Total Routhian surface calculations to study the abrupt band termination phenomenon in I-121,I-123

摘要

The phenomenon of abrupt band termination in I-121,I-123 has been revisited in the light of total Routhian surface (TRS) calculations. Both axial (beta) and nonaxial (gamma) quadrupole deformation parameters have been estimated for the negative parity states. The calculation has also been extended for I-119 and the theoretical result has been compared with the available experimental information. The calculated transition quadrupole moments (Q(t)) are matching nicely upto (h) over bar omega approximate to 0.25 MeV. The noncollective oblate shapes become yrast at higher angular frequency in I119-123. At lower spin, all of these nuclei exhibit a collective prolate shape. This sudden change in shape at I approximate to 20 (h) over bar is indicative of the loss of collectivity at (h) over bar omega approximate to 0.35-0.40 MeV.