TPSM Analysis of Structural Evolution in

The structural evolution of the odd-mass nucleus 109Sb has been investigated using the Triaxial Projected Shell Model (TPSM). This nucleus, located close to the Z = 50 shell closure, serves as an ideal system for investigating the interplay between single-particle motion and collective rotation. Using angular-momentum projected quasiparticle configurations built on a triaxially deformed basis, we analyze the yrast and yrare band structures and compare the calculated energies with available experimental data. The TPSM results reproduce the observed band crossings and the overall evolution of the yrast and yrare bands reasonably well. A detailed examination of the dynamic moment of inertia, J2 and the reduced electric quadrupole transition probabilities reveals a gradual loss of collectivity with increasing spin for the yrast band, consistent with experimental observations. The present study provides a microscopic understanding of the structural evolution and decreasing collectivity in this nucleus.