Lifetime measurement of candidate chiral doublet bands in theRh103,104isotopes with the recoil-distance Doppler-shift method in inverse kinematics

Abstract

Lifetimes of chiral candidate structures in $^{103,104}\mathrm{Rh}$ were measured using the recoil distance Doppler-shift method. The Gammasphere detector array was used in conjunction with the Cologne plunger device. Excited states of $^{103,104}\mathrm{Rh}$ were populated by the ${}^{11}\mathrm{B}({}^{96}\mathrm{Zr},4n){}^{103}\mathrm{Rh}$ and ${}^{11}\mathrm{B}({}^{96}\mathrm{Zr},3n){}^{104}$Rh fusion-evaporation reactions in inverse kinematics. Three and five lifetimes of levels belonging to the proposed chiral doublet bands are measured in $^{103}\mathrm{Rh}$ and $^{104}\mathrm{Rh}$, respectively. The previously observed even-odd spin dependence of the $B(M1)/B(E2)$ values is caused by the variation in the $B(E2)$ values, whereas the $B(M1)$ values decrease as a function of spin.