Indication of γ -vibration in 123,125,127I

Abstract

High spin states in 127I were populated via 124Sn(7Li, 4nγ) fusion-evaporation reaction with Ebeam = 33 MeV. Level scheme of 127I has been updated by placing new γ-rays and also confirming the spin/parity of several energy levels. Two new levels at Ex = 2628 and 3199 keV have been identified which are found to decay in the negative parity πh11/2 band. These two states and two earlier reported states at 3502 and 3989 keV have been interpreted as the γ-vibrational states on the basis of their decay pattern. Two positive parity three-quasiparticle bands above Iπ = 23/2+ states at 2901 and 3060 keV have been identified to be a possible candidate of the chiral band. A comparison in the isotopic and isotonic chains reveals the possible existence of γ-vibration and chiral rotation in 123−127I.