Abstract We investigate the e^+ e^- J/ e + e - → η J / ψ cross section by employing a model that combines relativistic Breit–Wigner amplitudes with a unitarized coupled-channel approach to account for resonant and non-resonant contributions, respectively. By performing a global fit to the BESIII experimental data, we determine the essential free parameters of the transition amplitudes. Furthermore, we analyze the role of a dynamically generated DD^* D D ¯ ∗ pole near 3. 88 GeV and demonstrate its critical contribution to shaping the observed cross-section line shape.
Sara Rahmani (Thu,) studied this question.