Development of data certification for CMS gas electron multiplier detector using cosmic ray muons and proton-proton collisions

After the Phase-2 high-luminosity upgrade to the Large Hadron Collider (LHC), the collision rate and therefore the background rate will significantly increase, particularly in the high-$\eta$ region. To improve both the tracking and triggering of muons, the Compact Muon Solenoid (CMS) Collaboration plans to install triple-layer Gas Electron Multiplier (GEM) detectors in the CMS muon endcaps. As the first part of this upgrade, the installation of 144 triple-GEM GE1/1 chambers in the end caps of the CMS muon system in late 2020. The chambers have passed rigorous quality-control checks and are currently being commissioned. Initial data has been recorded by the GE1/1 detector using cosmic ray muons as well as proton-proton collision data. Dedicated data collection runs with and without the CMS 3.8 T magnetic field were performed. Certification procedures for this new GEM system have been developed and are being integrated with the existing procedures from the other CMS muon subsystems.