2000/12/11 by K. Langanke, E. Kolbe, D. J. Dean
Physics and Astronomy · #Astro and Planetary Science #Neutrino Physics Research #Nuclear physics research studies #nucl-th
paper · pdf · doi:10.1103/physrevc.63.032801
published as Phys.Rev. C63 (2001) 032801
arxiv created 2000/12/11 · openalex publication_date 2001/02/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a new model to calculate stellar electron capture rates for neutron-rich nuclei. These nuclei are encountered in the core collapse of a massive star. Using the shell model Monte Carlo approach, we first calculate the finite temperature occupation numbers in the parent nucleus. We then use these occupation numbers as a starting point for calculations using the random phase approximation (RPA). Using the RPA approach, we calculate electron capture rates including both allowed and forbidden transitions. Such a hybrid model is particularly useful for nuclei with proton numbers Z<40 and neutron numbers N>40, where allowed Gamow-Teller transitions are only possible due to configuration mixing by the residual interaction and by thermal unblocking of pf-shell single-particle states. Using the even germanium isotopes ^68\ensuremath-76Ge as examples, we demonstrate that the configuration mixing is strong enough to unblock the Gamow-Teller transitions at all temperatures relevant to core-collapse supernovae.