Nucleon-nucleon correlation functions from different interactions in comparison

TL;DR

This study compares nucleon-nucleon correlation functions derived from different high-precision nuclear interactions to evaluate how well these functions reflect the underlying scattering data and their sensitivity to various force models.

Contribution

It provides a detailed analysis of nucleon-nucleon correlation functions across multiple interactions, highlighting the effects of partial waves and channel coupling on the results.

Findings

Correlation functions vary up to 5.9% for nn systems between models.

Differences are up to 1.8% for np and 1.4% for pp systems.

The study assesses the sensitivity of correlation functions to different nuclear potentials.

Abstract

Correlation functions as they can be observed in heavy-ion collisions using the femtoscopy technique are a powerful tool to study the interaction among different baryons or mesons. Specifically, the multi-nucleon correlation functions have been under intense experimental and theoretical investigation in the recent years. Due to the interest of using this observable as an input in the construction of potentials between hadrons we revisit the nucleon-nucleon correlation function and calculate it using different nuclear interactions at high precision. Since the nucleon-nucleon potential is determined to reproduce the two-nucleon scattering data, we would like to critically evaluate the amount of this information captured by the correlation function. We study the dependence of the correlations on the nuclear force giving detailed insights into the calculations, in particular the convergence behavior in the partial waves. The coupling between the different partial-wave channels is taken into account and the relevance of this effect is quantified. To make contact with precedent studies the results based on the Argonne V18 interaction are presented. Then we consider also the Norfolk NV2-IIa and NV2-IIb chiral EFT interactions. The analysis of the differences between the correlations of the various interactions shows that for momenta between 0 and 500 MeV there are variations of up to 5.9 % for the $nn$ system, of up to 1.8 % for the $np$ system, and of 1.4 % for the $pp$ system.