Study of a trigger in p-p events for the HMPID detector in the ALICE experiment at LHC

The ALICE-HMPID detector extends the PID capabilities in the central rapidity region of the ALICE central detectors (ITS, TPC, TOF), by identifying charged pions and kaons with momentum 1<p<3GeV/c and protons 1.5<p<5GeV/c. Because of the small geo metrical acceptance of HMPID, an efficient trigger system could enrich the sample of good events for physics. In this work, a simulation study to select events by using the Fast-OR signal of the ALICE Silicon Pixel Detector (SPD) combined with the signal from the ALICE Time-Of-Flight detector will be presented.