An in-medium full-folding model approach to quasielastic (p,n) charge-exchange reactions

TL;DR

This paper develops a microscopic coupled-channel model for quasielastic (p,n) charge-exchange reactions, emphasizing spin-isospin interactions and off-shell effects, to predict differential cross sections with reasonable accuracy at energies above 100 MeV.

Contribution

It introduces a non-local, off-shell full-folding optical model extension for charge-exchange reactions, focusing on spin-isospin structure and medium effects.

Findings

Reasonable agreement with $^{14}$C(p,n) data above 100 MeV

Model's accuracy decreases for heavier targets

Discussion of potential corrections to improve predictions

Abstract

A microscopic description of the quasielastic (p,n) charge-exchange reaction (here, charge-exchange scattering between analogue states) is presented and discussed. Emphasis is focused on the spin-isospin structure of the projectile-target coupling. The model is a coupled-channel extension of the full-folding optical model approach (OMP) developed for nucleon elastic scattering, where emphasis is placed on retaining the genuine off-shell behavior of realistic effective interactions in the nuclear medium. The resulting non-local optical potentials are applied to the calculation of (p,n) differential cross sections, with particular emphasis on small-angle Fermi ($\Delta S=0$) cross-sections to isobaric analog states. These parameter-free results provide a reasonable description of the $^{14}$C(p,n)-data at proton energies above $\sim$100 MeV, but deteriorate for heavier targets. These shortcomings are analyzed and possible ways to correct them are discussed.