Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC

TL;DR

This paper details the methods and results of luminosity measurement in proton-proton collisions at 13 TeV using the ATLAS detector, achieving an uncertainty below 1% for the full Run 2 dataset.

Contribution

It presents a comprehensive approach combining van der Meer scans and detector measurements to determine luminosity with high precision during Run 2.

Findings

Integrated luminosity for Run 2 is 140.1 fb$^{-1}$ with 0.83% uncertainty.

Dedicated low-pileup data sample has 338.1 pb$^{-1}$ with 0.92% uncertainty.

Total uncertainties in luminosity measurements range from 0.9% to 1.1%.

Abstract

The luminosity determination for the ATLAS detector at the LHC during Run 2 is presented, with $pp$ collisions at $\sqrt{s}=13$ TeV. The absolute luminosity scale is determined using van der Meer beam separation scans during dedicated running periods in each year, and extrapolated to the physics data-taking regime using complementary measurements from several luminosity-sensitive detectors. The total uncertainties in the integrated luminosities for each individual year of data-taking range from 0.9% to 1.1%, and are partially correlated between years. After standard data-quality selections, the full Run 2 $pp$ data sample corresponds to an integrated luminosity of $140.1\pm 1.2$ fb$^{-1}$, i.e. an uncertainty of 0.83%. A dedicated sample of low-pileup data recorded in 2017-18 for precision Standard Model physics measurements is analysed separately, and has an integrated luminosity of $338.1\pm 3.1$ pb$^{-1}$.