Tensor Correlation in 4He and Its Effect on the Doublet Splitting in 5He

Abstract

We investigate the role of tensor correlation on the structures of 4 He and its effect on the doublet splitting in 5 He. We perform a configuration mixing calculation in the shell model type bases to represent the tensor correlation for 4 He. It is found that our model describes the characteristics of the tensor correlation, which is represented by an admixture of the 0s 1/2 configuration with a spatially modified 0p 1/2 orbit. For 5 He, we solve a coupled OCM equation for an extended 4 He+n model, while taking into account the tensor correlation in the 4 He cluster. It is shown that the tensor correlation produces the Pauli blocking, in particular, for the J = 1/2 -state, and its effect causes about half of the p-wave doublet splitting in 5 He. This indicates that the strength of the effective spin-orbit interaction should be reduced by about half from the conventional one. We obtain a reliable 4 He-n interaction, including the tensor correlation, which further improves the behavior of the d-and f -wave phase shifts in the 4 He+n system.