Use of time information in the High Granularity Calorimeter at the CMS experiment

¹ University and INFN of Milano Bicocca, Milano, Italy
² RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
³ CERN, European Organization for Nuclear Research, Meyrin, Switzerland

^* e-mail: aurora.perego@cern.ch

Published online: 7 March 2025

Abstract

The High-Luminosity phase of the Large Hadron Collider (HL-LHC) starting in 2029 poses unprecedented challenges in terms of data acquisition and event reconstruction. Significant upgrades are planned for both detectors and software to tackle these challenges. Among the strategies adopted by the Compact Muon Solenoid (CMS) experiment there is the incorporation of time-related information from sub-detectors, facilitated by advancements in technology and faster electronics.

The forthcoming High Granularity Calorimeter (HGCAL) is set to replace the current electromagnetic and hadronic calorimeters in the Endcaps. Apart from its exceptional spatial resolution, HGCAL will introduce precise time measurements for high-energy deposits, allowing for a comprehensive 5D reconstruction (x, y, z, t, E) of particle showers. The front-end electronics will measure the time of arrival of pulses above a charge threshold, achieving a resolution as fine as 25 ps for high individual energy deposits.

This research highlights the integration of timing information from the High Granularity Calorimeter into event reconstruction and its use in combination with the information coming from the dedicated timing layer, the MIP Timing Detector, heading towards an enhanced global event interpretation in the high pileup environment of the HL-LHC.