CMS Level-1 Trigger for b-physics studies

The CMS Level-1 Trigger system is described with an emphasis on algorithms useful for b-physics studies. Special algorithm is designed for electrons from b-quark decays. It takes advantage of fine granularity crystal electromagnetic calorimeter. One can achieve 10 GeV and 5 GeV thresholds for single and double electron trigger respectively. The muon trigger combines fast dedicated detectors ( RPC) with precise muon chambers ( Drift Tubes, CSC). They provide a sharp pt cut which can be set at ~8-10 GeV for single muon trigger. The two muon trigger pt cut is limited only by the energy loss in absorber and equal to ~4 GeV in the barrel, decreasing down to ~2 GeV in the endcaps.