Separating the Z$^{0}$ from Heavy Quark Background in Relativistic Heavy Ion Collisions

The Compact Muon Solenoid at the Large Hadron Collider (LHC) is scheduled to begin experimental operations in late 2007. At full power, Pb-Pb collisions at LHC will produce quark gluon plasma (QGP), as well as numerous particle jets. In order to determine the energies of these jets, Z$^{0}$ bosons coming out of the plasma on the opposite side of the jet are examined. Direct observation of the Z$^{0}$ particle is impossible because it decays before reaching the detectors. It is possible to measure the decay products of the Z$^{0}$ to reconstruct the particle's energy prior to exiting the QGP. Some of the most useful decay products of the Z$^{0}$ to study are dimuons produced as a particle antiparticle pair. Dimuons are also copiously produced from decays of other particles, most notably, decays of D and B mesons originating from heavy quark pairs. These false Z0s constitute the background for experiments. Using various simulations, the dimuon signals from the Z$^{0}$ decays and the D and B decays have been modeled. Based on the simulated data, a series of limits on accepted values for such physical quantities as opening angle and decay momentum asymmetry have been established to maximize the signal to background ratio for Z$^{0}$ particles in the detector.