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

Abstract

Abstract.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 neutronrich 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 130 Cd 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.

Charge-Exchange Excitations with Skyrme Interactions in a Separable Approximation

“…About 99% of the G-T strength distribution is located below 30 MeV with respect to the parent ground state. Taking into account the QRPA tensor correlations within our approach 49) can improve the results. The tensor correlations can shift up about 10% of the G-T strength to the higher energy region in the case of 90 Zr and 208 Pb.…”

“…The tensor correlations can shift up about 10% of the G-T strength to the higher energy region in the case of 90 Zr and 208 Pb. 15), 16), 49) The evolution of the SD strength is shown in Figs. 9 and 10.…”