Fast b-tagging at the high-level trigger of the ATLAS experiment in LHC Run 3
Collaboration
37 pages
Published in:
- JINST 18 (2023) 11, P11006
- Published: Nov 10, 2023
e-Print:
- 2306.09738 [hep-ex]
Report number:
- CERN-EP-2023-111
Experiments:
- CERN-LHC-ATLAS,
- CERN-LHC-ATLAS
Citations per year
Abstract: (IOP)
The ATLAS experiment relies on real-time hadronic jetreconstruction and b-tagging to record fully hadronic eventscontaining b-jets. These algorithms require track reconstruction,which is computationally expensive and could overwhelm thehigh-level-trigger farm, even at the reduced event rate that passesthe ATLAS first stage hardware-based trigger. In LHC Run 3, ATLAShas mitigated these computational demands by introducing a fastneural-network-based b-tagger, which acts as a low-precisionfilter using input from hadronic jets and tracks. It runs after ahardware trigger and before the remaining high-level-triggerreconstruction. This design relies on the negligible cost ofneural-network inference as compared to track reconstruction, andthe cost reduction from limiting tracking to specific regions of thedetector. In the case of Standard Model HH → bb̅bb̅, a key signature relying on b-jet triggers, the filter lowers the input rate to the remaininghigh-level trigger by a factor of five at the small cost of reducingthe overall signal efficiency by roughly 2%.Note:
- 37 pages in total, author list starting page 20, 5 figures, 2 tables. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TRIG-2022-03
- Trigger algorithms
- Trigger concepts and systems (hardware and software)
- p p: scattering
- p p: colliding beams
- Higgs particle: pair production
- Higgs particle: hadronic decay
- bottom: pair production
- jet: hadronic
- trigger: hardware
- jet: trigger
References(47)
Figures(9)
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