Quenching of Gamow-Teller strength due to tensor correlations inZr90andPb208

Abstract

We performed self-consistent Hartree-Fock plus random-phase approximation (HF+RPA) calculations for charge-exchange ${1}^{+}$ states in $^{90}\mathrm{Zr}$ and $^{208}\mathrm{Pb}$ by using Skyrme interactions with tensor terms. We employed a parameter set in which the tensor terms are added to the SGII interaction. It is pointed out that Gamow-Teller (GT) states can couple strongly with the spin-quadrupole (SQ) ${1}^{+}$ states in the high-energy region above ${E}_{x}=30$ MeV due to the tensor interactions. As a result of this coupling, more than $10%$ of the GT strength is shifted to the energy region above 30 MeV, and the main GT peak is moved 2 MeV downward. At the same time, the main SQ ${1}^{+}$ peak is moved upward by more than 10 MeV due to the tensor correlations. Schematic separable interactions are proposed to elucidate the quenching mechanism induced by the tensor interaction on the GT state.