W and Z boson production in p–Pb collisions at \(\sqrt{s_{\rm NN}}=5.02\) TeV

Abstract

The W and Z boson production was measured via the muonic decay channel in proton-lead collisions at \(\sqrt{s_{\rm NN}}=5.02\) TeV at the Large Hadron Collider with the ALICE detector. The measurement covers backward \(-4.46 < y_{\rm cms} < 2.96\) and forward \(2.03 < y_{\rm cms} < 3.53\) rapidity regions, corresponding to Pb-going and p-going directions, respectively. The Z-boson production cross section, with dimuon invariant mass of \(60 < m_{\mu\mu}< 120\) GeV/\).^2\) and muon transverse momentum \(p^{\mu}_{\rm T}\) larger than 20 GeV/\).\). is measured. The production cross section and charge asymmetry of muons from W-boson decays with \(p^{\mu}_{\rm T} > 10\) GeV/\).\) are determined. The results are compared to theoretical calculations both with and without including the nuclear modification of the parton distribution functions. The W-boson production is also studied as a function of the collision centrality: the cross section of muons from W-boson decays is found to scale with the average number of binary nucleon-nucleon collisions within uncertainties.