Abstract:
The calibration for the CMS luminosity measurement for the 2018 LHC run is described. The principal calibration is derived from the analysis of the van der Meer scan program in CMS taken in LHC fill 6868 on June 30th–July 1st, 2018. Additionally, the performance and stability of the CMS luminometers is evaluated using emittance scans taken throughout the course of the year. The systematic uncertainty on the absolute calibration from the van der Meer scan is measured as 2.1%. The dominant systematic uncertainties in the van der Meer calibration are those arising from the x-y correlations of the beam shape and the scan to scan variations.
