CMS RPC background studies in LHC Run 2 and Run 3

Abstract

The Compact Muon Solenoid (CMS) is a general purpose experiment to explore the physics of the TeV scale in proton–proton collisions provided by the CERN LHC. Muons constitute an important signature of new physics and their detection, triggering, reconstruction and identification is guaranteed by various sub-detectors using different detection systems. During Run 2 and Run 3, the higher instantaneous luminosity leads to a substantial background in the muon system. The analysis is based on data collected in pp collisions at 13.6 TeV (Run 2) and 13.6 TeV (Run 3) in 2018 and 2023–2024, respectively, with instantaneous luminosities up to 2.2 × 1034 cm-2 s-1. A thorough understanding of background rates provides the base for the upgrade of the muon detectors for the High-Luminosity LHC, where the instantaneous luminosity will reach 5–7.5 × 1034 cm-2 s-1, resulting in 140–200 simultaneous proton–proton collisions, i.e. collisions occurring within one single bunch time window. © 2025 Elsevier B.V., All rights reserved.