Lepton capture rates due to isotopes of vanadium in astrophysical environment

Abstract

Lepton (electron and positron) capture rates on iron-regime nuclei are an essential element for modeling the late stages of progression of massive stars that become core collapse and thermonuclear supernova. As per previous simulation studies, lepton capture (LC) rates on isotopes of vanadium are believed to have a substantial effect in regulating the Ye (lepton to baryon fraction) during the final evolutionary phases. The present work involves the calculation of lepton capture rates for 22 isotopes of vanadium by making use of the proton-neutron (pn-) quasiparticle random phase approximation (QRPA) model. The covered mass range is from A = 43 to 64. The LC rates have been computed over stellar densities ranging from $10^{1}$ to $10^{11}$ (g/cm3) and for the temperature range $10^{7} - 3 \times 10^{10}$ (K). A comparison of our calculated LC rates to the rates computed using other models (IPM and LSSM) has also been presented. As compared to the rates calculated by other models, pn-QRPA rates at high temperature ( $3 \times 10^{10}$ K) are larger by up to 1-2 orders of magnitude.