Timing detectors in the very forward region of IP5: a study on the Physics potentials

The TOTEM-T2 telescope at the LHC detects charged particles produced by the inelastic interactions at very small polar angles (3-10 mrad). It has been used to perform inelastic cross sections and multiplicities measurements, during dedicated LHC fills with a low pile-up probability. The detector performances and the measurement of the charged particle pseudorapidity density, for different categories of inelastic events, will be reported. Tracks reconstruction in the CMS forward region, where T2 is installed, is challenged by a large amount of secondary particles generated by the interaction with the material placed between the IP and T2. Therefore T2 cannot be used at high luminosity, due to the large occupancy and to the impossibility to distinguish multiple vertices. The introduction of a timing detector close to T2 would allow one to reduce the analysis uncertainties at low pile-up and would make possible the association of the correct inelastic vertex reconstructed by CMS or by the TOTEM RP detectors. A study on the Physics potentials of an upgrade programme aiming to provide the timing information in the T2 region will be reported.