ÚTEFČVUT Ústav technické a experimentální fyziky ČVUT v PrazeInstitute of Experimental and Applied Physics, CTU in Prague

Fast b-tagging at the high-level trigger of the ATLAS experiment in LHC Run 3

NázevTitle
Fast b-tagging at the high-level trigger of the ATLAS experiment in LHC Run 3Fast b-tagging at the high-level trigger of the ATLAS experiment in LHC Run 3
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
G. Aad, B. Abbott, K. Abeling, N. J. Abicht, B. Ali, K. Augsten, B. Bergmann, T. Billoud, H. Day-Hall, Z. Hubáček, P. Jačka, S. Mondal, M. Myška, L. Novotný, V. Petousis, R. Polifka, S. Pospíšil, K. Smolek, A. Sopczak, V. Vacek, P. Vokáč, O. Zaplatílek
Klíčová slovaKeywords
Trigger algorithms, Trigger concepts and systems (hardware and software)
ExperimentCollaboration
ATLAS
DOIDOI
10.1088/1748-0221/18/11/P11006
Časopis / citaceJournal / citation
Journal of Instrumentation 18(11), P11006 (2023) · ISSN 1748-0221
RokYear
2023
JazykLanguage
eng
ZáznamyRecords
ProjektProject
CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026)CERN-CZ III - Výzkumná infrastruktura pro experimenty v CERN - LM2023040 (2023–2026); Institucionální podpora na rozvoj výzkumné org.Institucionální podpora na rozvoj výzkumné org.
CitovánoCited by
42 (INSPIRE-HEP)
2023: 32024: 172025: 152026: 7
Plný text (open access)Full text (open access)
https://iopscience.iop.org/article/10.1088/1748-0221/18/11/P11006/pdf
Citace ke staženíDownload citation
TXT · BibTeX

AbstraktAbstract

The ATLAS experiment relies on real-time hadronic jet reconstruction and b-tagging to record fully hadronic events containing b-jets. These algorithms require track reconstruction, which is computationally expensive and could overwhelm the high-level-trigger farm, even at the reduced event rate that passes the ATLAS first stage hardware-based trigger. In LHC Run 3, ATLAS has mitigated these computational demands by introducing a fast neural-network-based b-tagger, which acts as a low-precision filter using input from hadronic jets and tracks. It runs after a hardware trigger and before the remaining high-level-trigger reconstruction. This design relies on the negligible cost of neural-network inference as compared to track reconstruction, and the cost reduction from limiting tracking to specific regions of the detector. In the case of Standard Model HH -> b (b) over barb (b) over bar, a key signature relying on b-jet triggers, the filter lowers the input rate to the remaining high-level trigger by a factor of five at the small cost of reducing the overall signal efficiency by roughly 2%.

The ATLAS experiment relies on real-time hadronic jet reconstruction and b-tagging to record fully hadronic events containing b-jets. These algorithms require track reconstruction, which is computationally expensive and could overwhelm the high-level-trigger farm, even at the reduced event rate that passes the ATLAS first stage hardware-based trigger. In LHC Run 3, ATLAS has mitigated these computational demands by introducing a fast neural-network-based b-tagger, which acts as a low-precision filter using input from hadronic jets and tracks. It runs after a hardware trigger and before the remaining high-level-trigger reconstruction. This design relies on the negligible cost of neural-network inference as compared to track reconstruction, and the cost reduction from limiting tracking to specific regions of the detector. In the case of Standard Model HH -> b (b) over barb (b) over bar, a key signature relying on b-jet triggers, the filter lowers the input rate to the remaining high-level trigger by a factor of five at the small cost of reducing the overall signal efficiency by roughly 2%.

↑ NahoruTop