Electroweak bosons in heavy ion collisions in CMS

The Compact Muon Solenoid (CMS) is fully equipped to measure leptonic decays of electroweak probes in the high multiplicity environment of nucleus-nucleus collisions. The inclusive and differential Z boson yields in the muon and electron decay channels are presented, together with measurements of the yield of W bosons decaying into a muon and an (anti)neutrino as a function of centrality, and the W charge asymmetry as a function of rapidity. The results confirm the binary scaling hypothesis, and show that possible modifications due to nuclear PDFs with respect to pp collisions, scaled by the number of elementary nucleon-nucleon collisions, are within the statistical and systematic uncertainties of the current measurements.