Impact of the Photon-Initiated process on Z'-boson searches in di-lepton final states at the LHC

Understand

We discuss the effect of the Photon Initiated (PI) process on the dilepton channel at the LHC.

• Adopting various QED PDF sets, we evaluate the contribution produced by two resolved photons which is not included in the Equivalent Photon Approximation (EPA).
• We compare the PI central value as predicted by the CTEQ, MRST and NNPDF collaborations.
• With the NNPDF2.3QED set of replicas we also estimate the PDF uncertainties on the PI central value.