Timing information and pileup rejection for the High Granularity Calorimeter

The Large Hadron Collider (LHC) at CERN is the world’s largest and most energetic hadron collider. The first run of the LHC (March 2010 - December 2012) has led to several measurements and discoveries, amongst which the Higgs boson candidate. In order to further increase its discovery potential beyond 2020 a leap in luminosity, by a factor of 10, is needed. It is what we call High Luminosity LHC (HL-LHC). Increase the total number of collision would provide more accurate measurements of new particles and enable observation of rare processes that occur below the current sensitivity level. The increase in luminosity will be achieved at the cost of an increase in pileup, i.e. the number of simultaneous collisions. Not only the LHC machine will be upgraded but also the detectors, namely CMS . To cope with this high pileup environment and reconstruct physics objects such as electrons, photons, jets and taus, High Granularity Calorimeter is being proposed as a substitute of the current endcap calorimeters of CMS. The high segmentation are expected to bring benefits in taming the pileup contamination of signal events. During my project I have studied how to use additional timing information from energetic hits provide by front-end electronics may be used in order to improve vertex discrimination.