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Gray TJ, Allmond JM, Xu Z, King TT, Lubna RS, Crawford HL, Tripathi V, Crider BP, Grzywacz R, Liddick SN, Macchiavelli AO, Miyagi T, Poves A, Andalib A, Argo E, Benetti C, Bhattacharya S, Campbell CM, Carpenter MP, Chan J, Chester A, Christie J, Clark BR, Cox I, Doetsch AA, Dopfer J, Duarte JG, Fallon P, Frotscher A, Gaballah T, Harke JT, Heideman J, Huegen H, Holt JD, Jain R, Kitamura N, Kolos K, Kondev FG, Laminack A, Longfellow B, Luitel S, Madurga M, Mahajan R, Mogannam MJ, Morse C, Neupane S, Nowicki A, Ogunbeku TH, Ong WJ, Porzio C, Prokop CJ, Rasco BC, Ronning EK, Rubino E, Ruland TJ, Rykaczewski KP, Schaedig L, Seweryniak D, Siegl K, Singh M, Stuchbery AE, Tabor SL, Tang TL, Wheeler T, Winger JA, Wood JL. Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB. Phys Rev Lett 2023; 130:242501. [PMID: 37390416 DOI: 10.1103/physrevlett.130.242501] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/26/2023] [Indexed: 07/02/2023]
Abstract
Excited-state spectroscopy from the first experiment at the Facility for Rare Isotope Beams (FRIB) is reported. A 24(2)-μs isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV γ rays in coincidence with ^{32}Na nuclei. This is the only known microsecond isomer (1 μs≤T_{1/2}<1 ms) in the region. This nucleus is at the heart of the N=20 island of shape inversion and is at the crossroads of the spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to ^{32}Mg, ^{32}Mg+π^{-1}+ν^{+1}. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of ^{32}Mg, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed 2^{+} state at 885 keV and a low-lying shape-coexisting 0_{2}^{+} state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in ^{32}Na: a 6^{-} spherical shape isomer that decays by E2 or a 0^{+} deformed spin isomer that decays by M2. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.
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Affiliation(s)
- T J Gray
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - J M Allmond
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Z Xu
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T T King
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - R S Lubna
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - V Tripathi
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - B P Crider
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - R Grzywacz
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - S N Liddick
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - A O Macchiavelli
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - T Miyagi
- Department of Physics, Technische Universität Darmstadt, Darmstadt, Germany
- ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
| | - A Poves
- Departamento de Fìsica Teórica and IFT-UAM/CSIC, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - A Andalib
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Argo
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Benetti
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - S Bhattacharya
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chan
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Chester
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Christie
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - B R Clark
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - I Cox
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A A Doetsch
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J Dopfer
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J G Duarte
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Frotscher
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - T Gaballah
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - J T Harke
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J Heideman
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - H Huegen
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - J D Holt
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Physics, McGill University, Montréal, Quebec City H3A 2T8, Canada
| | - R Jain
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - N Kitamura
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - K Kolos
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Laminack
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - B Longfellow
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Luitel
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - M Madurga
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - R Mahajan
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - M J Mogannam
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - C Morse
- National Nuclear Data Center, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - S Neupane
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A Nowicki
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - T H Ogunbeku
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - W-J Ong
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Porzio
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C J Prokop
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - B C Rasco
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - E K Ronning
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
| | - E Rubino
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - T J Ruland
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
| | - K P Rykaczewski
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - L Schaedig
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - K Siegl
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - M Singh
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37966, USA
| | - A E Stuchbery
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, Australian National University, Canberra, Australian Capital Territory, 2601, Australia
| | - S L Tabor
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T L Tang
- Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
| | - T Wheeler
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - J A Winger
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, Mississippi 39762, USA
| | - J L Wood
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA
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Kay BP, Tang TL, Tolstukhin IA, Roderick GB, Mitchell AJ, Ayyad Y, Bennett SA, Chen J, Chipps KA, Crawford HL, Freeman SJ, Garrett K, Gott MD, Hall MR, Hoffman CR, Jayatissa H, Macchiavelli AO, MacGregor PT, Sharp DK, Wilson GL. Quenching of Single-Particle Strength in A=15 Nuclei. Phys Rev Lett 2022; 129:152501. [PMID: 36269970 DOI: 10.1103/physrevlett.129.152501] [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: 02/06/2022] [Revised: 07/05/2022] [Accepted: 08/29/2022] [Indexed: 06/16/2023]
Abstract
Absolute cross sections for the addition of s- and d-wave neutrons to ^{14}C and ^{14}N have been determined simultaneously via the (d,p) reaction at 10 MeV/u. The difference between the neutron and proton separation energies, ΔS, is around -20 MeV for the ^{14}C+n system and +8 MeV for ^{14}N+n. The population of the 1s_{1/2} and 0d_{5/2} orbitals for both systems is reduced by a factor of approximately 0.5 compared with the independent single-particle model, or about 0.6 when compared with the shell model. This finding strongly contrasts with results deduced from intermediate-energy knockout reactions between similar nuclei on targets of ^{9}Be and ^{12}C. The simultaneous technique used removes many systematic uncertainties.
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Affiliation(s)
- B P Kay
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - T L Tang
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - I A Tolstukhin
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - G B Roderick
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, The Australian National University, Canberra ACT 2601, Australia
| | - A J Mitchell
- Department of Nuclear Physics and Accelerator Applications, Research School of Physics, The Australian National University, Canberra ACT 2601, Australia
| | - Y Ayyad
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - S A Bennett
- Schuster Laboratory, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - J Chen
- Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824, USA
| | - K A Chipps
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S J Freeman
- Schuster Laboratory, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - K Garrett
- Schuster Laboratory, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - M D Gott
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - M R Hall
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - C R Hoffman
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - H Jayatissa
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P T MacGregor
- Schuster Laboratory, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - D K Sharp
- Schuster Laboratory, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - G L Wilson
- Physics Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Pore JL, Gates JM, Orford R, Campbell CM, Clark RM, Crawford HL, Esker NE, Fallon P, Gooding JA, Kwarsick JT, Macchiavelli AO, Morse C, Rudolph D, Såmark-Roth A, Santamaria C, Shah RS, Stoyer MA. Identification of the New Isotope ^{244}Md. Phys Rev Lett 2020; 124:252502. [PMID: 32639781 DOI: 10.1103/physrevlett.124.252502] [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: 01/31/2020] [Revised: 04/10/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
In an experiment performed at Lawrence Berkeley National Laboratory's 88-inch cyclotron, the isotope ^{244}Md was produced in the ^{209}Bi(^{40}Ar,5n) reaction. Decay properties of ^{244}Md were measured at the focal plane of the Berkeley Gas-filled Separator, and the mass number assignment of A=244 was confirmed with the apparatus for the identification of nuclide A. The isotope ^{244}Md is reported to have one, possibly two, α-decaying states with α energies of 8.66(2) and 8.31(2) MeV and half-lives of 0.4_{-0.1}^{+0.4} and ∼6 s, respectively. Additionally, first evidence of the α decay of ^{236}Bk was observed and is reported.
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Affiliation(s)
- J L Pore
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - J M Gates
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - R Orford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - R M Clark
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - N E Esker
- Department of Chemistry, San José State University, One Washington Square, San José, California 95192, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - J A Gooding
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
- Department of Physics, Lund University, SE-22100 Lund, Sweden
| | - J T Kwarsick
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - C Morse
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - D Rudolph
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, USA
| | - A Såmark-Roth
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, USA
| | - C Santamaria
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
| | - R S Shah
- Department of Physics, Lund University, SE-22100 Lund, Sweden
| | - M A Stoyer
- Nuclear Science Division, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550, USA
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Bagchi S, Kanungo R, Tanaka YK, Geissel H, Doornenbal P, Horiuchi W, Hagen G, Suzuki T, Tsunoda N, Ahn DS, Baba H, Behr K, Browne F, Chen S, Cortés ML, Estradé A, Fukuda N, Holl M, Itahashi K, Iwasa N, Jansen GR, Jiang WG, Kaur S, Macchiavelli AO, Matsumoto SY, Momiyama S, Murray I, Nakamura T, Novario SJ, Ong HJ, Otsuka T, Papenbrock T, Paschalis S, Prochazka A, Scheidenberger C, Schrock P, Shimizu Y, Steppenbeck D, Sakurai H, Suzuki D, Suzuki H, Takechi M, Takeda H, Takeuchi S, Taniuchi R, Wimmer K, Yoshida K. Two-Neutron Halo is Unveiled in ^{29}F. Phys Rev Lett 2020; 124:222504. [PMID: 32567915 DOI: 10.1103/physrevlett.124.222504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/17/2020] [Accepted: 05/08/2020] [Indexed: 06/11/2023]
Abstract
We report the measurement of reaction cross sections (σ_{R}^{ex}) of ^{27,29}F with a carbon target at RIKEN. The unexpectedly large σ_{R}^{ex} and derived matter radius identify ^{29}F as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the 2p_{3/2} orbital, thereby vanishing the shell closure associated with the neutron number N=20. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of ^{27}F but are challenged for ^{29}F.
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Affiliation(s)
- S Bagchi
- Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany
- Justus-Liebig University, 35392 Giessen, Germany
| | - R Kanungo
- Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Y K Tanaka
- Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany
- Justus-Liebig University, 35392 Giessen, Germany
| | - H Geissel
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany
- Justus-Liebig University, 35392 Giessen, Germany
| | - P Doornenbal
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - W Horiuchi
- Department of Physics, Hokkaido University, Sapporo 060-0810, Japan
| | - G Hagen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - T Suzuki
- Department of Physics, Nihon University, Setagaya-ku, Tokyo 156-8550, Japan
| | - N Tsunoda
- Center for Nuclear Study, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - D S Ahn
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - H Baba
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - K Behr
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany
| | - F Browne
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - S Chen
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - M L Cortés
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - A Estradé
- Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - N Fukuda
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - M Holl
- Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - K Itahashi
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - N Iwasa
- Department of Physics, Tohoku University, Miyagi 980-8577, Japan
| | - G R Jansen
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- National Center for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - W G Jiang
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - S Kaur
- Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S Y Matsumoto
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
| | - S Momiyama
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - I Murray
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
- Institut de Physique Nucleaire, IN2P3, CNRS, Université Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
| | - T Nakamura
- Department of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo 152-8551, Japan
| | - S J Novario
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - H J Ong
- RCNP, Osaka University, Mihogaoka, Ibaraki, Osaka 567 0047, Japan
| | - T Otsuka
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - T Papenbrock
- Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - S Paschalis
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - A Prochazka
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany
| | - C Scheidenberger
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany
- Justus-Liebig University, 35392 Giessen, Germany
| | - P Schrock
- Center for Nuclear Study, University of Tokyo, RIKEN Campus, Wako, Saitama 351-0198, Japan
| | - Y Shimizu
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - D Steppenbeck
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
- Center for Nuclear Study, University of Tokyo, RIKEN Campus, Wako, Saitama 351-0198, Japan
| | - H Sakurai
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - D Suzuki
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - H Suzuki
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - M Takechi
- Graduate School of Science and Technology, Niigata University, Niigata 950-2102, Japan
| | - H Takeda
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - S Takeuchi
- Department of Physics, Tokyo Institute of Technology, 2-12-1 O-Okayama, Meguro, Tokyo 152-8551, Japan
| | - R Taniuchi
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Physics, University of York, Heslington, York YO10 5DD, United Kingdom
| | - K Wimmer
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - K Yoshida
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
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5
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Ayangeakaa AD, Janssens RVF, Zhu S, Little D, Henderson J, Wu CY, Hartley DJ, Albers M, Auranen K, Bucher B, Carpenter MP, Chowdhury P, Cline D, Crawford HL, Fallon P, Forney AM, Gade A, Hayes AB, Kondev FG, Lauritsen T, Li J, Macchiavelli AO, Rhodes D, Seweryniak D, Stolze SM, Walters WB, Wu J. Evidence for Rigid Triaxial Deformation in ^{76}Ge from a Model-Independent Analysis. Phys Rev Lett 2019; 123:102501. [PMID: 31573317 DOI: 10.1103/physrevlett.123.102501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Indexed: 06/10/2023]
Abstract
An extensive, model-independent analysis of the nature of triaxial deformation in ^{76}Ge, a candidate for neutrinoless double-beta (0νββ) decay, was carried out following multistep Coulomb excitation. Shape parameters deduced on the basis of a rotational-invariant sum-rule analysis provided considerable insight into the underlying collectivity of the ground-state and γ bands. Both sequences were determined to be characterized by the same β and γ deformation parameter values. In addition, compelling evidence for low-spin, rigid triaxial deformation in ^{76}Ge was obtained for the first time from the analysis of the statistical fluctuations of the quadrupole asymmetry deduced from the measured E2 matrix elements. These newly determined shape parameters are important input and constraints for calculations aimed at providing, with suitable accuracy, the nuclear matrix elements relevant to 0νββ.
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Affiliation(s)
- A D Ayangeakaa
- Department of Physics, United States Naval Academy, Annapolis, Maryland 21402, USA
| | - R V F Janssens
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Triangle Universities Nuclear Laboratory, Duke University, Durham, North Carolina 27708, USA
| | - S Zhu
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Little
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
- Triangle Universities Nuclear Laboratory, Duke University, Durham, North Carolina 27708, USA
| | - J Henderson
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C Y Wu
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D J Hartley
- Department of Physics, United States Naval Academy, Annapolis, Maryland 21402, USA
| | - M Albers
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - K Auranen
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B Bucher
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M P Carpenter
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Chowdhury
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, Massachusetts 01854, USA
| | - D Cline
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A M Forney
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - A Gade
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - A B Hayes
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
| | - F G Kondev
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - T Lauritsen
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Li
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - D Rhodes
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Seweryniak
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S M Stolze
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - W B Walters
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - J Wu
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
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6
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Crawford HL, Fallon P, Macchiavelli AO, Doornenbal P, Aoi N, Browne F, Campbell CM, Chen S, Clark RM, Cortés ML, Cromaz M, Ideguchi E, Jones MD, Kanungo R, MacCormick M, Momiyama S, Murray I, Niikura M, Paschalis S, Petri M, Sakurai H, Salathe M, Schrock P, Steppenbeck D, Takeuchi S, Tanaka YK, Taniuchi R, Wang H, Wimmer K. First Spectroscopy of the Near Drip-line Nucleus ^{40}Mg. Phys Rev Lett 2019; 122:052501. [PMID: 30822018 DOI: 10.1103/physrevlett.122.052501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Indexed: 06/09/2023]
Abstract
One of the most exotic light neutron-rich nuclei currently accessible for experimental study is ^{40}Mg, which lies at the intersection of the nucleon magic number N=28 and the neutron drip line. Low-lying excited states of ^{40}Mg have been studied for the first time following a one-proton removal reaction from ^{41}Al, performed at the Radioactive Isotope Beam Factory of RIKEN Nishina Center with the DALI2 γ-ray array and the ZeroDegree spectrometer. Two γ-ray transitions were observed, suggesting an excitation spectrum that shows unexpected properties as compared to both the systematics along the Z=12, N≥20 Mg isotopes and available state-of-the-art theoretical model predictions. A possible explanation for the observed structure involves weak-binding effects in the low-lying excitation spectrum.
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Affiliation(s)
- H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Doornenbal
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - N Aoi
- Research Center for Nuclear Physics (RCNP), Osaka University, Mihogakoa, Ibaraki, Osaka 567-0047, Japan
| | - F Browne
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S Chen
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - R M Clark
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M L Cortés
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - M Cromaz
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - E Ideguchi
- Research Center for Nuclear Physics (RCNP), Osaka University, Mihogakoa, Ibaraki, Osaka 567-0047, Japan
| | - M D Jones
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - R Kanungo
- Astronomy and Physics Department, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - M MacCormick
- Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay Cedex 91406, France
| | - S Momiyama
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - I Murray
- Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay Cedex 91406, France
| | - M Niikura
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - S Paschalis
- Department of Physics, University of York, Heslington, York, England YO10 5DD, United Kingdom
| | - M Petri
- Department of Physics, University of York, Heslington, York, England YO10 5DD, United Kingdom
| | - H Sakurai
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - M Salathe
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Schrock
- Center for Nuclear Study, University of Tokyo, RIKEN Campus, Wako, Saitama 351-0198, Japan
| | - D Steppenbeck
- Center for Nuclear Study, University of Tokyo, RIKEN Campus, Wako, Saitama 351-0198, Japan
| | - S Takeuchi
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
- Department of Physics, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
| | - Y K Tanaka
- GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstrasse 1, 64291 Darmstadt, Germany
| | - R Taniuchi
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - H Wang
- RIKEN Nishina Center, Wako, Saitama 351-0198, Japan
| | - K Wimmer
- Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
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7
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Gates JM, Pang GK, Pore JL, Gregorich KE, Kwarsick JT, Savard G, Esker NE, Kireeff Covo M, Mogannam MJ, Batchelder JC, Bleuel DL, Clark RM, Crawford HL, Fallon P, Hubbard KK, Hurst AM, Kolaja IT, Macchiavelli AO, Morse C, Orford R, Phair L, Stoyer MA. First Direct Measurements of Superheavy-Element Mass Numbers. Phys Rev Lett 2018; 121:222501. [PMID: 30547624 DOI: 10.1103/physrevlett.121.222501] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 09/07/2018] [Indexed: 06/09/2023]
Abstract
An experiment was performed at Lawrence Berkeley National Laboratory's 88-in. Cyclotron to determine the mass number of a superheavy element. The measurement resulted in the observation of two α-decay chains, produced via the ^{243}Am(^{48}Ca,xn)^{291-x}Mc reaction, that were separated by mass-to-charge ratio (A/q) and identified by the combined BGS+FIONA apparatus. One event occurred at A/q=284 and was assigned to ^{284}Nh (Z=113), the α-decay daughter of ^{288}Mc (Z=115), while the second occurred at A/q=288 and was assigned to ^{288}Mc. This experiment represents the first direct measurements of the mass numbers of superheavy elements, confirming previous (indirect) mass-number assignments.
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Affiliation(s)
- J M Gates
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - G K Pang
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J L Pore
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - K E Gregorich
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J T Kwarsick
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- University of California, Berkeley, California 94720, USA
| | - G Savard
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- University of Chicago, Chicago, Illinois 60637, USA
| | - N E Esker
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - M Kireeff Covo
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M J Mogannam
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J C Batchelder
- University of California, Berkeley, California 94720, USA
| | - D L Bleuel
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R M Clark
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - H L Crawford
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Fallon
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - K K Hubbard
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- University of California, Berkeley, California 94720, USA
| | - A M Hurst
- University of California, Berkeley, California 94720, USA
| | - I T Kolaja
- University of California, Berkeley, California 94720, USA
| | - A O Macchiavelli
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C Morse
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - R Orford
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- McGill University, Montreal, Québec H3A 0G4, Canada
| | - L Phair
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M A Stoyer
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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8
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Kay BP, Hoffman CR, Macchiavelli AO. Effect of Weak Binding on the Apparent Spin-Orbit Splitting in Nuclei. Phys Rev Lett 2017; 119:182502. [PMID: 29219588 DOI: 10.1103/physrevlett.119.182502] [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: 05/25/2017] [Indexed: 06/07/2023]
Abstract
The apparent splitting between orbitals that are spin-orbit partners can be substantially influenced by the effects of weak binding. In particular, such effects can account for the observed decrease in separation of the neutron 1p_{3/2} and 1p_{1/2} orbitals between the ^{41}Ca and ^{35}Si isotopes. This behavior has been the subject of recent experimental and theoretical works and cited as evidence for a proton "bubble" in ^{34}Si causing an explicit weakening of the spin-orbit interaction. The results reported here suggest that the change in the separation between the 1p_{3/2} and 1p_{1/2} partners occurs dominantly because of the behavior of the energies of these 1p neutron states near zero binding.
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Affiliation(s)
- B P Kay
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C R Hoffman
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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9
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Bucher B, Zhu S, Wu CY, Janssens RVF, Bernard RN, Robledo LM, Rodríguez TR, Cline D, Hayes AB, Ayangeakaa AD, Buckner MQ, Campbell CM, Carpenter MP, Clark JA, Crawford HL, David HM, Dickerson C, Harker J, Hoffman CR, Kay BP, Kondev FG, Lauritsen T, Macchiavelli AO, Pardo RC, Savard G, Seweryniak D, Vondrasek R. Direct Evidence for Octupole Deformation in ^{146}Ba and the Origin of Large E1 Moment Variations in Reflection-Asymmetric Nuclei. Phys Rev Lett 2017; 118:152504. [PMID: 28452498 DOI: 10.1103/physrevlett.118.152504] [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: 01/13/2017] [Indexed: 06/07/2023]
Abstract
Despite the more than 1 order of magnitude difference between the measured dipole moments in ^{144}Ba and ^{146}Ba, the octupole correlations in ^{146}Ba are found to be as strong as those in ^{144}Ba with a similarly large value of B(E3;3^{-}→0^{+}) determined as 48(+21-29) W.u. The new results not only establish unambiguously the presence of a region of octupole deformation centered on these neutron-rich Ba isotopes, but also manifest the dependence of the electric dipole moments on the occupancy of different neutron orbitals in nuclei with enhanced octupole strength, as revealed by fully microscopic calculations.
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Affiliation(s)
- B Bucher
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
- Idaho National Laboratory, Idaho Falls, Idaho 83415, USA
| | - S Zhu
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C Y Wu
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R V F Janssens
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - R N Bernard
- Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - L M Robledo
- Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - T R Rodríguez
- Departamento de Física Teórica, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - D Cline
- University of Rochester, Rochester, New York 14627, USA
| | - A B Hayes
- University of Rochester, Rochester, New York 14627, USA
| | - A D Ayangeakaa
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Q Buckner
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C M Campbell
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J A Clark
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - H L Crawford
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - H M David
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C Dickerson
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Harker
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- University of Maryland, College Park, Maryland 20742, USA
| | - C R Hoffman
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B P Kay
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A O Macchiavelli
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - R C Pardo
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - G Savard
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - R Vondrasek
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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10
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Parker JJ, Wiedenhöver I, Cottle PD, Baker J, McPherson D, Riley MA, Santiago-Gonzalez D, Volya A, Bader VM, Baugher T, Bazin D, Gade A, Ginter T, Iwasaki H, Loelius C, Morse C, Recchia F, Smalley D, Stroberg SR, Whitmore K, Weisshaar D, Lemasson A, Crawford HL, Macchiavelli AO, Wimmer K. Isomeric Character of the Lowest Observed 4^{+} State in ^{44}S. Phys Rev Lett 2017; 118:052501. [PMID: 28211717 DOI: 10.1103/physrevlett.118.052501] [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: 04/03/2016] [Indexed: 06/06/2023]
Abstract
Previous experiments observed a 4^{+} state in the N=28 nucleus ^{44}S and suggested that this state may exhibit a hindered E2-decay rate, inconsistent with being a member of the collective ground state band. We populate this state via two-proton knockout from a beam of exotic ^{46}Ar projectiles and measure its lifetime using the recoil distance method with the GRETINA γ-ray spectrometer. The result, 76(14)_{stat}(20)_{syst} ps, implies a hindered transition of B(E2;4^{+}→2_{1}^{+})=0.61(19) single-particle or Weisskopf units strength and supports the interpretation of the 4^{+} state as a K=4 isomer, the first example of a high-K isomer in a nucleus of such low mass.
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Affiliation(s)
- J J Parker
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - I Wiedenhöver
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - P D Cottle
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - J Baker
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - D McPherson
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - M A Riley
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - D Santiago-Gonzalez
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - A Volya
- Department of Physics, Florida State University, Tallahassee, Florida, 32306, USA
| | - V M Bader
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - T Baugher
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - D Bazin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Gade
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - T Ginter
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - H Iwasaki
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - C Loelius
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - C Morse
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - F Recchia
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Smalley
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - S R Stroberg
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - K Whitmore
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan, 48824, USA
| | - D Weisshaar
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - A Lemasson
- Grand Accélérateur National dIons Lourds (GANIL), CEA/DSM-CNRS/IN2P3 Caen, France
| | - H L Crawford
- Lawrence Berkeley National Laboratory, Nuclear Science Division, 1 Cyclotron Road, Berkeley, California 94720-8153, USA
| | - A O Macchiavelli
- Lawrence Berkeley National Laboratory, Nuclear Science Division, 1 Cyclotron Road, Berkeley, California 94720-8153, USA
| | - K Wimmer
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
- Department of Physics, Central Michigan University, Mt. Pleasant, Michigan 48859, USA
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11
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Bucher B, Zhu S, Wu CY, Janssens RVF, Cline D, Hayes AB, Albers M, Ayangeakaa AD, Butler PA, Campbell CM, Carpenter MP, Chiara CJ, Clark JA, Crawford HL, Cromaz M, David HM, Dickerson C, Gregor ET, Harker J, Hoffman CR, Kay BP, Kondev FG, Korichi A, Lauritsen T, Macchiavelli AO, Pardo RC, Richard A, Riley MA, Savard G, Scheck M, Seweryniak D, Smith MK, Vondrasek R, Wiens A. Direct Evidence of Octupole Deformation in Neutron-Rich ^{144}Ba. Phys Rev Lett 2016; 116:112503. [PMID: 27035298 DOI: 10.1103/physrevlett.116.112503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Indexed: 06/05/2023]
Abstract
The neutron-rich nucleus ^{144}Ba (t_{1/2}=11.5 s) is expected to exhibit some of the strongest octupole correlations among nuclei with mass numbers A less than 200. Until now, indirect evidence for such strong correlations has been inferred from observations such as enhanced E1 transitions and interleaving positive- and negative-parity levels in the ground-state band. In this experiment, the octupole strength was measured directly by sub-barrier, multistep Coulomb excitation of a post-accelerated 650-MeV ^{144}Ba beam on a 1.0-mg/cm^{2} ^{208}Pb target. The measured value of the matrix element, ⟨3_{1}^{-}∥M(E3)∥0_{1}^{+}⟩=0.65(+17/-23) eb^{3/2}, corresponds to a reduced B(E3) transition probability of 48(+25/-34) W.u. This result represents an unambiguous determination of the octupole collectivity, is larger than any available theoretical prediction, and is consistent with octupole deformation.
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Affiliation(s)
- B Bucher
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - S Zhu
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C Y Wu
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R V F Janssens
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Cline
- University of Rochester, Rochester, New York 14627, USA
| | - A B Hayes
- University of Rochester, Rochester, New York 14627, USA
| | - M Albers
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A D Ayangeakaa
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P A Butler
- University of Liverpool, Liverpool L69 7ZE, United Kingdom
| | - C M Campbell
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C J Chiara
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- University of Maryland, College Park, Maryland 20742, USA
| | - J A Clark
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | | | - M Cromaz
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - H M David
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C Dickerson
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - E T Gregor
- University of the West of Scotland, Paisley PA1 2BE, United Kingdom
- SUPA, Scottish Universities Physics Alliance, Glasgow G12 8QQ, United Kingdom
| | - J Harker
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- University of Maryland, College Park, Maryland 20742, USA
| | - C R Hoffman
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B P Kay
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Korichi
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- CSNSM, IN2P3-CNRS, bâtiment 104-108, F-91405 Orsay Campus, France
| | - T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A O Macchiavelli
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - R C Pardo
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Richard
- Ohio University, Athens, Ohio 45701, USA
| | - M A Riley
- Florida State University, Tallahassee, Florida 32306, USA
| | - G Savard
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Scheck
- University of the West of Scotland, Paisley PA1 2BE, United Kingdom
- SUPA, Scottish Universities Physics Alliance, Glasgow G12 8QQ, United Kingdom
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M K Smith
- University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - R Vondrasek
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A Wiens
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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12
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David HM, Chen J, Seweryniak D, Kondev FG, Gates JM, Gregorich KE, Ahmad I, Albers M, Alcorta M, Back BB, Baartman B, Bertone PF, Bernstein LA, Campbell CM, Carpenter MP, Chiara CJ, Clark RM, Cromaz M, Doherty DT, Dracoulis GD, Esker NE, Fallon P, Gothe OR, Greene JP, Greenlees PT, Hartley DJ, Hauschild K, Hoffman CR, Hota SS, Janssens RVF, Khoo TL, Konki J, Kwarsick JT, Lauritsen T, Macchiavelli AO, Mudder PR, Nair C, Qiu Y, Rissanen J, Rogers AM, Ruotsalainen P, Savard G, Stolze S, Wiens A, Zhu S. Publisher's Note: Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in (254)Rf [Phys. Rev. Lett. 115, 132502 (2015)]. Phys Rev Lett 2015; 115:169902. [PMID: 26550909 DOI: 10.1103/physrevlett.115.169902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Indexed: 06/05/2023]
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13
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David HM, Chen J, Seweryniak D, Kondev FG, Gates JM, Gregorich KE, Ahmad I, Albers M, Alcorta M, Back BB, Baartman B, Bertone PF, Bernstein LA, Campbell CM, Carpenter MP, Chiara CJ, Clark RM, Cromaz M, Doherty DT, Dracoulis GD, Esker NE, Fallon P, Gothe OR, Greene JP, Greenlees PT, Hartley DJ, Hauschild K, Hoffman CR, Hota SS, Janssens RVF, Khoo TL, Konki J, Kwarsick JT, Lauritsen T, Macchiavelli AO, Mudder PR, Nair C, Qiu Y, Rissanen J, Rogers AM, Ruotsalainen P, Savard G, Stolze S, Wiens A, Zhu S. Decay and Fission Hindrance of Two- and Four-Quasiparticle K Isomers in ^{254}Rf. Phys Rev Lett 2015; 115:132502. [PMID: 26451549 DOI: 10.1103/physrevlett.115.132502] [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: 06/24/2015] [Indexed: 06/05/2023]
Abstract
Two isomers decaying by electromagnetic transitions with half-lives of 4.7(1.1) and 247(73) μs have been discovered in the heavy ^{254}Rf nucleus. The observation of the shorter-lived isomer was made possible by a novel application of a digital data acquisition system. The isomers were interpreted as the K^{π}=8^{-}, ν^{2}(7/2^{+}[624],9/2^{-}[734]) two-quasineutron and the K^{π}=16^{+}, 8^{-}ν^{2}(7/2^{+}[624],9/2^{-}[734])⊗8^{-}π^{2}(7/2^{-}[514],9/2^{+}[624]) four-quasiparticle configurations, respectively. Surprisingly, the lifetime of the two-quasiparticle isomer is more than 4 orders of magnitude shorter than what has been observed for analogous isomers in the lighter N=150 isotones. The four-quasiparticle isomer is longer lived than the ^{254}Rf ground state that decays exclusively by spontaneous fission with a half-life of 23.2(1.1) μs. The absence of sizable fission branches from either of the isomers implies unprecedented fission hindrance relative to the ground state.
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Affiliation(s)
- H M David
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Chen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - D Seweryniak
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - F G Kondev
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J M Gates
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - K E Gregorich
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - I Ahmad
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Albers
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - M Alcorta
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B B Back
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - B Baartman
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P F Bertone
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - L A Bernstein
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - C M Campbell
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M P Carpenter
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - C J Chiara
- Argonne National Laboratory, Argonne, Illinois 60439, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
| | - R M Clark
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Cromaz
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - D T Doherty
- School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
| | - G D Dracoulis
- Department of Nuclear Physics, R.S.P.E., Australian National University, Canberra A.C.T. 2601, Australia
| | - N E Esker
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Fallon
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - O R Gothe
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - J P Greene
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P T Greenlees
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - D J Hartley
- United States Naval Academy, Annapolis, Maryland 21402, USA
| | - K Hauschild
- CSNSM, IN2P3-CNRS, F-91405 Orsay Campus, France
| | - C R Hoffman
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S S Hota
- Department of Physics, University of Massachusetts, Lowell, Massachusetts 01854, USA
| | - R V F Janssens
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - T L Khoo
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - J Konki
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - J T Kwarsick
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - A O Macchiavelli
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P R Mudder
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - C Nair
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Y Qiu
- Department of Physics, University of Massachusetts, Lowell, Massachusetts 01854, USA
| | - J Rissanen
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A M Rogers
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - P Ruotsalainen
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - G Savard
- Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - S Stolze
- Department of Physics, University of Jyväskylä, FIN-40014 Jyväskylä, Finland
| | - A Wiens
- Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S Zhu
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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14
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Crawford HL, Clark RM, Fallon P, Macchiavelli AO, Baugher T, Bazin D, Beausang CW, Berryman JS, Bleuel DL, Campbell CM, Cromaz M, de Angelis G, Gade A, Hughes RO, Lee IY, Lenzi SM, Nowacki F, Paschalis S, Petri M, Poves A, Ratkiewicz A, Ross TJ, Sahin E, Weisshaar D, Wimmer K, Winkler R. Quadrupole collectivity in neutron-rich Fe and Cr isotopes. Phys Rev Lett 2013; 110:242701. [PMID: 25165918 DOI: 10.1103/physrevlett.110.242701] [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: 04/11/2013] [Indexed: 06/03/2023]
Abstract
Intermediate-energy Coulomb excitation measurements are performed on the N ≥ 40 neutron-rich nuclei (66,68)Fe and (64)Cr. The reduced transition matrix elements providing a direct measure of the quadrupole collectivity B(E2;2(1)(+) → 0(1)(+)) are determined for the first time in (68)Fe(42) and (64)Cr(40) and confirm a previous recoil distance method lifetime measurement in (66)Fe(40). The results are compared to state-of-the-art large-scale shell-model calculations within the full fpgd neutron orbital model space using the Lenzi-Nowacki-Poves-Sieja effective interaction and confirm the results of the calculations that show these nuclei are well deformed.
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Affiliation(s)
- H L Crawford
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - R M Clark
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - P Fallon
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A O Macchiavelli
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - T Baugher
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - D Bazin
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - C W Beausang
- University of Richmond, Richmond, Virginia 23173, USA
| | - J S Berryman
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - D L Bleuel
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
| | - C M Campbell
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Cromaz
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - G de Angelis
- Laboratori Nazionali di Legnaro, INFN, I-35020 Legnaro, Padova, Italy
| | - A Gade
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - R O Hughes
- University of Richmond, Richmond, Virginia 23173, USA
| | - I Y Lee
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - S M Lenzi
- Dipartimento di Fisica dell'Università and INFN, Sezione di Padova, I-35131 Padova, Italy
| | - F Nowacki
- IPHC, IN2P3-CNRS et Université de Strasbourg, F-67037 Strasbourg, France
| | - S Paschalis
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - M Petri
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - A Poves
- Departamento de Física Teórica e IFT-UAM/CSIC, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - A Ratkiewicz
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - T J Ross
- University of Richmond, Richmond, Virginia 23173, USA
| | - E Sahin
- Laboratori Nazionali di Legnaro, INFN, I-35020 Legnaro, Padova, Italy
| | - D Weisshaar
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
| | - K Wimmer
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA and Department of Physics, Central Michigan University, Mount Pleasant, Michigan 48859, USA
| | - R Winkler
- National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
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15
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Lee ABF, Lane GJ, Dracoulis GD, Macchiavelli AO, Fallon P, Clark RM, Xu FR, Dong DX. Observation of new h9/2and h11/2bands in 187T1. EPJ Web of Conferences 2012. [DOI: 10.1051/epjconf/20123506002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Petri M, Fallon P, Macchiavelli AO, Paschalis S, Starosta K, Baugher T, Bazin D, Cartegni L, Clark RM, Crawford HL, Cromaz M, Dewald A, Gade A, Grinyer GF, Gros S, Hackstein M, Jeppesen HB, Lee IY, McDaniel S, Miller D, Rajabali MM, Ratkiewicz A, Rother W, Voss P, Walsh KA, Weisshaar D, Wiedeking M, Brown BA. Lifetime measurement of the 2(1)+ state in 20C. Phys Rev Lett 2011; 107:102501. [PMID: 21981497 DOI: 10.1103/physrevlett.107.102501] [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: 01/21/2011] [Indexed: 05/31/2023]
Abstract
Establishing how and when large N/Z values require modified or new theoretical tools is a major quest in nuclear physics. Here we report the first measurement of the lifetime of the 2(1)+ state in the near-dripline nucleus 20C. The deduced value of τ(2(1)+)=9.8±2.8(stat)(-1.1)(+0.5)(syst) ps gives a reduced transition probability of B(E2; 2(1)+→0(g.s.)+)=7.5(-1.7)(+3.0)(stat)(-0.4)(+1.0)(syst) e2 fm4 in good agreement with a shell model calculation using isospin-dependent effective charges.
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Affiliation(s)
- M Petri
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
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17
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Wimmer K, Kröll T, Krücken R, Bildstein V, Gernhäuser R, Bastin B, Bree N, Diriken J, Van Duppen P, Huyse M, Patronis N, Vermaelen P, Voulot D, Van de Walle J, Wenander F, Fraile LM, Chapman R, Hadinia B, Orlandi R, Smith JF, Lutter R, Thirolf PG, Labiche M, Blazhev A, Kalkühler M, Reiter P, Seidlitz M, Warr N, Macchiavelli AO, Jeppesen HB, Fiori E, Georgiev G, Schrieder G, Das Gupta S, Lo Bianco G, Nardelli S, Butterworth J, Johansen J, Riisager K. Discovery of the shape coexisting 0+ state in 32 Mg by a two neutron transfer reaction. Phys Rev Lett 2010; 105:252501. [PMID: 21231582 DOI: 10.1103/physrevlett.105.252501] [Citation(s) in RCA: 6] [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: 08/05/2010] [Indexed: 05/30/2023]
Abstract
The "island of inversion" nucleus 32 Mg has been studied by a (t, p) two neutron transfer reaction in inverse kinematics at REX-ISOLDE. The shape coexistent excited 0+ state in 32 Mg has been identified by the characteristic angular distribution of the protons of the Δ L=0 transfer. The excitation energy of 1058 keV is much lower than predicted by any theoretical model. The low γ-ray intensity observed for the decay of this 0+ state indicates a lifetime of more than 10 ns. Deduced spectroscopic amplitudes are compared with occupation numbers from shell-model calculations.
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Affiliation(s)
- K Wimmer
- Physik Department E12, Technische Universität München, 85748 Garching, Germany
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18
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Wuosmaa AH, Back BB, Baker S, Brown BA, Deibel CM, Fallon P, Hoffman CR, Kay BP, Lee HY, Lighthall JC, Macchiavelli AO, Marley ST, Pardo RC, Rehm KE, Schiffer JP, Shetty DV, Wiedeking M. ¹⁵C(d,p)¹⁶C reaction and exotic behavior in ¹⁶C. Phys Rev Lett 2010; 105:132501. [PMID: 21230766 DOI: 10.1103/physrevlett.105.132501] [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: 06/16/2010] [Indexed: 05/30/2023]
Abstract
We have studied the ¹⁵C(d,p)¹⁶C reaction in inverse kinematics using the Helical Orbit Spectrometer at Argonne National Laboratory. Prior studies of electromagnetic-transition rates in ¹⁶C suggested an exotic decoupling of the valence neutrons from the core in that nucleus. Neutron-adding spectroscopic factors give a different probe of the wave functions of the relevant states in ¹⁶C. Shell-model calculations reproduce both the present transfer data and the previously measured transition rates, suggesting that ¹⁶C may be described without invoking very exotic phenomena.
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Affiliation(s)
- A H Wuosmaa
- Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252, USA
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19
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Wiedeking M, Fallon P, Macchiavelli AO, Gibelin J, Basunia MS, Clark RM, Cromaz M, Deleplanque MA, Gros S, Jeppesen HB, Lake PT, Lee IY, Moretto LG, Pavan J, Phair L, Rodriguez-Vietiez E, Bernstein LA, Bleuel DL, Burke JT, Lesher SR, Lyles BF, Scielzo ND. Lifetime measurement of the first excited 2+ state in 16C. Phys Rev Lett 2008; 100:152501. [PMID: 18518099 DOI: 10.1103/physrevlett.100.152501] [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: 11/20/2007] [Indexed: 05/26/2023]
Abstract
The lifetime of the 2_+(1) state in 16C has been measured with the recoil distance method using the 9Be(9Be,2p) fusion-evaporation reaction at a beam energy of 40 MeV. The mean lifetime was measured to be 11.7(20) ps corresponding to a B(E2;2_+(1)-->0+) value of 4.15(73)e_2 fm_4 [1.73(30) W.u.], consistent with other even-even closed shell nuclei. Our result does not support an interpretation for "decoupled" valence neutrons.
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Affiliation(s)
- M Wiedeking
- Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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20
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Lopez-Martens A, Døssing T, Khoo TL, Matsuo M, Herskind B, Lauritsen T, Carpenter MP, Janssens RVF, Hackman G, Lee IY, Macchiavelli AO, Vigezzi E, Yoshida K. Motional narrowing and ergodic bands in excited superdeformed states of 194Hg. Phys Rev Lett 2008; 100:102501. [PMID: 18352178 DOI: 10.1103/physrevlett.100.102501] [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: 10/31/2007] [Indexed: 05/26/2023]
Abstract
The E(gamma) - E(gamma) coincidence spectra from the electromagnetic decay of excited superdeformed states in (194)Hg reveal surprisingly narrow ridges, parallel to the diagonal. A total of 100-150 excited bands are found to contribute to these ridges, which account for nearly all the unresolved E2 decay strength. Comparison with theory suggests that these excited bands have many components in their wave functions, yet they display remarkable rotational coherence. This phenomenon can be explained in terms of the combination of shell effects and motional narrowing.
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Affiliation(s)
- A Lopez-Martens
- C.S.N.S.M, IN2P3-CNRS, Batiment 104-108, 91405 Orsay, France
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21
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Paul ES, Twin PJ, Evans AO, Pipidis A, Riley MA, Simpson J, Appelbe DE, Campbell DB, Choy PTW, Clark RM, Cromaz M, Fallon P, Görgen A, Joss DT, Lee IY, Macchiavelli AO, Nolan PJ, Ward D, Ragnarsson I. Return of collective rotation in 157Er and 158Er at ultrahigh spin. Phys Rev Lett 2007; 98:012501. [PMID: 17358470 DOI: 10.1103/physrevlett.98.012501] [Citation(s) in RCA: 2] [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: 09/05/2006] [Indexed: 05/14/2023]
Abstract
A new frontier of discrete-line gamma-ray spectroscopy at ultrahigh spin has been opened in the rare-earth nuclei (157,158) Er. Four rotational structures, displaying high moments of inertia, have been identified, which extend up to spin approximately 65 variant Planck's over 2pi and bypass the band-terminating states in these nuclei which occur at approximately 45 variant Planck's over 2pi. Cranked Nilsson-Strutinsky calculations suggest that these structures arise from well-deformed triaxial configurations that lie in a valley of favored shell energy which also includes the triaxial strongly deformed bands in (161-167) Lu.
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Affiliation(s)
- E S Paul
- Oliver Lodge Laboratory, University of Liverpool, Liverpool, UK
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22
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Rudolph D, Carlsson BG, Ragnarsson I, Aberg S, Andreoiu C, Bentley MA, Carpenter MP, Charity RJ, Clark RM, Cromaz M, Ekman J, Fahlander C, Fallon P, Ideguchi E, Macchiavelli AO, Mineva MN, Reviol W, Sarantites DG, Seweryniak D, Williams SJ. 58Ni: an unpaired band crossing at new heights of angular momentum for rotating nuclei. Phys Rev Lett 2006; 96:092501. [PMID: 16606258 DOI: 10.1103/physrevlett.96.092501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Indexed: 05/08/2023]
Abstract
High-spin states in 58Ni have been investigated by means of the fusion-evaporation reaction 28Si(32S, 2p)58Ni at 130 MeV beam energy. Discrete-energy levels are observed in 58Ni at record-breaking 42 MeV excitation energy and angular momenta in excess of 30h. The states form regular rotational bands with unprecedented high rotational frequencies. A comparison with configuration dependent cranked Nilsson-Strutinsky calculations reveals an exceptional two-band crossing scenario, the interaction strength of which is strongly shape dependent.
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Affiliation(s)
- D Rudolph
- Department of Physics, Lund University, S-22100 Lund, Sweden
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23
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Hayes AB, Cline D, Wu CY, Ai J, Amro H, Beausang C, Casten RF, Gerl J, Hecht AA, Heinz A, Hughes R, Janssens RVF, Lister CJ, Macchiavelli AO, Meyer DA, Moore EF, Napiorkowski P, Pardo RC, Schlegel C, Seweryniak D, Simon MW, Srebrny J, Teng R, Vetter K, Wollersheim HJ. Breakdown of K selection in 178Hf. Phys Rev Lett 2006; 96:042505. [PMID: 16486815 DOI: 10.1103/physrevlett.96.042505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Indexed: 05/06/2023]
Abstract
Coulomb activation of the four quasiparticle Kpi=16+ 178Hf isomer (t1/2=31 y) has led to the measurement of a set of Elamda matrix elements coupling the isomer band to the ground band. The present data combined with earlier 178 Hf Coulomb excitation data have probed the components in the wave functions and revealed the onset and saturation of K mixing in low-K bands, whereas the mixing is negligible in the high-K bands. The implications can be applied to other quadrupole-deformed nuclei.
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Affiliation(s)
- A B Hayes
- Nuclear Structure Research Laboratory, Department of Physics, University of Rochester, Rochester, New York 14627, USA
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24
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Clark RM, Macchiavelli AO, Fortunato L, Krücken R. Critical-point description of the transition from vibrational to rotational regimes in the pairing phase. Phys Rev Lett 2006; 96:032501. [PMID: 16486691 DOI: 10.1103/physrevlett.96.032501] [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: 09/14/2005] [Indexed: 05/06/2023]
Abstract
An approximate solution at the critical point of the pairing transition from harmonic vibration to deformed rotation in gauge space is found by analytic solution of the collective pairing Hamiltonian. The eigenvalues are expressed in terms of the zeros of Bessel functions of integer order. The results are compared to the pairing bands based on the Pb isotopes.
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Affiliation(s)
- R M Clark
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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25
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Valiente-Dobón JJ, Steinhardt T, Svensson CE, Afanasjev AV, Ragnarsson I, Andreoiu C, Austin RAE, Carpenter MP, Dashdorj D, de Angelis G, Dönau F, Eberth J, Farnea E, Freeman SJ, Gadea A, Garrett PE, Görgen A, Grinyer GF, Hyland B, Jenkins D, Johnston-Theasby F, Joshi P, Jungclaus A, Lieb KP, Macchiavelli AO, Moore EF, Mukherjee G, Napoli DR, Phillips AA, Plettner C, Reviol W, Sarantites D, Schnare H, Schumaker MA, Schwengner R, Seweryniak D, Smith MB, Stefanescu I, Thelen O, Wadsworth R. Evidence for nontermination of rotational bands in 74Kr. Phys Rev Lett 2005; 95:232501. [PMID: 16384300 DOI: 10.1103/physrevlett.95.232501] [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: 07/18/2005] [Indexed: 05/05/2023]
Abstract
Three rotational bands in 74Kr were studied up to (in one case one transition short of) the maximum spin I(max) of their respective single-particle configurations. Their lifetimes have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments reveal a modest decrease, but far from a complete loss of collectivity at the maximum spin I(max). This feature, together with the results of mean field calculations, indicates that the observed bands do not terminate at I = I(max).
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Affiliation(s)
- J J Valiente-Dobón
- Department of Physics, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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26
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Stephens FS, Deleplanque MA, Lee IY, Macchiavelli AO, Ward D, Fallon P, Cromaz M, Clark RM, Descovich M, Diamond RM, Rodriguez-Vieitez E. Order-to-chaos transition in rotational nuclei. Phys Rev Lett 2005; 94:042501. [PMID: 15783551 DOI: 10.1103/physrevlett.94.042501] [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: 05/03/2004] [Indexed: 05/24/2023]
Abstract
We have developed a new method to study the order-to-chaos transition in rotational nuclei. Correlations between successive gamma rays are used to determine the average complexity of the intermediate levels and thereby the ratio of the interaction potential between levels to the level spacing. The measured ratios, 0.15 to 1.5, span the range from nearly fully ordered to nearly fully chaotic.
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Affiliation(s)
- F S Stephens
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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27
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Evans AO, Paul ES, Simpson J, Riley MA, Appelbe DE, Campbell DB, Choy PTW, Clark RM, Cromaz M, Fallon P, Görgen A, Joss DT, Lee IY, Macchiavelli AO, Nolan PJ, Pipidis A, Ward D, Ragnarsson I, Sarić F. High-spin structure beyond band termination in 157Er. Phys Rev Lett 2004; 92:252502. [PMID: 15245000 DOI: 10.1103/physrevlett.92.252502] [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: 10/24/2003] [Indexed: 05/24/2023]
Abstract
The angular-momentum induced transition from a deformed state of collective rotation to a noncollective configuration has been studied. In 157Er this transition manifests itself as favored band termination near I=45 Planck's. The feeding of these band terminating states has been investigated for the first time using the Gammasphere spectrometer. Many weakly populated states lying at high excitation energy that decay into these special states have been discovered. Cranked Nilsson-Strutinsky calculations suggest that these states arise from weakly collective "core-breaking" configurations.
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Affiliation(s)
- A O Evans
- Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 7ZE, United Kingdom
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28
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Vaman C, Fossan DB, Koike T, Starosta K, Lee IY, Macchiavelli AO. Chiral degeneracy in triaxial 104Rh. Phys Rev Lett 2004; 92:032501. [PMID: 14753867 DOI: 10.1103/physrevlett.92.032501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Indexed: 05/24/2023]
Abstract
Chiral doublet bands based on the pi g(9/2) multiply sign in circle nu h(11/2) configuration that achieve degeneracy at spin I=17 in the odd-odd triaxial 104Rh nucleus have been observed. Experimental verification of the interpretation has been tested against specific fingerprints of chirality in the intrinsic system.
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Affiliation(s)
- C Vaman
- Department of Physics and Astronomy, SUNY at Stony Brook, Stony Brook, New York 11794-3800, USA
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29
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Pattison LK, Cullen DM, Smith JF, Fletcher AM, Walker PM, El-Masri HM, Podolyák Z, Wood RJ, Scholey C, Wheldon C, Mukherjee G, Balabanski D, Djongolov M, Dalsgaard T, Thisgaard H, Sletten G, Kondev F, Jenkins D, Lane GJ, Lee IY, Macchiavelli AO, Frauendorf S, Almehed D. Multiphonon vibrations at high angular momentum in 182 Os. Phys Rev Lett 2003; 91:182501. [PMID: 14611278 DOI: 10.1103/physrevlett.91.182501] [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: 07/25/2002] [Indexed: 05/24/2023]
Abstract
Evidence is presented for multiphonon excitations based on a high-spin (25 Planck) intrinsic state in the deformed nucleus 182 Os. Angular momentum generation by this mode competes with collective rotation. The experimental data are compared with tilted-axis cranking calculations, supporting the vibrational interpretation. However, the lower experimental energies provide evidence that more complex interactions of states are playing a role.
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Affiliation(s)
- L K Pattison
- Schuster Laboratory, University of Manchester, Manchester M13 9PL, United Kingdom
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30
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Simons AJ, Wadsworth R, Jenkins DG, Clark RM, Cromaz M, Deleplanque MA, Diamond RM, Fallon P, Lane GJ, Lee IY, Macchiavelli AO, Stephens FS, Svensson CE, Vetter K, Ward D, Frauendorf S. Evidence for a new type of shears mechanism in 106Cd. Phys Rev Lett 2003; 91:162501. [PMID: 14611395 DOI: 10.1103/physrevlett.91.162501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2003] [Indexed: 05/24/2023]
Abstract
Lifetimes of states in the lowest lying positive parity band in 106Cd have been measured using the Doppler shift attenuation method. The deduced B(E2) transition rates show a marked decrease with increasing spin. Cranking and semiclassical model calculations suggest that the structure has the character of a shears-type band resulting from the coupling of g(9/2) proton holes to aligned pairs of h(11/2) and g(7/2) neutron particles. This is the first clear evidence for the phenomenon of "antimagnetic" rotation in nuclei.
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Affiliation(s)
- A J Simons
- Department of Physics, University of York, Heslington, York Y010 5DD, United Kingdom
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31
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Zhu S, Garg U, Nayak BK, Ghugre SS, Pattabiraman NS, Fossan DB, Koike T, Starosta K, Vaman C, Janssens RVF, Chakrawarthy RS, Whitehead M, Macchiavelli AO, Frauendorf S. A composite chiral pair of rotational bands in the odd-A nucleus 135Nd. Phys Rev Lett 2003; 91:132501. [PMID: 14525299 DOI: 10.1103/physrevlett.91.132501] [Citation(s) in RCA: 3] [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: 02/20/2003] [Revised: 05/14/2003] [Indexed: 05/24/2023]
Abstract
High-spin states in 135Nd were populated with the 110Pd(30Si,5n)135Nd reaction at a 30Si bombarding energy of 133 MeV. Two DeltaI=1 bands with close excitation energies and the same parity were observed. These bands are directly linked by DeltaI=1 and DeltaI=2 transitions. The chiral nature of these two bands is confirmed by comparison with three-dimensional tilted axis cranking calculations. This is the first observation of a three-quasiparticle chiral structure and establishes the primarily geometric nature of this phenomenon.
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Affiliation(s)
- S Zhu
- Physics Department, University of Notre Dame, Notre Dame, Indiana 46556, USA
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32
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Wilson AN, Dracoulis GD, Byrne AP, Davidson PM, Lane GJ, Clark RM, Fallon P, Görgen A, Macchiavelli AO, Ward D. Direct decays from superdeformed states in 192Pb observed using time-correlated gamma-ray spectroscopy. Phys Rev Lett 2003; 90:142501. [PMID: 12731911 DOI: 10.1103/physrevlett.90.142501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2002] [Indexed: 05/24/2023]
Abstract
Correlations of decays above and below isomeric states in the normally deformed minimum of 192Pb have been used to identify discrete transitions in the decay of the superdeformed (SD) band. The data establish the absolute excitation energy of the lowest observed SD level as 4.425 MeV. Extrapolation to the bandhead indicates that the excitation energy of the superdeformed well in 192Pb is 0.5 MeV lower than in the heavier isotope 194Pb. The results confirm the trend to decreasing excitation energy with decreasing neutron number predicted by both a macroscopic Strutinsky method approach and microscopic mean field calculations.
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Affiliation(s)
- A N Wilson
- Department of Nuclear Physics, Research School of Physical Sciences and Engineering, Australian National University, Canberra, ACT 0200 Australia.
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33
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Lauritsen T, Janssens RVF, Carpenter MP, Fallon P, Herskind B, Jenkins DG, Khoo TL, Kondev FG, Lopez-Martens A, Macchiavelli AO, Ward D, Saleem KA, Ahmad I, Clark RM, Cromaz M, Døssing T, Heinz AM, Korichi A, Lane G, Lister CJ, Seweryniak D. Octupole vibration in superdeformed 152(66)Dy86. Phys Rev Lett 2002; 89:282501. [PMID: 12513136 DOI: 10.1103/physrevlett.89.282501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2002] [Indexed: 05/24/2023]
Abstract
Nine transitions of dipole character have been identified linking an excited superdeformed (SD) band in 152Dy to the yrast SD band. As a result, the excitation energy of the lowest level in the excited SD band has been measured to be 14 238 keV. This corresponds to a 1.3 MeV excitation above the SD ground state. The levels in this band have tentatively been determined to be of negative parity and odd spin. The measured properties are consistent with an interpretation in terms of a rotational band built on a collective octupole vibration.
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Affiliation(s)
- T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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34
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Hayes AB, Cline D, Wu CY, Simon MW, Teng R, Gerl J, Schlegel C, Wollersheim HJ, Macchiavelli AO, Vetter K, Napiorkowski P, Srebrny J. Coulomb excitation paths of high-K isomer bands in 178Hf. Phys Rev Lett 2002; 89:242501. [PMID: 12484939 DOI: 10.1103/physrevlett.89.242501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2002] [Indexed: 05/24/2023]
Abstract
Three distinctly different mechanisms are shown to populate the K(pi)=6(+) (t(1/2)=77 ns), 16(+) (31 yr), and 8(-) (4 s) isomer bands of 178Hf by Coulomb excitation. High spin states of the three isomer bands were populated by Coulomb excitation of a hafnium target with a 650 MeV 136Xe beam. Although direct population of high-K bands is highly K-forbidden, isomer bands in 178Hf were populated up to spins 13(+)(K=6), 20(+)(K=16), and 14(-)(K=8) with in-band gamma yields of approximately 10(-4) of the ground state band. The data are consistent with a rapid increase in K mixing with increasing spin in the isomer bands.
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Affiliation(s)
- A B Hayes
- Nuclear Structure Research Laboratory, Department of Physics, University of Rochester, New York 14627, USA
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35
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Stephens FS, Deleplanque MA, Lee IY, Ward D, Fallon P, Cromaz M, Clark RM, Diamond RM, Macchiavelli AO, Vetter K. Rotational damping in ytterbium nuclei. Phys Rev Lett 2002; 88:142501. [PMID: 11955141 DOI: 10.1103/physrevlett.88.142501] [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: 10/19/2001] [Indexed: 05/23/2023]
Abstract
We have made the first clear measurements of rotational damping widths in nuclei. In a mixture of three Yb nuclei, these widths are 300 +/- 60 keV between 1.2 and 1.5 MeV gamma-ray energy [approximately (37-57)Planck's constant]. Compound damping and motional narrowing are discussed in connection with these results.
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Affiliation(s)
- F S Stephens
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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36
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Lauritsen T, Carpenter MP, Døssing T, Fallon P, Herskind B, Janssens RVF, Jenkins DG, Khoo TL, Kondev FG, Lopez-Martens A, Macchiavelli AO, Ward D, Abu Saleem KS, Ahmad I, Clark R, Cromaz M, Greene JP, Hannachi F, Heinz AM, Korichi A, Lane G, Lister CJ, Reiter P, Seweryniak D, Siem S, Vondrasek RC, Wiedenhöver I. Direct decay from the superdeformed band to the yrast line in 15266Dy86. Phys Rev Lett 2002; 88:042501. [PMID: 11801113 DOI: 10.1103/physrevlett.88.042501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2001] [Indexed: 05/23/2023]
Abstract
The excitation energy, spin, and parity of the yrast superdeformed band in 152Dy have been firmly established. The evidence comes mainly from the measured properties of a 4011 keV single-step transition connecting the yrast superdeformed level fed by the 693 keV transition to the 27- yrast state. Four additional, weaker, linking gamma rays have been placed as well. The excitation energy of the lowest superdeformed band member is 10 644 keV and its spin and parity are determined to be 24+.
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Affiliation(s)
- T Lauritsen
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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37
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Fornal B, Broda R, Maier KH, Wrzesiński J, Lane GJ, Cromaz M, Macchiavelli AO, Clark RM, Vetter K, Byrne AP, Dracoulis GD, Carpenter MP, Janssens RV, Wiedenhoever I, Rejmund M, Blomqvist J. Effective charge of the (pi)h(11/2) orbital and the electric field gradient of Hg from the Yrast structure of 206Hg. Phys Rev Lett 2001; 87:212501. [PMID: 11736335 DOI: 10.1103/physrevlett.87.212501] [Citation(s) in RCA: 3] [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: 04/30/2001] [Indexed: 05/23/2023]
Abstract
The gamma-ray decay of excited states of the two-proton hole nucleus, 206Hg, has been identified using Gammasphere and 208Pb+238U collisions. The yrast states found include a T(1/2) = 92(8) ns 10(+) isomer located above the known 5(-) isomer. The B(E2;10(+)-->8(+)) strength is used to derive the quadrupole polarization charge induced by the h(11/2) proton hole. Also, the implied quadrupole moment has been used to provide an absolute scale for the electric field gradient of Hg in Hg metal.
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Affiliation(s)
- B Fornal
- Niewodniczanski Institute of Nuclear Physics, PL-31342 Cracow, Poland
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38
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Clark RM, Fallon P, Görgen A, Cromaz M, Deleplanque MA, Diamond RM, Lane GJ, Lee IY, Macchiavelli AO, Ramos RG, Stephens FS, Svensson CE, Vetter K, Ward D, Carpenter MP, Janssens RV, Wadsworth R. Very extended shapes in the A--110 region. Phys Rev Lett 2001; 87:202502. [PMID: 11690470 DOI: 10.1103/physrevlett.87.202502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2001] [Indexed: 05/23/2023]
Abstract
High-angular-momentum states in 108Cd were populated via the (64)Ni((48)Ca,4n) reaction at a beam energy of 207 MeV. Gamma rays were detected using the Gammasphere array. A rotational band has been observed with a dynamic moment of inertia and deduced lower limit of the quadrupole moment suggesting a major-to-minor axis ratio larger than 1.8:1, placing it among the most deformed structures identified in any nucleus, to date.
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Affiliation(s)
- R M Clark
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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39
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Clark ST, Hackman G, Janssens RV, Clark RM, Fallon P, Floor SN, Lane GJ, Macchiavelli AO, Norris J, Sanders SJ, Svensson CE. Empirical investigation of extreme single-particle behavior of nuclear quadrupole moments in highly collective A approximately 150 superdeformed bands. Phys Rev Lett 2001; 87:172503. [PMID: 11690269 DOI: 10.1103/physrevlett.87.172503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2001] [Indexed: 05/23/2023]
Abstract
The intrinsic quadrupole moment Q(0) of superdeformed rotational bands in A approximately 150 nuclei depends on the associated single-particle configuration. We have derived an empirical formula based on the additivity of effective quadrupole moments of single-particle orbitals that describes existing measurements from (142)Sm to (152)Dy. To further test the formula, the predicted Q(0) moments for two superdeformed bands in (146)Gd of 14.05 eb were confronted with a new measurement yielding 13.9+/-0.4 eb and 13.9+/-0.3 eb, respectively. This excellent agreement provides empirical evidence of extreme single-particle behavior in highly deformed, collective systems.
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Affiliation(s)
- S T Clark
- Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, USA
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40
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Svensson CE, Macchiavelli AO, Juodagalvis A, Poves A, Ragnarsson I, Aberg S, Appelbe DE, Austin RA, Baktash C, Ball GC, Carpenter MP, Caurier E, Clark RM, Cromaz M, Deleplanque MA, Diamond RM, Fallon P, Furlotti M, Galindo-Uribarri A, Janssens RV, Lane GJ, Lee IY, Lipoglavsek M, Nowacki F, Paul SD, Radford DC. Superdeformation in the N = Z nucleus 36Ar: experimental, deformed mean field, and spherical shell model descriptions. Phys Rev Lett 2000; 85:2693-2696. [PMID: 10991210 DOI: 10.1103/physrevlett.85.2693] [Citation(s) in RCA: 3] [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: 05/08/2000] [Indexed: 05/23/2023]
Abstract
A superdeformed rotational band has been identified in 36Ar, linked to known low-spin states, and observed to its high-spin termination at Ipi = 16(+). Cranked Nilsson-Strutinsky and spherical shell model calculations assign the band to a configuration in which four pf-shell orbitals are occupied, leading to a low-spin deformation beta(2) approximately 0.45. Two major shells are active for both protons and neutrons, yet the valence space remains small enough to be confronted with the shell model. This band thus provides an ideal case to study the microscopic structure of collective rotational motion.
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Affiliation(s)
- CE Svensson
- Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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41
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Ertürk S, Twin PJ, Appelbe DE, Fallon P, Beausang CW, Asztalos S, Krüken R, Lauritsen T, Lee IY, Macchiavelli AO, Stephens FS. New Superdeformed Bands in 150Gd. The Nucleus 2000. [DOI: 10.1007/978-1-4615-4257-5_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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42
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Krücken R, Hackman G, Deleplanque MA, Janssens RV, Lee IY, Ackermann D, Ahmad I, Amro H, Asztalos S, Blumenthal DJ, Carpenter MP, Clark RM, Diamond RM, Fallon P, Fischer SM, Herskind B, Khoo TL, Lauritsen T, Macchiavelli AO, MacLeod RW, Nisius D, Schmid GJ, Stephens FS, Vetter K. Test of Delta I=2 staggering in the superdeformed bands of 194Hg. Phys Rev C Nucl Phys 1996; 54:R2109-R2113. [PMID: 9971639 DOI: 10.1103/physrevc.54.r2109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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43
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LaFosse DR, Sarantites DG, Baktash C, Asztalos S, Brinkman MJ, Cederwall B, Clark RM, Devlin M, Fallon P, Gross CJ, Jin H, Lee IY, Lerma F, Macchiavelli AO, MacLeod R, Rudolph D, Stracener DW, Yu C. Search for hyperdeformation in 146,147Gd. Phys Rev C Nucl Phys 1996; 54:1585-1588. [PMID: 9971503 DOI: 10.1103/physrevc.54.1585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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44
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Schnare H, LaFosse DR, Fossan DB, Hughes JR, Vaska P, Hauschild K, Hibbert IM, Wadsworth R, Janzen VP, Radford DC, Mullins SM, Beausang CW, Paul ES, DeGraaf J, Lee I, Macchiavelli AO, Afanasjev AV, Ragnarsson I. Smooth termination of intruder bands in 51109Sb. Phys Rev C Nucl Phys 1996; 54:1598-1609. [PMID: 9971506 DOI: 10.1103/physrevc.54.1598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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45
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Tomasi D, Niello JO, Pacheco AJ, Abriola D, Testoni JE, Macchiavelli AO, Capurro OA, DiGregorio DE, Martí GV, Urteaga I. One and two charge stripping reactions in the 12C+197Au and 16O+197Au systems at large distances. Phys Rev C Nucl Phys 1996; 54:1282-1290. [PMID: 9971463 DOI: 10.1103/physrevc.54.1282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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46
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Baldsiefen G, Stoyer MA, Cizewski JA, McNabb DP, Younes W, Becker JA, Bernstein LA, Brinkman MJ, Farris LP, Henry EA, Hughes JR, Kuhnert A, Wang TF, Cederwall B, Clark RM, Deleplanque MA, Diamond RM, Fallon P, Lee IY, Macchiavelli AO, Oliveira J, Stephens FS, Burde J, Vo DT, Frauendorf S. Shears bands in 193Pb. Phys Rev C Nucl Phys 1996; 54:1106-1116. [PMID: 9971443 DOI: 10.1103/physrevc.54.1106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Babu BR, Zhu SJ, Ramayya AV, Hamilton JH, Peker LK, Wang MG, Ginter TN, Kormicki J, Ma WC, Cole JD, Aryaeinejad R, Butler-Moore K, Dardenne YX, Drigert MW, Ter-Akopian GM, Oganessian YT, Rasmussen JO, Asztalos S, Lee IY, Macchiavelli AO, Chu SY, Gregorich KE, Mohar MF, Prussin S, Stoyer MA, Lougheed RW, Moody KJ, Wild JF. Identification of gamma transitions in 147Ba, 149Ce, and 151,153Nd. Phys Rev C Nucl Phys 1996; 54:568-571. [PMID: 9971379 DOI: 10.1103/physrevc.54.568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hauschild K, Wadsworth R, Clark RM, Hibbert IM, Fallon P, Macchiavelli AO, Fossan DB, Schnare H, Thorslund I, Nolan PJ, Semple AT, Walker L. Triaxial bands in 133Ce. Phys Rev C Nucl Phys 1996; 54:613-619. [PMID: 9971384 DOI: 10.1103/physrevc.54.613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Vo DT, Kelly WH, Wohn FK, Hill JC, Vary JP, Deleplanque MA, Stephens FS, Diamond RM, Oliveira JR, Macchiavelli AO, Becker JA, Henry EA, Brinkman MJ, Stoyer MA, Draper JE. Reply to "Comment on 'Very weak gamma transitions in the epsilon / beta + decay of 68Ga' ". Phys Rev C Nucl Phys 1996; 54:441-442. [PMID: 9971363 DOI: 10.1103/physrevc.54.441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Rudolph D, Gross CJ, Akovali YA, Baktash C, Döring J, Durham FE, Hua P, Johns GD, Korolija M, LaFosse DR, Lee IY, Macchiavelli AO, Rathbun W, Sarantites DG, Stracener DW, Tabor SL, Afanasjev AV, Ragnarsson I. Shell-model influence in the rotational nucleus 86Mo. Phys Rev C Nucl Phys 1996; 54:117-124. [PMID: 9971325 DOI: 10.1103/physrevc.54.117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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