TY - JOUR

T1 - Performance of the ATLAS track reconstruction algorithms in dense environments in LHC Run 2

AU - Barton, Adam Edward

AU - Beattie, Michael

AU - Bertram, Iain Alexander

AU - Borissov, Guennadi

AU - Bouhova-Thacker, Evelina Vassileva

AU - Dearnaley, William

AU - Fox, Harald

AU - Grimm, Kathryn Ann Tschann

AU - Henderson, Robert Charles William

AU - Hughes, Gareth

AU - Jones, Roger William Lewis

AU - Kartvelishvili, Vakhtang

AU - Long, Robin Eamonn

AU - Love, Peter Allan

AU - Muenstermann, Daniel Matthias Alfred

AU - Parker, Adam Jackson

AU - Skinner, Malcolm

AU - Smizanska, Maria

AU - Walder, James William

AU - Wharton, Andy

AU - Whitmore, Ben

AU - The ATLAS collaboration

PY - 2017/10/1

Y1 - 2017/10/1

N2 - With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb −1−1 of data collected by the ATLAS experiment and simulation of proton–proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 TeVTeV . The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600 GeVGeV is quantified using a novel, data-driven, method. The method uses the energy loss, dE/dx dE/dx , to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is 0.061±0.006 (stat.)±0.014 (syst.)0.061±0.006 (stat.)±0.014 (syst.) and 0.093±0.017 (stat.)±0.021 (syst.)0.093±0.017 (stat.)±0.021 (syst.) for jet transverse momenta of 200–400 GeVGeV and 1400–1600 GeVGeV , respectively.

AB - With the increase in energy of the Large Hadron Collider to a centre-of-mass energy of 13 TeV for Run 2, events with dense environments, such as in the cores of high-energy jets, became a focus for new physics searches as well as measurements of the Standard Model. These environments are characterized by charged-particle separations of the order of the tracking detectors sensor granularity. Basic track quantities are compared between 3.2 fb −1−1 of data collected by the ATLAS experiment and simulation of proton–proton collisions producing high-transverse-momentum jets at a centre-of-mass energy of 13 TeVTeV . The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The track reconstruction efficiency in the cores of jets with transverse momenta between 200 and 1600 GeVGeV is quantified using a novel, data-driven, method. The method uses the energy loss, dE/dx dE/dx , to identify pixel clusters originating from two charged particles. Of the charged particles creating these clusters, the measured fraction that fail to be reconstructed is 0.061±0.006 (stat.)±0.014 (syst.)0.061±0.006 (stat.)±0.014 (syst.) and 0.093±0.017 (stat.)±0.021 (syst.)0.093±0.017 (stat.)±0.021 (syst.) for jet transverse momenta of 200–400 GeVGeV and 1400–1600 GeVGeV , respectively.

U2 - 10.1140/epjc/s10052-017-5225-7

DO - 10.1140/epjc/s10052-017-5225-7

M3 - Journal article

VL - 77

JO - European Physical Journal C: Particles and Fields

JF - European Physical Journal C: Particles and Fields

SN - 1434-6044

IS - 10

M1 - 673

ER -