The Photon Content of the Proton

Understand

The photon PDF of the proton is needed for precision comparisons of LHC cross sections with theoretical predictions.

• In a recent paper, we showed how the photon PDF could be determined in terms of the electromagnetic proton structure functions $F_2$ and $F_L$ measured in electron-proton scattering experiments, and gave an explicit formula for the PDF including all terms up to next-to-leading order.
• In this paper we give details of the derivation.
• We obtain the photon PDF using the factorisation theorem and applying it to suitable BSM hard scattering processes.