Speaker
Description
The W boson is a short lived particle which does not interact strongly. Thus its production rate measured in lepton decay channels can be compared between lead-lead and proton-proton collisions as a direct test of both binary collision scaling and the possible modification of parton distribution functions (nPDF) due to nuclear effects. The ATLAS detector has recorded 0.49 nb-1 of lead-lead collision data at the center-of-mass energy of 5.02 TeV, where W boson production yield is increased by a factor of eight relative to the available Run 1 data at 2.76 TeV. This study presents W+ and W- boson production yields measured differentially in lepton pseudorapidity and as a function of centrality, as well as the pseudorapidity dependence of the lepton charge asymmetry.