Microscopic calculations of stellar weak interaction rates and energy losses for fp- and fpg-shell nuclei

Abstract

Nuclear weak interaction rates for fp- and fpg-shell nuclei in stellar matter and the associated energy losses are calculated using a modified form of proton–neutron quasiparticle random phase approximation model with separable Gamow–Teller forces. The stellar weak rates are calculated over a wide range of densities (10 ⩽ ρY e (g cm −3) ⩽ 10 11) and temperatures (10 7 ⩽ T (K) ⩽ 30 × 10 9). We also calculate the probability of particle emission processes in stellar environment. We present an extensive compilation of weak interaction rates in stellar matter calculated over a wide temperature–density grid and over a large mass range. The calculated capture and decay rates take into consideration the latest compilations of experimental energy levels and ft values. This paper is a follow up of our calculations introduced earlier [Eur. Phys. J. A 5 (1999) 337]. We have calculated stellar weak interaction rates for a total of 650 nuclei in the mass range A = 40–100. These also include many important neutron-rich nuclei which play an important role in the evolution process of stellar collapse.