Estimating the production of dark photons with η decay in Ultra-peripheral Collisions

We propose that the signal of dark photons can be found in the decay channel of η, and that a certain number of events of dark photon leptonic decay can be observed in the double-photon collision process of heavy-ion ultra-peripheral collisions (UPC). We estimate the total cross-section for producing dark photons in ultra-peripheral $PbPb$ collisions at existing and planned future hadron colliders, as well as the number of signal events. Our results support the search for dark photon signals in ultra-peripheral $PbPb$ collisions. We consider the recent signals of η decays produced in LHC $pp$ collisions and estimate the number of dark photon events from the same number of η decays from CMS. Based on CMS results, we estimate that there will be at least 1000 signal events of dark photons observed for the mass mA^ less than 500 MeV. In this study, we propose a method using η meson decay to search for signs of dark photons at heavy-ion colliders, such as LHC and RHIC.