Measurement of the forward W boson cross-section in pp collisions at s = 7 $$ \sqrt{s}=7 $$ TeV

Abstract

A measurement of the inclusive W production cross-section using data from pp collisions at a centre-of-mass energy of s = 7 TeV is presented. The analysis is based on an integrated luminosity of about 1.0 fb -1 recorded with the LHCb detector. Results are reported for muons with a transverse momentum greater than 20 GeV/c and pseudorapidity between 2.0 and 4.5. The W + and W -production cross-sections are measured to be W + + = 861.0 2.0 11.2 14.7 pb , W - - = 675.8 1.9 8.8 11.6 pb , where the first uncertainty is statistical, the second is systematic and the third is due to the luminosity determination. Cross-section ratios and differential distributions as functions of the muon pseudorapidity are also presented. The ratio of W + to W -cross-sections in the same fiducial kinematic region is determined to be