BS, Schoth M, Schulz F, Sfienti C, Širca S, Sparveris N, Štajner S, Thiel M, Tyukin A, Weber A, Weinriefer M. New Insight in the Q^{2} Dependence of Proton Generalized Polarizabilities. Phys Rev Lett 2019; 123:192302. [PMID: 31765208 DOI: 10.1103/physrevlett.123.192302] [Citation(s) in RCA: 2] [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: 07/24/2019] [Revised: 10/04/2019] [Indexed: 06/10/2023]
Abstract
Virtual Compton scattering on the proton has been investigated at three yet unexplored values of the four-momentum transfer Q^{2}: 0.10, 0.20, and 0.45 GeV^{2}, at the Mainz Microtron. Fits performed using either the low-energy theorem or dispersion relations allowed the extraction of the structure functions P_{LL}-P_{TT}/ε and P_{LT}, as well as the electric and magnetic generalized polarizabilities α_{E1}(Q^{2}) and β_{M1}(Q^{2}). These new results show a smooth and rapid falloff of α_{E1}(Q^{2}), in contrast to previous measurements at Q^{2}=0.33 GeV^{2}, and provide for the first time a precise mapping of β_{M1}(Q^{2}) in the low-Q^{2} region.
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Affiliation(s)
- J Beričič
- Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - L Correa
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000 Clermont-Ferrand, France
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Benali
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000 Clermont-Ferrand, France
| | - P Achenbach
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Ayerbe Gayoso
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - J C Bernauer
- Department of Physics and Astronomy, Stony Brook University, SUNY, Stony Brook, New York 11794-3800, USA
- RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - A Blomberg
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - R Böhm
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D Bosnar
- Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - L Debenjak
- Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - A Denig
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M O Distler
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - E J Downie
- Institute for Nuclear Studies, Department of Physics, The George Washington University, Washington, DC 20052, USA
| | - A Esser
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - H Fonvieille
- Université Clermont Auvergne, CNRS/IN2P3, LPC, F-63000 Clermont-Ferrand, France
| | - I Friščić
- Laboratory for Nuclear Science, Massachussetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - S Kegel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - Y Kohl
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Makek
- Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - H Merkel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - D G Middleton
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Mihovilovič
- Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - U Müller
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - L Nungesser
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Paolone
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - J Pochodzalla
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Sánchez Majos
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - B S Schlimme
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Schoth
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - F Schulz
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - C Sfienti
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - S Širca
- Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - N Sparveris
- Temple University, Philadelphia, Pennsylvania 19122, USA
| | - S Štajner
- Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - M Thiel
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Tyukin
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - A Weber
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
| | - M Weinriefer
- Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany
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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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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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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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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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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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14
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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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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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18
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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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19
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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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20
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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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21
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Evison L, Downie EJ. Nurse-midwifery prototypes: clinical practice and education featuring Cook County Hospital Nurse-Midwifery Service. J Nurse Midwifery 1978; 23:27-30. [PMID: 249777 DOI: 10.1016/0091-2182(78)90025-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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