Extent of sensitivity of single photon production to parton distribution functions

We have studied the production of single isolated prompt photons in high-energy proton proton collisions at the RHIC (root s = 200 GeV) and the LHC (root s = 7 TeV) energies within the framework of perturbative QCD upto next-to-leading order of strong coupling (alpha(s)). We have used five different parametrizations of parton distribution function (PDF) starting from the old CTEQ4M to the new CT10 distributions and compared our results with the recent single-prompt photon data from the PHENIX and the CMS Collaborations. The prompt photon cross-section is found to be described equally well by all the PDFs within the experimental errors at the RHIC and the LHC energies. The deviation in the single-prompt photon yield for different PDF sets is within +/- 20% when compared to CTEQ4M, indicating the upper bound of uncertainty in determining the gluon density. The diphoton measurement could be a potential candidate to constrain the gluon distribution inside the proton.