Analysis of realistic and empirical multipole interactions for shell-model calculations

TL;DR

This paper analyzes the multipole components of realistic and empirically-corrected nucleon-nucleon interactions in shell-model calculations, emphasizing the role of different force components and their medium renormalization.

Contribution

It provides a detailed analysis of the multipole parts of NN interactions, highlighting the dominance of the central component and the effects of medium renormalization, which was less explored in previous studies.

Findings

Central component dominates the leading multipoles.

Tensor and spin-orbit contributions are analyzed for their roles.

Renormalization effects depend on the interaction's cutoff and convergence.

Abstract

We perform analysis of realistic nucleon-nucleon interactions, as well as of empirically-corrected interactions, fitted to reproduce in detail the spectroscopic data in p and sd shells. We focus on the multipole part of the interactions, contrary to previous studies of that type which focused on monopole parts. We analyze how the different parts of the NN force (tensor, spin-orbit and central) contribute to the leading multipoles of the interaction and how do they renormalize in medium. We show that the leading coherent terms of the realistic and effective interactions are dominated by the central component as expected from their schematic operator structure. Convergence and cutoff dependence of multipole Hamiltonians is also discussed.