  Events with isolated leptons and missing energy in the final state are known
to be signatures of new physics phenomena at high energy collider physics
facilities. Standard model (SM) sources of isolated trilepton final states
include gauge boson pair production such as WZ and W gamma^{*}, and t-bar t
production. Symbol gamma^* represents a virtual photon. Our new contribution is
the demonstration that bottom and charm meson decays, b to l X and c to l X$,
produce isolated lepton (l) events that can overwhelm the effects of other
processes. We compute contributions from a wide range of SM heavy flavor
processes. In all these cases, one or more of the final observed isolated
leptons comes from a heavy flavor decay. We propose new cuts to control the
heavy flavor backgrounds in the specific case of chargino plus neutralino pair
production in supersymmetric models.
