The CMS muon system

During the first phase of operation of the LHC, with luminosities of the order of L=10/sup 33/ cm/sup -2/ s/sup -1/, a large production of bb pairs will allow the measurement of CP violation effects and other studies in B-physics. Identification and measurement of muons play an important role in these studies. This will be achieved in CMS with several technologies: in the barrel part, drift tube chambers (DT) can be used, whereas in the endcaps, cathode strip chambers (CSC) are better suited. A third type of detector, resistive plate chambers (RPC) will also be present in both, barrel and endcaps, providing a redundant and complementary trigger. A description of the three detectors, their main features and performance is presented. (12 refs).