The CMS Muon System Upgrade for High Luminosity LHC

To withstand the challenging conditions of increased luminosity and higher pileup expected during the high-luminosity LHC (HL-LHC), the muon spectrometer of the CMS experiment will undergo specific upgrades targeting both electronics and detectors. The goal is to cope with the new challenging data-taking conditions of HL-LHC and to improve the present tracking and triggering capabilities. The electronics upgrades will target the existing Drift Tubes (DT) in the Muon central barrel section, Cathode Strip Chambers (CSC) in the Muon end-cap sections, and Resistive Plate Chambers (RPC) in the Muon barrel and end-cap sections. New detector stations will be deployed in the Muon end-caps where the background rate is expected to be higher. The detector upgrades are based on triple gas electron multiplier (GEM) and improved RPC (iRPC) technologies, featuring improved time and spatial resolutions, and enhanced rate capability. This document presents an overview of the Muon System upgrades, ongoing activities, and plans.