SMuK 2023 – wissenschaftliches Programm

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T: Fachverband Teilchenphysik

T 43: Electronics, DAQ, Exp. Methods

T 43.4: Vortrag

Dienstag, 21. März 2023, 17:45–18:00, POT/0106

Absolute luminosity calibration through van der Meer scans in ATLAS — •Cédrine Hügli for the ATLAS collaboration — DESY Zeuthen

Luminosity is a very important quantity for many physics analyses. Its precise knowledge is required for example in cross section measurements. In ATLAS, luminosity is measured by several detectors: the main luminometer is LUCID, located in the forward region and based on Cherenkov radiation. All luminosity detectors need to be absolutely calibrated through so-called van der Meer scans. These are scans where the two beams are scanned through each other, first in the horizontal and then in the vertical plane. In this work, the preliminary analysis of the run 3 13.6 TeV van der Meer scan from 2022 is presented. The analysis precisely measures the part of the inelastic proton-proton interaction cross section visible in the luminosity detectors, which is the absolute luminosity calibration constant. Its value is obtained by fitting the scan curves. During the van der Meer scan analysis several effects need to be corrected to get a precise calibration constant, for example the impact of the electromagnetic interaction of the beams on their separation. The obtained absolute calibration of luminosity is then transferred to physics conditions and used in the early run 3 ATLAS measurements.