J/$\psi \to mu^(+)mu^(-)$ Reconstruction in CMS

In this note the J/Psi -> mu+mu- reconstruction performance in CMS is studied in detail by using Bs -> J/Psi + Phi -> mumuKK events. The reconstruction efficiencies of J/Psi mesons and their decay muons are obtained as a function of the transverse momentum pT and the pseudo-rapidity eta. We also study the muon trigger efficiency for this channel with the planned Level-1 trigger and High Level Trigger selection criteria. It was observed that the muon reconstruction efficiency decreases when the two decay muons have a small or large 3D angular separation, which further affects the overall J/Psi reconstruction efficiency. Finally, we obtain upper limits on the efficiency and mass resolution for J/Psi offline reconstruction in CMS using dedicated samples with single J/Psi particles.