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 D(E2) transition rates show a marked decrease with increasing spin. Cranking and semiclassical model calculation suggest that the structure has the character of a shears-type band resulting from the coupling of g_9/2 proton holes to aligned pairs of h_11/2and g_7/2 neutron particles. This is the first clear evidence for the phenomenon of "antimagnetic" rotation in nuclei.