Speaker: Rádl Attila (ELTE, Wigner RCP)

Title Precision luminosity measurement at the CMS experiment in Run 2 and prospects for HL-LHC

Date: 12 December 2022, 10:00

Place: Building 2, Media Room, and on Zoom:  https://cern.zoom.us/j/67590004845?pwd=TmhMaVpCOFhQZ3RCRUJwVUVMSFV0dz09



Precision luminosity measurements are an essential ingredient to cross section measurements at the LHC and its high-luminosity upgrade (HL-LHC), needed to determine fundamental parameters of the standard model and to constrain or discover beyond-the-standard-model phenomena. The luminosity measurement of the CMS detector at the LHC, using proton-proton collisions at 13 TeV during the 2015–2018 data-taking period, is reported. The absolute luminosity scale is obtained with beam-separation scans, and several systematic uncertainty sources are studied, including additional contributions from the linearity and stability of the detectors. Meanwhile, the HL-LHC is foreseen to reach an instantaneous luminosity a factor of five to seven times the nominal LHC design value. The resulting, unprecedented requirements for luminosity and background monitoring measurements are presented, tackled by upgraded or new high-precision radiation-hard instrumentation at CMS. The exploitation of the tracker endcap pixel detector, the outer tracker, the hadron forward calorimeter, the barrel muon detectors and the 40 MHz scouting system is discussed together with the concept of a standalone luminosity and beam-induced background monitor using Si-pad sensors.