β-DECAY OF KEY TITANIUM ISOTOPES IN STELLAR ENVIRONMENT

Abstract

Amongst iron regime nuclei, β-decay rates on titanium isotopes are considered to be important during the late phases of evolution of massive stars. The key β-decay isotopes during presupernova evolution were searched from available literature and a microscopic calculation of the decay rates were performed using the proton–neutron quasiparticle random phase approximation (pn-QRPA) theory. As per earlier simulation results, electron capture and β-decay on certain isotopes of titanium are considered to be important for the presupernova evolution of massive stars. Earlier the stellar electron capture rates and neutrino energy loss rates due to relevant titanium isotopes were presented. In this paper we finally present the β-decay rates of key titanium isotopes in stellar environment. The results are also compared against previous calculations. The pn-QRPA β-decay rates are bigger at high stellar temperatures and smaller at high stellar densities compared to the large scale shell model results. This study can prove useful for the core-collapse simulators.