Unblocking of the Gamow-Teller strength in stellar electron capture on neutron-rich germanium isotopes - art. no. 032801

Citation
K. Langanke et al., Unblocking of the Gamow-Teller strength in stellar electron capture on neutron-rich germanium isotopes - art. no. 032801, PHYS REV C, 6303(3), 2001, pp. 2801
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW C
ISSN journal
0556-2813 → ACNP
Volume
6303
Issue
3
Year of publication
2001
Database
ISI
SICI code
0556-2813(200103)6303:3<2801:UOTGSI>2.0.ZU;2-F
Abstract
We propose a new model to calculate stellar electron capture rates for neut ron-rich nuclei. These nuclei are encountered in the core collapse of a mas sive star. Using the shell model Monte Carlo approach, we first calculate t he finite temperature occupation numbers in the parent nucleus. We then use these occupation numbers as a starting point for calculations using the ra ndom phase approximation (RPA). Using the RPA approach. we calculate electr on capture rates including both allowed and forbidden transitions. Such a h ybrid model is particularly useful for nuclei with proton numbers Z < 40 an d neutron numbers N > 40, where allowed Gamow-Teller transitions are only p ossible due to configuration mixing by the residual interaction and by ther mal unblocking of pf-shell single-particle states. Using the even germanium isotopes Ge68-76 as examples, we demonstrate that the configuration mixing is strong enough to unblock the Gamow-Teller transitions at all temperatur es relevant to core-collapse supernovae.