Executive Summary : | Recent experimental development of radioactive ion beam facilities has provided an opportunity to study exotic nuclei near proton and neutron drip lines, which can decay through beta-, beta+, and electron capture decay modes. To study these nuclei, theoretical novel approaches have been developed, such as ab initio approaches and large-scale shell models. Experiments have been conducted worldwide using RIB facilities to measure single and double beta-decay half-lives, logft values, Q-values, branching ratios, and energy spectra of exotic nuclei. Recent studies show that beta decays and electron capture reactions play a crucial role in nuclear physics and astrophysical phenomena like supernovae explosions and nucleosynthesis. This project focuses on the theoretical study of single and double Gamow-Teller transition strengths for different regions of the nuclear chart. The GT transition is a nuclear week interaction process used to study the structure of atomic nuclei. Many experiments have been performed to observe first and second forbidden beta decays in the literature, motivating the study of these nuclei using modern large-scale shell model calculations. |