Gamow-Teller resonances and a separable approximation for Skyrme tensor interactions

A finite rank separable approximation for the quasiparticle random phase approximation (QRPA) with Skyrme interactions is applied to study properties of the Gamow-Teller (GT) resonances in the neutron-rich Cd isotopes. This approximation enables one to reduce considerably the dimension of matrix that must be diagonalized to perform QRPA calculations in a very large configuration space. Our results from the SGII Skyrme interaction with the tensor interactions and the density-dependent zero-range pairing interaction show that the GT distribution is noticeably modified when the tensor correlations are taken into account. In particular, for 130Cd the dominant peak is moved 3.6 MeV downward and 10% of the GT distribution is shifted to the high excitation energy region near E=50MeV