Implication of CMS data on photon PDFs

Understand

As part of a recent analysis of exclusive two-photon production of W+ W- pairs at the LHC, the CMS experiment used di-lepton data to obtain an "effective" photon-photon luminosity.

• We show how the CMS analysis on their 8 TeV data, along with some assumptions about the likelihood for events in which the proton breaks up to pass the selection criteria, can be used to significantly constrain the photon parton distribution functions, such as those from the CTEQ, MRST, and NNPDF collaborations.
• We compare the data with predictions using these photon distributions, as well as the new LUXqed photon distribution.
• We study the impact of including these data on the NNPDF2.3QED, NNPDF3.0QED and CT14QEDinc fits.