QCD analysis of CMS W + charm measurements at LHC with s = 7TeV and implications for the strange PDF
Abstract
We calculate cross-sections and cross-section ratios of a charm quark production in association with a W gauge boson at next-to-leading order QCD using MadGraph and CT10NNLO, CT14NNLO, and MSTW2008NNLO PDFs. We compare the results with measurements from the CMS detector at the LHC at a center-of-mass energy of 7TeV. Moreover, we calculate absolute and normalized differential cross-sections as well as differential cross-section ratios as a function of the lepton pseudorapidity from the W boson decay. The correlation between the CT14NNLO PDFs and predictions for W+ charm data are studied as well. Furthermore, by employing the error PDF updating method proposed by the CTEQ-TEA group, we update CT14NNLO PDFs, and analyze the impact of CMS 7TeV W+ charm production data to the original CT14NNLO PDFs. By comparison of the g(x,Q), s(x,Q), u(x,Q), d(x,Q), u(x,Q), and d(x,Q) PDFs at Q=1.3 GeV and Q = 100 GeV for the CT14NNLO and CT14NNLO+Wc, we see that the error band of the s(x,Q) PDF is reduced in the region x<0.4, and the error band of g(x,Q) PDF is also slightly reduced in the region 0.01 < x < 0.1.