Study of [formula omitted]/EC-decay properties of [formula omitted] shell nuclei using nuclear shell model

Abstract

Our study employs the nuclear shell model to systematically compute the half-lives of β-decay for nuclei in the mass range of A=18−39, encompassing the majority of sd shell nuclei. This analysis utilizes the USDB and SDNN Hamiltonians. The theoretical outcomes contain calculations of various parameters such as Q-values, half-lives, excitation energy, logft values, and branching ratios. We explore these results with axial–vector coupling constant for weak interactions, denoted as gA(=1.27), and κ value (=6289). We perform calculations of Gamow Teller matrix elements for 116 decay processes to calculate the quenching factor; we found a quenching factor of q=0.794±0.05 for the USDB interaction and q=0.815±0.04 for the SDNN interaction. We have also calculated superallowed transitions 0+→0+ for seven nuclei. Further, we have also included the electron capture phase space factor for the required nuclei to calculate the half-lives. This inclusion leads to small contribution in results, particularly for nuclei where electron capture (EC) plays a significant role. The overall results are in agreement with the experimental data.