Lifetime measurements and magnetic rotation in107Ag

Abstract

The excited states in ${}^{107}$Ag were populated through the heavy-ion fusion evaporation reaction ${}^{100}$Mo (${}^{11}$B, 4$n$) ${}^{107}$Ag at a beam energy of 46 MeV. Lifetimes of high-spin states in ${}^{107}$Ag have been measured through the Doppler shift attenuation method. The deduced $B(M1)$ values, gradually decreasing with increasing spin, clearly demonstrate that both the yrast positive-parity band and the yrast negative-parity band in ${}^{107}$Ag are magnetic rotation bands. Furthermore, experimental deduced $B(M1)$ values for the yrast positive-parity band are compared with the predictions of the particle rotor model. The approximate agreement between theoretical calculations and experimental results further confirms the mechanism of magnetic rotation for the yrast positive-parity band. In addition, a systematic investigation shows the evolution of the magnetic rotation mechanism in the $A\ensuremath{\approx}110$ mass region.