The mean lifetimes of seven states in ${}^{113}\mathrm{I}$ excited via the reaction ${}^{58}\mathrm{Ni}{(}^{58}\mathrm{Ni},3p)$ 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 $B\left(E2\mathrm{}\right)\mathrm{}$ 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 $B\left(E2\mathrm{}\right)\mathrm{}$ transition strengths indicate an apparent loss of collectivity with increasing spin. A three-band mixing calculation provides an overall description of these strengths.

• Received 13 December 2002

DOI:https://doi.org/10.1103/PhysRevC.67.054306