\midheading{Lepton pair production through photonic initial states, process 310}
\label{subsec:gg2lep}

This process is calculable at leading order LO.
This process represents the production of a lepton pair through an electroweak
process involving two photons in the initial state, $\gamma\gamma \to e^- e^+$.
Since the reaction has initial
photons, it is important to have an accurate parton distribution function for
the photon in the proton, e.g. LUXqed17\_plus\_PDF4LHC15\_nnlo\_30.