Role of the low-lying nucleon resonances in the $p\bar{p} \to ψη$ reaction

Abstract

Within the effective Lagrangian approach, we study the $p\bar{p} \rightarrow ψη$ [$ψ\equivψ(3686)$, $J/ψ$] reaction at the low energy where the contributions from nucleon pole and low-lying nucleon resonances, $N(1520)$, $N(1535)$ and $N(1650)$ are considered. All the model parameters are determined with the help of current experimental data on the decay of $ψ\to p \bar{p} η$. Within the model parameters, the total and differential cross sections of the $p\bar{p} \rightarrow ψη$ reaction are predicted. We show that the relative phases between different amplitudes of different nucleon resonance will change significantly the angular distributions of the $\bar{p} p \to ψη$ reaction. Therefore, we conclude that these reactions are suitable to study experimentally the properties of the low-lying nucleon resonance and the reaction mechanisms. We hope that these theoretical calculations can be tested by future experiments.