Tensor Force Effect on Pairing Correlations for the Gamow-Teller Transition in Ca-42, Ti-46 and O-18

초록

We investigate the tensor force (TF) effect on the Gamow-Teller (GT) transition strength distributions in Ca-42, Ti-46 and O-18, which are known to have strong low-energy GT states, so called, the low energy super GT (LeSGT) transition, peculiar to the nuclei retaining a neutron number N = Z + 2. The TF is explicitly taken into account in the pairing channels of the residual interaction on top of the mean field described by a deformed Woods-Saxon potential. The pairing matrix elements (PMEs) comprising isoscalar and isovector parts, which consistently describe both the ground and the GT excited states, are calculated by the Bruckner G-matrix based on the charge dependent (CD) Bonn potential. By switching on and off the TF in the PMEs, we deduce meaningful correlations between the TF and the GT strength distributions. It is found that the attractive TF affects not only the ground state but also plays a crucial role of shifting the main GT peak to low-excitation energy region leading to the LeSGT.

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