Experimental evaluation of the nuclear neutron-proton contact

TL;DR

This paper introduces the nuclear neutron-proton contact, generalizes Tan's concept, and evaluates it using experimental data from nuclear photodisintegration, establishing a link between the Levinger constant and the contact.

Contribution

It reformulates the quasi-deuteron model and connects the Levinger constant to the neutron-proton contact, enabling its extraction from experimental data.

Findings

Neutron-proton contact values obtained for finite nuclei and symmetric nuclear matter.

Proposed method to measure neutron-neutron contact via photonuclear spin correlations.

Established a theoretical bridge between Levinger constant and nuclear contact.

Abstract

The nuclear neutron-proton contact is introduced, generalizing Tan's work, and evaluated from medium energy nuclear photodisintegration experiments. To this end we reformulate the quasi-deuteron model of nuclear photodisintegration and establish the bridge between the Levinger constant and the contact. Using experimental evaluations of Levinger's constant we extract the value of the neutron-proton contact in finite nuclei and in symmetric nuclear matter. Assuming isospin symmetry we propose to evaluate the neutron-neutron contact through measurement of photonuclear spin correlated neutron-proton pairs.