The unprecedented centre-of-mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions at extreme temperatures and very low parton momentum fractions. With its high precision, large acceptance for tracking and calorimetry, and a trigger scheme that allows analysis of each minimum bias PbPb event, CMS is fully equipped to measure dimuons in the high multiplicity environment of nucleus-nucleus

more »

... s. Such probes are especially relevant for these studies since they are produced at early times and propagate through the medium, mapping its evolution. Inclusive and differential measurements of the Z boson yield will be shown, establishing that no modification is observed with respect to theoretical next-to-leading order pQCD calculations. The validity of the Glauber scaling for perturbative cross sections in nucleus-nucleus collisions at the LHC is confirmed. In addition, the status of the quarkonia measurements (primary and secondary J/\psi, and the 3 Upsilon states) will be reviewed, both in pp and in PbPb collisions.