Precision Timing with the CMS MTD Barrel Timing Layer for HL-LHC

Abstract

The Compact Muon Solenoid detector at the CERN LHC is undergoing an extensive Phase II upgrade program to prepare for the challenging conditions of the High-Luminosity LHC. A new timing detector, MTD, will measure minimum ionizing particles with a time resolution of 30-40 ps at a rate of 2.5 Mhit/s per channel at the beginning of the operations. The precision time information from this detector will reduce the effects of the high levels of pileup, bringing new capabilities to the CMS detector. The barrel timing layer will use sensors that are based on LYSO:Ce scintillating crystals coupled to SiPMs with TOFHIR ASICs for the front-end readout. We will present motivations for precision timing at the High-Luminosity LHC and an overview of the MTD barrel design, including ongoing R&D studies targeting enhanced timing performance and radiation tolerance.