Measurement of Luminosity in the proton-proton collisions at the CMS Experiment of the Large Hadron Collider

The Pixel Cluster Counting (PCC) luminosity measurement method has emerged as a reliable offline technique for luminosity measurement developed for the CMS experiment. The PCC method is studied for its precision in luminosity measurement using 2017, 2018 and 2022 datasets. The results of these studies demonstrate that the PCC luminosity measurement method is stable and linear. Final systematic uncertainty achieved on luminosity measurement for 2018 and 2022 datasets are 2.2% and 1.4% respectively. Moreover, the clusters and coincidences counting algorithms and their optimization for the Phase II High Luminosity LHC (HL-LHC) luminosity measurement are also developed, using simulated datasets for the proposed Phase II pixel detector. Linearity of the Tracker endcap pixel (TEPX) and Disk 4 Ring 1 luminometers is expected to be within 1% (offline) up to a pileup of 200 and their statistical precision per second is about 0.1% at pileup 200.