# Coarse graining of NN inelastic interactions up to 3 GeV:Repulsive vs Structural core

## TL;DR

This paper compares two models of NN interactions up to 3 GeV, one with a repulsive core and one with a structural core, analyzing their energy dependence and implications for nuclear structure.

## Contribution

It introduces a coarse grained approach to NN interactions up to 3 GeV, contrasting repulsive and structural core scenarios and their energy-dependent behaviors.

## Key findings

- Repulsive core exhibits strong energy dependence.
- Structural core shows adiabatic energy dependence.
- Implications for nuclear structure calculations are discussed.

## Abstract

The repulsive short distance core is one of the main paradigms of nuclear physics which even seems confirmed by QCD lattice calculations. On the other hand nuclear potentials at short distances are motivated by high energy behavior where inelasticities play an important role. We analyze NN interactions up to 3 GeV in terms of simple coarse grained complex and energy dependent interactions. We discuss two possible and conflicting scenarios which share the common feature of a vanishing wave function at the core location in the particular case of S- waves. We find that the optical potential with a repulsive core exhibits a strong energy dependence whereas the optical potential with the structural core is characterized by a rather adiabatic energy dependence which allows to treat inelasticity perturbatively. We discuss the possible implications for nuclear structure calculations of both alternatives.