Theoretical study on pp --> p n pi+ reaction at medium energies

TL;DR

This paper extends a resonance model to analyze the $pp o p n \pi^+$ reaction at medium energies, providing detailed predictions of differential cross sections and identifying contributions from various nucleon resonances.

Contribution

The work introduces an extended resonance model that accurately reproduces total cross sections and offers detailed differential predictions for the reaction at specific energies.

Findings

Resonance contributions from $N^*$ and $\Delta^{*}$ up to 2 GeV are quantified.

The model reproduces observed total cross sections well.

Predictions for differential cross sections at $T_p=2.88$ GeV are provided.

Abstract

The $pp\to p n \pi^+$ reaction is a channel with the largest total cross section for pp collision in COSY/CSR energy region. In this work, we investigate individual contributions from various $N^*$ and $\Delta^{*}$ resonances with mass up to about 2 GeV for the $pp\to p n \pi^+$ reaction. We extend a resonance model, which can reproduce the observed total cross section quite well, to give theoretical predictions of various differential cross sections for the present reaction at $T_p=2.88$ GeV. It could serve as a reference for identifying new physics in the future experiments at HIRFL-CSR.