Nature of the scissors mode in nuclei near shell closure: the tellurium isotope chain

Quasiparticle random-phase approximation calculations, where rotational, translational and Galilean invariance are restored selfconsistently by using separable effective forces, are presented for the ground state dipole response in the even-mass isotopes 122−130Te. The simultaneous description of E1 and M1 transitions permits a direct comparison with nuclear resonance fluorescence experiments. The extracted properties of the scissors mode reveal a considerable complexity in these near closed-shell nuclei: neither approaches successful in deformed nuclei nor a two-phonon picture suggested near shell closures nor the interacting boson model can fully account for the data.