eta-prime Meson Production in Nucleon-Nucleon Collisions Near The Threshold

TL;DR

This paper models eta-prime meson production in nucleon-nucleon collisions near threshold energies using a covariant meson-nucleon theory, fitting data and predicting outcomes for various channels and decay processes relevant to experiments.

Contribution

It introduces a covariant effective meson-nucleon approach including specific resonances to describe eta-prime production and predicts di-electron yields from eta-prime Dalitz decay.

Findings

Successful description of cross sections and angular distributions in pp channel

Predictions for pn channel production cross sections

Numerical results for eta' Dalitz decay relevant to experiments

Abstract

The production of $\eta'$ mesons in the reactions $pp\to pp\eta'$ and $pn\to pn\eta' $ at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. The description of cross section and angular distributions of the available data in this kinematical region in the $pp$ channel is accomplished by including meson currents and nucleon currents with the resonances $S_{11}(1650)$, $P_{11}(1710)$ and $P_{13}(1720)$. Predictions for the $pn$ channel are given. The di-electron production from subsequent $\eta'$ Dalitz decay $\eta' \to \gamma \gamma^* \to\gamma e^+e^-$ is also calculated and numerical results are presented for intermediate energy and kinematics of possible experiments with HADES, CLAS and KEK-PS.