Advanced search
Start date
Betweenand
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Gamow-Teller transitions to Zr-93 via the Nb-93(t, He-3 + gamma) reaction at 115 MeV/u and its application to the stellar electron-capture rates

Full text
Author(s):
Show less -
Gao, B. [1, 2, 3, 4] ; Zegers, R. G. T. [5, 2, 3] ; Zamora, J. C. [6, 2, 3] ; Bazin, D. [5, 2] ; Brown, B. A. [5, 2, 3] ; Bender, P. [7] ; Crawford, H. L. [8] ; Engel, J. [9] ; Falduto, A. [3, 10] ; Gade, A. [5, 2, 3] ; Gastis, P. [3, 10] ; Ginter, T. [2] ; Guess, C. J. [11] ; Lipschutz, S. [5, 2, 3] ; Macchiavelli, A. O. [8] ; Miki, K. [12] ; Ney, E. M. [9] ; Longfellow, B. [5, 2] ; Noji, S. [2, 3] ; Pereira, J. [2, 3] ; Schmitt, J. [5, 2, 3] ; Sullivan, C. [5, 2, 3] ; Titus, R. [5, 2, 3] ; Weisshaar, D. [2]
Total Authors: 24
Affiliation:
Show less -
[1] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000 - Peoples R China
[2] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 - USA
[3] Michigan State Univ, Joint Inst Nucl Astrophys, Ctr Evolut Elements, E Lansing, MI 48824 - USA
[4] Inst Modern Phys, 509 Nanchang Rd, Lanzhou 730000 - Peoples R China
[5] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 - USA
[6] Univ Sao Paulo, Inst Fis, BR-05508090 Sao Paulo - Brazil
[7] Univ Massachusetts, Dept Phys, Lowell, MA 01854 - USA
[8] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 - USA
[9] Univ North Carolina Chapel Hill, Dept Phys & Astron, Chapel Hill, NC 27599 - USA
[10] Cent Michigan Univ, Mt Pleast, MI 48859 - USA
[11] Swarthmore Coll, Dept Phys & Astron, Swarthmore, PA 19081 - USA
[12] Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578 - Japan
Total Affiliations: 12
Document type: Journal article
Source: Physical Review C; v. 101, n. 1 JAN 10 2020.
Web of Science Citations: 0
Abstract

Electron-capture reactions play important roles in the late evolution of core-collapse supernovae. The electroncapture rates used in astrophysical simulations rely on theoretical calculations which have to be tested against and guided by experimental data. We report on the measurement of the Gamow-Teller strength distribution of the odd-mass nucleus Nb-93 via the (t, He-3 gamma) charge-exchange reaction at a beam energy of 115 MeV/u. The Gamow-Teller strength distributions were extracted up to an excitation energy in Zr-93 of 10 MeV. The results were compared with shell-model and quasiparticle random-phase approximation (QRPA) calculations. The theoretical calculations fail to describe the details of the strength distribution, but estimate reasonably well the integrated Gamow-Teller transition strength. Electron-capture rates derived from the measured and theoretical strength distributions match reasonably well, especially at the higher stellar densities of importance for deleptonization during the collapse of the stellar core, since the electron-capture Q value is close to zero and the Fermi energy sufficiently high to ensure that the details of the strength distribution do not have a strong impact on the derived rates. At stellar densities in excess of 10(9)g/cm(3), the electron-capture rate based on a single-state approximation used in astrophysical simulations is slightly higher than the rates based on the data and the shell-model and QRPA calculations, likely due to the fact that the approximation includes temperature-dependent effects, which increase the rates. However, the difference is much smaller than that observed in recent studies of nuclei with Z < 40 near N = 50, suggesting that the single-state approximation does not account for Pauli-blocking effects for nuclei with Z < 40 that are much stronger than those for Nb-93 with Z = 41. (AU)

FAPESP's process: 18/04965-4 - Study of structure and nuclear reactions induced by exotic nuclei using active targets
Grantee:Juan Carlos Zamora Cardona
Support type: Scholarships in Brazil - Post-Doctorate