| Texto completo | |
| Autor(es): Mostrar menos - |
Titus, E. R.
[1, 2, 3]
;
Ney, E. M.
[4]
;
Zegers, R. G. T.
[1, 2, 3]
;
Bazin, D.
[1, 2]
;
Belarge, J.
[2]
;
Bender, P. C.
[5]
;
Brown, B. A.
[1, 2, 3]
;
Campbell, C. M.
[6]
;
Elman, B.
[1, 2]
;
Engel, J.
[4]
;
Gade, A.
[1, 2, 3]
;
Gao, B.
[7]
;
Kwan, E.
[2]
;
Lipschutz, S.
[1, 2, 3]
;
Longfellow, B.
[1, 2]
;
Lunderberg, E.
[1, 2]
;
Mijatovic, T.
[2]
;
Noji, S.
[2, 3]
;
Pereira, J.
[2, 3]
;
Schmitt, J.
[1, 2, 3]
;
Sullivan, C.
[1, 2, 3]
;
Weisshaar, D.
[2]
;
Zamora, J. C.
[8]
Número total de Autores: 23
|
| Afiliação do(s) autor(es): | [1] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 - USA
[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] Univ North Carolina Chapel Hill, Dept Phys & Astron, Chapel Hill, NC 27599 - USA
[5] Univ Massachusetts, Dept Phys, Lowell, MA 01854 - USA
[6] Lawrence Berkeley Natl Lab, Berkeley, CA 94720 - USA
[7] Chinese Acad Sci, Inst Modern Phys, Lanzhou 730000, Gansu - Peoples R China
[8] Univ Sao Paulo, Inst Fis, BR-05508090 Sao Paulo - Brazil
Número total de Afiliações: 8
|
| Tipo de documento: | Artigo Científico |
| Fonte: | Physical Review C; v. 100, n. 4 OCT 22 2019. |
| Citações Web of Science: | 2 |
| Resumo | |
Background: In the late stages of stellar core collapse just prior to core bounce, electron captures on medium-heavy nuclei drive deleptonization. Therefore, simulations require the use of accurate reaction rates. Nuclei with neutron number near N = 50 above atomic number Z = 28 play an important role. Rates presently used in astrophysical simulations rely primarily on a relatively simple single-state approximation. In order to improve the accuracy of the astrophysical simulations, experimental data are needed to test the electron-capture rates and to guide the development of better theoretical models and astrophysical simulations. Purpose: The purpose of the present work was to measure the Gamow-Teller transition strength from Kr-86 to Br-86, to derive the stellar electron-capture rates based on the extracted strengths, and to compare the derived rates with rates based on shell-model and quasiparticle random-phase approximation (QRPA) Gamow-Teller strengths calculations, as well as the single-state approximation. An additional purpose was to test the impact of using improved electron-capture rates on the late evolution of core-collapse supernovae. Method: The Gamow-Teller strengths from Kr-86 were extracted from the Kr-86(t, He-3 + gamma) charge-exchange reaction at 115MeV/u. The electron-capture rates were calculated as a function of stellar density and temperature. Besides the case of Kr-86, the electron-capture rates based on the QRPA calculations were calculated for 78 additional isotopes near N = 50 above Z = 28. The impact of using these rates instead of those based on the single-state approximation is studied in a spherically symmetrical simulation of core collapse just prior to bounce. Results: The derived electron-capture rates on Kr-86 from the experimental Gamow-Teller strength distribution are much smaller than the rates estimated based on the single-state approximation. Rates based on Gamow-Teller strengths estimated in shell-model and QRPA calculations are more accurate. The core-collapse supernova simulation with electron-capture rates based on the QRPA calculations indicate a significant reduction in the deleptonization during the collapse phase. Conclusions: It is important to utilize microscopic theoretical models that are tested by experimental data to constrain and estimate Gamow-Teller strengths and derived electron-capture rates for nuclei near N = 50 that are inputs for astrophysical simulations of core-collapse supernovae and their multimessenger signals, such as the emission of neutrinos and gravitational waves. (AU) | |
| Processo FAPESP: | 18/04965-4 - Estudo da estrutura e reações nucleares induzidas por feixes radioativos usando alvo ativo |
| Beneficiário: | Juan Carlos Zamora Cardona |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |