Constraints on the kinetic mixing parameter ${\epsilon }^2$ for the light dark photons from dilepton production in heavy-ion collisions in the few-GeV energy range

Ida Schmidt, Elena Bratkovskaya, Malgorzata Gumberidze +1

The vector $U$-bosons, or so called 'dark photons', are one of the possible candidates for the dark matter mediators. They are supposed to interact with the standard matter via a '…