Evidence for “Magnetic Rotation” in Nuclei: Lifetimes of States in theM1 bands of198,199Pb

Lifetimes of states in four of the $M1\mathrm{}$ bands in ${}^{198,199}\mathrm{Pb}$ have been determined through a Doppler-shift attenuation method measurement performed using the Gammasphere array. The deduced $B\left(M1\mathrm{}\right)$ values, which are a sensitive probe of the underlying mechanism for generating these sequences, show remarkable agreement with tilted axis cranking (TAC) calculations. The results represent clear evidence for a new concept in nuclear excitations: “magnetic rotation.”