Electromagnetic B (E2) transition strengths along the yrast negative-parity band of 113I

The mean lifetimes of seven states in 113I excited via the reaction 58Ni(58Ni,3p) at a beam energy of 210 MeV were measured for the first time by means of the recoil-distance Doppler-shift technique. The lifetimes were determined in coincidence mode within the framework of the differential decay-curve method. The quadrupole deformation derived from the B(E2) values at the bottom of the negative-parity yrast band confirms the predictions of previous TRS calculations. At higher excitation energy along the yrast line, the experimental B(E2) transition strengths indicate an apparent loss of collectivity with increasing spin. A three-band mixing calculation provides an overall description of these strengths.