Performance of the muon trigger with a realistic simulation

In this note we study the performance of the level 0 muon trigger algorithm with a simulation very close to the hardware implementation. The description of the detector is based on the version 239 of the database, corresponding to a LHCb- classic set up. The Monte-Carlo data samples take into account inelastic non diffractive, inelastic diffractive and elastic proton-proton interactions as well as pile up events. The performance is studied in various background conditions in the muon stations, including the one induced by the LHC beams. The b®mX efficiency is % and the B0®J/y(m+m-)Ks efficiency is %, for a level zero muon trigger output rate of 200 kHz after the pile up veto. The first reported uncertainty is only statistical. The second one is the systematic uncertainty, reflecting our imperfect knowledge of the background conditions. The performance is also studied varying the muon chamber digitization parameters and do not show strong dependence on these parameters, in particular on the cluster size and the station efficiency.