LIFETIMES NEAR THE BANDHEAD OF A SHEARS BAND IN PB-198

Subpicosecond lifetimes of states near the bandhead of an M1 band in P b-198 have been measured with the recoil-distance Doppler-shift techni que using the Gammasphere array and the Cologne plunger. The deduced B (MI) values are in agreement with the predictions of the tilted axis c ranking (TAC) model. Their spin dependence continues the trend set by recently published B(MI) values for the high spin states in this band. The emerging picture gives strong support to the concept of ''magneti c rotation,'' an alternative mode for the generation of rotational spe ctra in nuclei. [S0556-2813(98)50710-8].