Improving spatial and PID performance of the high transparency Drift Chamber by using the Cluster Counting and Timing techniques

Abstract The Helium based ultra-low mass and high granularity Drift Chambers are an optimal solution as tracking systems in modern High Energy Physics experiments for the search of extremely rare processes (MEG-II) and for experiments at future high luminosity e + e − colliders (FCC/CEPC). For the search of rare processes in the cLFV sector the tracking resolutions are dominated by multiple scattering contributions and this impose the use of a ultra-light tracking system. For the future collider in addition to a high tracking performances, a great particle identification (PID) capabilities can have a great impact. We present how, in Helium based gas mixtures, by counting and measuring the arrival times of each individual ionization cluster and by using statistical tools it is possible to have a bias free estimate of the impact parameter and a better PID discrimination by using the dN/dx technique instead of the dE/dx.