The Laser calibration of the Atlas Tile Calorimeter during the LHC run 1

International audienceThis article describes the Laser calibration system of the ATLAS hadronic Tile Calorimeter that has been used during the run 1 of the LHC . First, the stability of the system associated readout electronics is studied. It is found to be stable with variations smaller than 0.6 %. Then, the method developed to compute the calibration constants, to correct for the variations of the gain of the calorimeter photomultipliers, is described. These constants were determined with a statistical uncertainty of 0.3 % and a systematic uncertainty of 0.2 % for the central part of the calorimeter and 0.5 % for the end-caps. Finally, the detection and correction of timing mis-configuration of the Tile Calorimeter using the Laser system are also presented

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

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$^{-1}$.The luminosity determination for the ATLAS detector at the LHC during Run 2 is presented, with pp collisions at a centre-of-mass energy $\sqrt{s}=13$ 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 luminosity 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 $140.1\pm 1.2$ $\hbox {fb}^{-1}$, i.e. an uncertainty of 0.83%. A dedicated sample of low-pileup data recorded in 2017–2018 for precision Standard Model physics measurements is analysed separately, and has an integrated luminosity of $338.1\pm 3.1$ $\hbox {pb}^{-1}$.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$^{-1}$