Simulation Studies of the Time Digitizer for the CMS Hadron Calorimeter Upgrade

Abstract

The Large Hadron Collider (LHC) has performed exceptionally well so far, delivering more than 10^15 proton-proton collisions with center-of-mass energy up to 8 TeV. It has already provided the data that enabled the CMS and ATLAS experiments to announce discovery of the Higgs boson, but the LHC is still far from achieving its full potential. The LHC will be upgraded in 2013–2014 in order to provide higher energy collisions at higher luminosities, and the Compact Muon Solenoid (CMS) detector must be upgraded in the coming years to take full advantage of this LHC upgrade. As part of this upgrade to CMS, new electronics have been proposed for readout of the CMS hadron calorimeter, including a time digitizer component known as the Time-to-Digital Converter (TDC) that provides high-resolution time information. This thesis investigates simulations of the upgraded CMS detector in order to gain a better understanding of the TDC functionality in the upgraded CMS configuration. These simulations enable calibration of TDC-based timing information, and they reveal that the timing resolution gained through this calibration makes it possible to reject key backgrounds. The advantages of this background rejection provide strong motivation for the proposed upgrades to the CMS detector.