Speaker
Simone Pigazzini
(Universita & INFN, Milano-Bicocca (IT). On behalf of the CMS collaboration)
Description
The electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid (CMS) Experiment is made of about 75000 scintillating lead tungstate crystals arranged in a barrel and two endcaps. The single-channel time resolution of ECAL measured at beam tests and for high energy showers from LHC Run I is better than 100 ps.
For the high luminosity phase of the LHC (HL-LHC) we expect an average of 140 to 200 concurrent interactions per bunch crossing (pile-up). This poses a major challenge to the event reconstruction. Studies indicate that very precise timing information, at the level of a few 10 ps, could be exploited for pileup mitigation and for the correct assignment of physics objects to their proper vertices. We will discuss some case studies of the usage of precision timing for HL-LHC. The crystal matrix of the CMS ECAL barrel will be used in the HL-LHC upgrade of the CMS detector. We present results on our R&D program to explore the ultimate timing performance of a PbWO-based crystal calorimeter.
Simulation studies on the timing properties of PbWO crystals, as well as the impact of the photosensors and the readout electronics on the timing performance, will be presented. Test beam studies on the timing performance of PbWO crystals with various photosensors and readout electronics will be shown.
Primary author
Simone Pigazzini
(Universita & INFN, Milano-Bicocca (IT). On behalf of the CMS collaboration)
