2025/03/13 by Kim, Sang-Ho · 1 citation
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2503.09995
The photoproduction of J/ψ meson off the nucleon is investigated within a dynamical model approach based on a Hamiltonian which describes the reaction mechanisms of the Pomeron exchange, meson exchange, and direct J/ψ radiation terms.To shed light on the low-energy mechanism, we scrutinize the role of light-meson [π0(135), η(548), η'(958), f1(1285)] and charmonium-meson [ηc(1S), χc0(1P), χc1(1P), ηc(2S), χc1(3872)] exchanges in the t-channel diagram. The values of the coupling constants are mostly determined by the radiative decays of the J/ψ meson or the relevant charmonium mesons. The final J/ψ-N interaction is required by the unitarity condition and is described by the gluon-exchange and direct J/ψN coupling terms. The parameters of the Hamiltonian are determined by the latest GlueX and J/ψ-007 experiments at the Jefferson Laboratory (JLab). We find that η(548) and η'(958) light mesons give the most significant contribution to γp → J/ψp among the meson-exchange terms.Meanwhile, the effect of charmonium mesons turns out to be small compared to that of light mesons.It turns out that the contribution of the FSI term is about 1 - 2 orders of magnitude smaller than that of the Born term and is significant near the threshold when the Yukawa form is used as for the charmonium-nucleon potential. The resulting total and t-dependent differential cross sections provide good agreement with the JLab data. The angle-dependent data with high precision near the very threshold (Eγ\leqslant 8.9 GeV) are strongly desired to pin down the role of the FSI term more properly.