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In a recent study by Cole et al. [A. L. Cole et al., Phys. Rev. C 86 (2012) 015809], it was concluded that quasi-particle random phase approximation (QRPA) calculations show larger deviations and overestimate the total experimental Gamow–Teller (GT) strength. It was also concluded that QRPA calculated electron capture rates exhibit larger deviation than those derived from the measured GT strength distributions. The main purpose of this study is to probe the findings of the Cole et al. paper. This study gives useful information on the performance of QRPA-based nuclear models. As per simulation consequences, the electron capture (EC) rates on medium-heavy nuclei have a key impact on decreasing the ratio of electron-to-baryon of the stellar matter during the late stages of stars formation. Stellar model mostly rely on EC rates tables, based on the theoretical approaches, which should be tested against the available measured data.
In this work we present the computation of allowed charge-changing transitions for odd-A ($^{45}$Sc and ${}^{55}$Mn) fp-shell nuclei by using the deformed pn-QRPA models. The GT transition strength is compared with theoretical (including shell and other QRPA models) and measured charge-changing reaction results. For stellar applications the corresponding electron captures (EC) rates are computed and compared with previous theoretical and measured results. It was observed that our results are in good accordance with measured data. At higher stellar temperature calculated EC rates by pn-QRPA are higher than the independent particle model and shell model rates. It was further concluded that at low temperature and high density region the positron emission rates can be neglected.
