Compton-like dark photon production in electron–nucleus collisions

Abstract

The Compton-like production of massive dark photons is investigated in ultrarelativistic electron–ion collisions by considering the kinetic mixing between the dark photon and the standard model photon. The quasi-real photons in the heavy ion are described by the equivalent photon approximation, and the model is employed to calculate the integrated cross section and event rates as a function of the dark photon mass, m γ′, and mixing parameter, ɛ. Predictions are shown for electron–ion colliders (EICs) in the mass range 100 ⩽ m γ′ ⩽ 500 MeV. Numerical results are provided within the kinematic coverage of the planned machines: an EIC in China (EicC), a polarized EIC at Jefferson Lab (JLEIC), an EIC/USA (EIC), a large hadron electron collider (LHeC) and a future circular collider (FCC-eA). It complements existing search strategies for dark photons in the considered mass interval.