Dimuon results in PbPb and pp collisions in CMS

The unprecedented center-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 in the high-level trigger, CMS is fully equipped to study dimuon production in the high multiplicity environment of nucleus-nucleus collisions. Such probes are especially relevant for these studies since they are produced at early times and propagate through the medium, mapping its evolution. The capabilities of the CMS experiment to study dimuon production in $pp$ and PbPb collisions based on LHC runs in 2010 and 2011 will be reviewed. In particular, CMS is able to measure primary and secondary J/$\psi$s, but also the first 3 $\Upsilon$ states, differentially in $p_T$ and rapidity. In heavy ions, the observation of quarkonia at $\sqrt{s_{NN}} = 2.76~\mathrm{TeV}$ will be presented, and the Z boson inclusive and differential measurement as probe of the initial state will be detailed.