Impact of CMS measurements on PDFs

Abstract

Recently 2 analyses have been published by the CMS collaboration that study the effect of a specific CMS measurement on PDFs. A review of these studies is given here. The first analysis consists of a double differential inclusive jet cross-section measurement, performed on 4.7 fb−1 of data at √s = 7 TeV. Using the HERAFITTER code, the effect of adding this measurement in the PDF fit procedure together with DIS data from HERA-I is studied. The CMS data is able to significantly reduce the uncertainties on the gluon PDF, especially for gluons with large momenta relative to the proton (x > 0:01). A moderate reduction in the uncertainty of the u and d valence quark PDFs is also observed for x > 0:01. The quark PDFs are more directly probed by gauge boson production. Therefore the second analysis studies the effect of W-boson production measurements on PFDs. This consists of a W-boson charge asymmetry measurement and a study of W-boson production in association with a c-(anti-)quark, both performed on 5.0 fb−1 of data at √s = 7 TeV. A clear reduction in the uncertainty on the u and d valence quark PDFs is seen for x < 0:1. Furthermore the W-boson + c-quark production measurements allow for the determination of an independent s quark PDF, which is not possible on DIS data alone.