SPECTROSCOPIC STUDIES OF SOME sd pf SHELL NUCLEI

Abstract

and#947;-ray spectroscopy of the light mass region has seen renewed interest in the past two decades due to the access to certain exotic phenomena that were thought to be exclusive only to higher mass nuclei. 49V has nine nucleons in 1f7/2 shell, which is large enough to lead to collective excitations. A significant amount of work has already been reported on 49V. However, certain aspects of the nucleus structure were still unknown. So, the first work of this thesis deals with the evolution of nuclear structure along the various bands of 49V. In this regard, an experiment was carried out using INGA to populate 49V through 48 MeV alpha induced reaction. Rigorous analysis has been carried out to reinvestigate the level structure and measure the lifetimes of a few levels using the Doppler Shift Attenuation Method. Large basis shell model (LBSM) calculations were carried out also to understand the underlying microscopic structure of the levels. K mixing between different bands has been established from one-nucleon-transfer spectroscopic factor calculations and total Routhian surface calculations. newlineAnother interesting aspect of nuclear structure, the isospin symmetry, forms the second study of this thesis. Although experimental evidence of isospin symmetry violation are profound, the nature and extent of this violation are still not very well understood. Therefore, to understand this, calculations were carried out to estimate the isospin mixing amplitudes in certain states of a few N = Z upper-sd shell nuclei. These states were identified as mixed isospin states by the presence of isospin-forbidden E1 transitions between them. Standard two-level mixing formalism was used in a semi-empirical approach to obtain the isospin mixing probability. Results indicate a role of isospin non-conserving interactions in the violation of the isospin symmetry for a few nuclei. Further investigations are required to establish the claim conclusively. newline