Measurement of W boson production in the muon channel in Pb+Pb collisions at sqrt(sNN) =5.02 TeV

The production of $W$ bosons in the muon decay channel in lead-lead collisions at a center- of-mass energy of $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV is studied by the ATLAS experiment. The analysis is based on a data sample of 0.49~$\mathrm{nb}^{−1}$ collected in 2015. The dependence on centrality and muon presudorapidity of the W → μν production yields per minimum-bias event divided by the nuclear thickness function is measured for W+ and W− bosons within a fiducial region defined by the detector acceptance. The measured W → μν yields divided by the nuclear thickness function have no dependence on the number of participants. The lepton charge asymmetry is also measured as a function of the muon absolute pseudorapidity. The results are compared to predictions based on the next-to-next-to-leading order calculations with CT10 parton distribution functions as well as to the next-to-leading order mcfm prediction with the EPPS16 and nCTEQ15 nuclear parton distribution functions.