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

The production of ${\eta }^{\mathrm{\prime }}$ mesons in the reactions $pp\to pp{\eta }^{\mathrm{\prime }}$ 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 ${\eta }^{\mathrm{\prime }}$ Dalitz decay ${\eta }^{\mathrm{\prime }}\to \gamma {\gamma }^{\ast }\to \gamma e^{+}{e}^{-}$ is also calculated and numerical results are presented for intermediate energy and kinematics of possible experiments with HADES, CLAS and KEK-PS.