VHMPID detector for the ALICE upgrade at the LHC: Simulation results on mirror segmentation

The Very High Momentum Charged Particle Identification (VHMPID) detector represents a possible upgrade for the ALICE experimental apparatus. It has been conceived to extend protons identification on a track-by-track basis up to p=30 GeV/c. The VHMPID is a ring imaging Cherenkov with C4F10 gaseous radiator coupled to CsI-based photon detector. The focusing properties of a spherical mirror are exploited to focus Cherenkov photons on the photon detector. Mirror segmentation is a critical parameter for the ring pattern recognition performance and for the capability to identify tracks close in phase space. This feature is crucial for the contribution of VHMPID to the ALICE jets physics program. We will present the results of simulation studies that have been carried out in order to optimize the mirror segmentation.