ON THE SEARCH FOR THE SCISSORS MODE

Abstract

Results from quasiparticle RPA calculations on 1+ excitations in deformed nuclei, including M1 transition densities and (e, e′) form factors, are compared to the microscopic representation of the scissors state of the two-rotor model. Although this state is too collective, especially in heavy nuclei, it fragments mainly over the low lying orbital M1 excitations, which can be interpreted as a manifestation of a weakly collective scissors mode. The experimentally observed strongest M1 excitation has the same leading components in the wave function as the scissors state, the largest overlap with it, and similar transition density and form factor. Although the scissors mode is more pronounced in heavy deformed nuclei, the strong low lying orbital M1 excitations in lighter nuclei represent a better approximation to it, because the scissors state is less collective in light nuclei.