Revisiting band structures in ¹¹⁸Xe nucleus via in-beam -ray spectroscopy

The neutron deficient Xe nuclei with A approximate to 120 are predicted to have strong octupole correlation at low spins. In the present study, an attempt was made to improve upon the level scheme and also to examine the signatures of octupole correlation in Xe-118 via high spin gamma-ray spectroscopy. High spin states in Xe-118 have been populated via the Nb-93(Si-28, p2n) Xe-118 fusion-evaporation reaction at a beam energy of 115 MeV provided by the 15 UD pelletron accelerator facility at IUAC, New Delhi. In the experiment, seven new gamma-transitions have been found and placed appropriately in the level scheme. A theoretical study using the triaxial projected shell model (TPSM) approach suggests that the first bandcrossing is due to the alignment of two neutrons, and a parallel band tracking the yrast configuration is the gamma-band built on the two-quasiparticle state. Enhanced E1 transition rates measured between opposite parity bands involving vh(11/2) and vd(5/2) orbitals having Delta j = Delta l = 3 indicate the presence of octupole correlation in this nucleus.