High-momentum antisymmetrized molecular dynamics compared with tensor-optimized shell model for strong tensor correlation

TL;DR

This paper introduces high-momentum antisymmetrized molecular dynamics (HM-AMD), a new method that effectively captures strong tensor correlations in nuclei by incorporating large relative momenta among nucleon pairs, comparable to tensor-optimized shell model results.

Contribution

The paper presents HM-AMD, a novel approach that models tensor correlations via high-momentum components, matching the tensor effects of the tensor-optimized shell model in finite nuclei.

Findings

HM-AMD reproduces tensor matrix elements similar to TOSM.

High-momentum components in HM-AMD effectively mimic 2p-2h excitations.

Results demonstrate equivalence of HM-AMD and TOSM in describing tensor correlations.

Abstract

We treat the tensor correlation in antisymmetrized molecular dynamics (AMD) including large-relative-momentum components among nucleon pairs for finite nuclei. The tensor correlation is described by using large imaginary centroid vectors of Gaussian wave packets for nucleon pairs with opposite directions, which makes a large relative momentum. We superpose the AMD basis states, in which one nucleon pair has various relative momenta for all directions; this new method is called "high-momentum AMD" (HM-AMD). We show the results for $^4$He using the effective interaction having a strong tensor force. It is found that HM-AMD provides a large tensor matrix element comparable to the case of the tensor-optimized shell model (TOSM), in which the two-particle-two-hole (2p-2h) excitations are fully included to describe the tensor correlation. The results of two methods agree with each other at the level of the Hamiltonian components of $^4$He. This indicates that in HM-AMD the high-momentum components described by the imaginary centroid vectors of the nucleon pair provide the equivalent effect of the 2p-2h excitations for the tensor correlation.