Generalized nuclear contacts and the nucleon's momentum distributions

TL;DR

This paper extends the concept of nuclear contacts to include all partial waves and finite-range interactions, deriving relations with nucleon momentum distributions and verifying them with numerical data, highlighting the importance of short-range correlations in nuclei.

Contribution

It introduces generalized nuclear contact matrices considering all partial waves and finite-range effects, extending Tan's zero-range model to nuclear systems.

Findings

Derived new asymptotic relations between one- and two-nucleon momentum distributions.

Verified relations between nuclear contacts and momentum distributions using numerical data.

Identified the nucleon momentum range most affected by short-range correlations.

Abstract

The general nuclear contact matrices are defined, taking into consideration all partial waves and finite-range interactions, extending Tan's work for the zero range model. The properties of these matrices are discussed and the relations between the contacts and the one-nucleon and two-nucleon momentum distributions are derived. Using these relations, a new asymptotic connection between the one-nucleon and two-nucleon momentum distributions, describing the two-body short-range correlations in nuclei, is obtained. Using available numerical data, we extract few connections between the different contacts and verify their relations to the momentum distributions. The numerical data also allows us to identify the main nucleon momentum range affected by two-body short-range correlations. Utilizing these relations and the numerical data, we also verify a previous independent prediction connecting between the Levinger constant and the contacts. This work provides an important indication for the relevance of the contact formalism to nuclear systems, and should open the path for revealing more useful relations between the contacts and interesting quantities of nuclei and nuclear matter.