Pion Exchange Interaction in Bonn Potential and Relativistic and Non-relativistic Framework in Nuclear Matter

TL;DR

This paper discusses the role of pion exchange in the Bonn nucleon-nucleon potential and explores its implications in both relativistic and non-relativistic models of nuclear matter, highlighting recent high-precision potentials and ab initio methods.

Contribution

It introduces recent high-precision charge-dependent Bonn potentials with pseudovector coupling and analyzes their impact in nuclear matter within different theoretical frameworks.

Findings

Pion exchange significantly influences the tensor component of the NN potential.

Recent Bonn potentials improve the understanding of nuclear matter properties.

Relativistic ab initio methods effectively address short-range repulsion and tensor forces.

Abstract

As the residual interaction of quantum chromodynamics in low-energy region, the nucleon-nucleon (NN) potential can only be exactly described by the model picture now. In the Bonn potential, one of the most well-known NN interaction models, the nucleons interact with each other through exchanging the pion and several heavier mesons, where the pion plays an essential role. It provides a partial contribution of tensor force in the intermediate-range region and the main component in the long-range region in NN potential. However, it is very difficult to be treated in the nuclear many-body system due to its pseudovector or pseudoscalar property. Recently, three high-precision charge-dependent Bonn potentials were proposed with pseudovector coupling types and different pion-nucleon coupling strengths and applied them to study the properties of nuclear matter and neutron stars in the non-relativistic and relativistic frameworks. Furthermore, to properly deal with the strong short-range repulsion and tensor force of the NN potential, some new relativistic {\it ab initio} methods have also been developed in the past decade to discuss the role of pion and relativistic effects in nuclear matter.