Thermal Pair Production from Photon-Photon Collision: Breit-Wheeler Process at Finite Temperature

In this paper we examine the pair production through the Breit-Wheeler process $\gamma~\gamma \to e^+ e^-$ in a thermal background. We compute the thermal contribution to the Breit-Wheeler differential cross section within the thermofield dynamics formalism. We evaluate in details the cross section for this process, which possess a surprisingly simple expression valid for any temperature $\beta$, from which we discuss some physically relevant aspects. We also consider the high temperature regime of the cross section in order to have a better understanding about its thermal behavior.