β+ Gamow-Teller Transition Strengths from 46Ti and Stellar Electron-Capture Rates

被引:25
|
作者
Noji, S. [1 ,2 ]
Zegers, R. G. T. [1 ,2 ,3 ]
Austin, Sam M. [1 ,2 ,3 ]
Baugher, T. [1 ,3 ]
Bazin, D. [1 ]
Brown, B. A. [1 ,3 ]
Campbell, C. M. [4 ]
Cole, A. L. [5 ]
Doster, H. J. [1 ,3 ]
Gade, A. [1 ]
Guess, C. J. [6 ,7 ]
Gupta, S. [8 ]
Hitt, G. W. [9 ]
Langer, C. [1 ,2 ]
Lipschutz, S. [1 ,3 ]
Lunderberg, E. [1 ,3 ]
Meharchand, R. [10 ]
Meisel, Z. [1 ,2 ,3 ]
Perdikakis, G. [1 ,11 ]
Pereira, J. [1 ]
Recchia, F. [1 ]
Schatz, H. [1 ,2 ,3 ]
Scott, M. [1 ,3 ]
Stroberg, S. R. [1 ,3 ]
Sullivan, C. [1 ,2 ,3 ]
Valdez, L. [1 ]
Walz, C. [1 ]
Weisshaar, D. [1 ]
Williams, S. J. [1 ]
Wimmer, K. [1 ,11 ]
机构
[1] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA
[2] Michigan State Univ, Joint Inst Nucl Astrophys, E Lansing, MI 48824 USA
[3] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA
[4] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA
[5] Kalamazoo Coll, Dept Phys, Kalamazoo, MI 49006 USA
[6] Univ Massachusetts Lowell, Dept Phys & Appl Phys, Lowell, MA 01854 USA
[7] Rowan Univ, Dept Phys & Astron, Glassboro, NJ 08028 USA
[8] Indian Inst Technol Ropar, Rupnagar 140001, Punjab, India
[9] Khalifa Univ Sci Technol & Res, Dept Appl Math & Sci, Abu Dhabi, U Arab Emirates
[10] Los Alamos Natl Lab, Neutron & Nucl Sci Grp, Los Alamos, NM 87545 USA
[11] Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA
基金
美国国家科学基金会;
关键词
WEAK-INTERACTION RATES; INTERMEDIATE-MASS NUCLEI; SHELL-MODEL DESCRIPTION; PF-SHELL; SPECTROMETER; ENERGIES; BEAM;
D O I
10.1103/PhysRevLett.112.252501
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
The Gamow-Teller strength in the beta(+) direction to Sc-46 was extracted via the Ti-46(t, He-3 + gamma) reaction at 115 MeV/u. The gamma-ray coincidences served to precisely measure the very weak Gamow-Teller transition to a final state at 991 keV. Although this transition is weak, it is crucial for accurately estimating electron-capture rates in astrophysical scenarios with relatively low stellar densities and temperatures, such as presupernova stellar evolution. Shell-model calculations with different effective interactions in the pf shell-model space do not reproduce the experimental Gamow-Teller strengths, which is likely due to sd-shell admixtures. Calculations in the quasiparticle random phase approximation that are often used in astrophysical simulations also fail to reproduce the experimental Gamow-Teller strength distribution, leading to strongly overestimated electron-capture rates. Because reliable theoretical predictions of Gamow-Teller strengths are important for providing astrophysical electron-capture reaction rates for a broad set of nuclei in the lower pf shell, we conclude that further theoretical improvements are required to match astrophysical needs.
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页数:6
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