{
  "id": "1909.00761",
  "version": "v1",
  "published": "2019-09-02T15:15:30.000Z",
  "updated": "2019-09-02T15:15:30.000Z",
  "title": "Performance of electron and photon triggers in ATLAS during LHC Run 2",
  "authors": [
    "ATLAS Collaboration"
  ],
  "comment": "55 pages in total, author list starting page 39, 26 figures, 10 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TRIG-2018-05",
  "categories": [
    "hep-ex"
  ],
  "abstract": "Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for the ATLAS experiment to record signals for a wide variety of physics: from Standard Model processes to searches for new phenomena in both proton-proton and heavy-ion collisions. To cope with a fourfold increase of peak LHC luminosity from 2015 to 2018 (Run 2), to 2.1$\\times$10$^{34}$cm$^{-2}$s$^{-1}$, and a similar increase in the number of interactions per beam-crossing to about 60, trigger algorithms and selections were optimised to control the rates while retaining a high efficiency for physics analyses. For proton-proton collisions, the single-electron trigger efficiency relative to a single-electron offline selection is at least 75% for an offline electron of 31 GeV, and rises to 96% at 60 GeV; the trigger efficiency of a 25 GeV leg of the primary diphoton trigger relative to a tight offline photon selection is more than 96% for an offline photon of 30 GeV. For heavy-ion collisions, the primary electron and photon trigger efficiencies relative to the corresponding standard offline selections are at least 84% and 95%, respectively, at 5 GeV above the corresponding trigger threshold.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-09-02T15:15:30.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "lhc run",
      "trigger efficiency",
      "heavy-ion collisions",
      "performance",
      "photon triggers covering transverse energies"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 55,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}