2017/04/30 by ATLAS Collaboration · 1 citation
Physics and Astronomy · #hep-ex
paper · pdf · doi:10.1140/epjc/s10052-017-5225-7
published as Eur. Phys. J. C 77 (2017) 673 · 44 pages in total, author list starting page 28, 17 figures, 1 table, submitted to EPJC, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/PERF-2015-08/
arxiv created 2017/10/26 · arxiv updated 2017/10/27
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 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 TeV. The impact of charged-particle separations and multiplicities on the track reconstruction performance is discussed. The efficiency in the cores of jets with transverse momenta between 200 GeV and 1600 GeV is quantified using a novel, data-driven, method. The method uses the energy loss, 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 \textrm(stat.) ± 0.014 \textrm(syst.) and 0.093 ± 0.017 \textrm(stat.)± 0.021 \textrm(syst.) for jet transverse momenta of 200-400 GeV and 1400-1600 GeV, respectively.