Interplay between single particle and collective motion in 3840K and 43Ca nuclei

Abstract

This thesis mainly explores the exciting aspects of nuclear structure, explicitly investigating the interplay between single-particle and collective excitation modes in 38,40K and 43Ca, populated at IUAC New Delhi and INGA facility was used to detect the gammas. The level scheme of 38K has been revised above 31.67 and#956;s isomer by adding a few levels and transitions. Based on shell model results, the spin-parity of the isomeric level is confirmed and resolves the previously uncertain spin-parity assignments for most of the levels above the isomer. The shell model calculations further predict the presence of a deformed band arising from 4p-4h excitations at higher excitation energies in 38K. In of 40K, fourteen new transitions and six new levels have been added to the existing level scheme. Importantly, we confirmed or updated the spin-parity assignments for all levels above 3 MeV. The configurations of the positive and negative parity levels have been assigned from shell-model calculations. Theoretical calculations demonstrate that high-spin negative-parity states exhibit considerable configuration mixing in terms of particle partitions, suggesting the existence of collective excitations at higher excitation energies in 40K. The structural behavior of 43Ca was extended up to the band-terminating 25/2+ state by adding two new levels and seven transitions to the existing level scheme. The observed positive-parity states follow a linear relationship between J(J+1) and excitation energy up to the band-terminating states, consistent with shell-model calculations. A remarkable enhancement in the B(E2) values for a few low lying transitions due to the mixing of different mp-mh configuration, was found. Our findings indicate that low-lying states exhibit collective behavior, which gradually diminishes with increasing excitation energy, leading to a transition towards single-particle behavior. newline newline