Measurement of W-boson production in p–Pb collisions at = 5.02 TeV with ALICE at the LHC

In hadronic collisions, electroweak bosons are produced in initial hard scattering processes and they are not affected by the strong interaction. In proton–proton collisions, they have been suggested as standard candles for luminosity monitoring and their measurement can improve the evaluation of detector performances. In nucleus-nucleus and proton–nucleus collisions, W-bosons allow one to check at first order the validity of binary collision scaling, while small deviations allow to study the nuclear modifications of parton distribution functions. The W-boson production in p–Pb collisions at √ sNN = 5.02 TeV is measured via the contribution of W-boson decays to the inclusive pT -differential muon yield reconstructed with the ALICE muon spectrometer at forward (2.03 < y cms < 3.53) and backward (−4.46 < y cms < −2.96) rapidity. This paper reports the production cross section of muons from W-boson decays for pμT > 10 GeV/c and the yields normalised to the average number of binary nucleon-nucleon collisions as a function of the event activity.