Evidence for a New Type of Shears Mechanism in 106Cd

Lifetimes of states in the lowest lying positive parity band in 106Cd have been measured using the Doppler shift attenuation method. The deduced B(E2) transition rates show a marked decrease with increasing spin. Cranking and semiclassical model calculations suggest that the structure has the character of a shears-type band resulting from the coupling of g9/2 proton holes to aligned pairs of h11/2 and g7/2 neutron particles. This is the first clear evidence for the phenomenon of “antimagnetic” rotation in nuclei.