HGCAL Electromagnetic Calorimeter Performance

Abstract

The High-Granularity Calorimeter (HGCAL) is an important component of the High Luminosity LHC (HL-LHC) upgrade for the CMS experiment. With electromagnetic (CE-E) and hadronic (CE-H) sections, these calorimeters are designed to withstand and operate in high radiation environments. We primarily studied the CE-E region at the TeV and GeV regimes. Motivations for this research include identifying software inconsistencies and calibration issues, as well as overall design limitations; it supplements efforts in shower leakage correction for the detector as a whole by investigating electron energy reconstruction. Using electron and positron particle gun simulations, generated with CMSSW (CMS Offline Software), our study tries to answer questions related to detector performance at specific regions of the HGCAL, focusing on pseudorapidity (η) ranges of 1.5 to 1.6 and 2.9 to 3.0 at two different energy values. We quantified the η dependence of electrons and found that not only are electron reconstruction energy resolutions energy dependent, they are also η dependent. We assert that this is an underlying detector geometry issue that may be addressed by future updates to HGCAL detector geometry, as well as more advanced reconstruction techniques. Hence, our next step will include conducting the same study with a sample simulated with updated detector geometries.