  The LHC offers unique opportunities for studying the properties of hot QCD
matter created in Pb+Pb 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
Pb+Pb event, CMS is fully equipped to measure dimuons in the high multiplicity
environment of Pb+Pb collisions. Such probes are especially relevant 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 Pb+Pb collisions based on the 2010 LHC runs will be reviewed. CMS is
able to measure primary and secondary J/psi, as well as the three Upsilon
states. Quarkonia results at sqrt(s)=2.76 TeV in pp and Pb+Pb will be
presented, including a tantalizing observation of suppression of the Upsilon
excited states. The Z0 boson inclusive and differential measurement as a probe
of the initial state will be described.
