The scissors mode in the presence of a neutron skin

The effect of a neutron skin on the collective scissors mode in very neutron-rich nuclei is investigated. The algebraic approach is used to show that the development of a neutron skin can give rise to an additional low-lying mode involving out-of-phase motion of the skin neutrons against the remaining nucleons of the core. This “soft” scissors mode represents the analogue of the soft dipole mode already postulated to occur in such nuclei.