Orateur
Description
The High-Luminosity phase of the Large Hadron Collider (HL-LHC), is expected to start in 2030. It will bring around a 2.5-to-4-fold increase in instantaneous luminosity, raising pileup up to 200 collisions per bunch crossing and increasing radiation damage to the detectors. To cope with this pileup and replace aging components, several subdetectors of the major experiments must be upgraded ahead of the HL phase.
In CMS, the endcap calorimeters will be replaced by the High-Granularity Calorimeter (HGCAL), a 47-layer silicon and scintillator detector combining electromagnetic and hadronic sections in a single structure. It will provide precise position, time and energy measurements, targeting a time resolution under 30 ps at cluster level to enable accurate event reconstruction despite the increased pileup.
Several testbeam campaigns have been carried out at CERN over the past years to prepare HGCAL's commissioning. We present a summary of the timing performance analysis from the 2025-2026 campaign: after a broad introduction to HGCAL and the testbeams, we will focus on the timing studies and their results, including the use of Micro-Channel Plate detectors as time reference.