Tensor correlations in $^4$He and $^8$Be with antisymmetrized quasi cluster model

TL;DR

This paper introduces an extended antisymmetrized quasi cluster model incorporating tensor interactions, revealing significant tensor effects in helium isotopes and their influence on nuclear structure and cluster interactions.

Contribution

The paper develops AQCM-T, a tensor-inclusive model, and proposes a new effective interaction V2m, enabling simplified treatment of tensor effects in heavier nuclei.

Findings

Tensor contributions in $^4$He are comparable to central interactions.

Tensor suppression affects short-range alpha cluster repulsion.

The model successfully describes tensor effects in $^8$Be.

Abstract

In this paper, we extend the framework of improved version of simplified method to take into account the tensor contribution ($i$SMT) and propose AQCM-T, tensor version of antisymmetrized quasi cluster model (AQCM). Although AQCM-T is phenomenological, we can treat the $^3S$-$^3D$ coupling in the deuteron-like $T=0$ $NN$-pair induced by the tensor interaction in a very simplified way, which allows us to proceed to heavier nuclei. Also we propose a new effective interaction, V2m, where the triplet-even channel of the Volkov No.2 interaction is weakened to 60% so as to reproduce the binding energy of $^4$He after including the tensor term of a realistic interaction. Using AQCM-T and the new interaction, the significant tensor contribution in $^4$He is shown, which is almost comparable the central interaction, where $D$-state mixes by 8% to the major $S$-state. The AQCM-T model with the new interaction is also applied to $^8$Be. It is found that the tensor suppression gives significant contribution to the short-range repulsion between two {\alpha} clusters.