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Performance of the CMS Level-1 trigger in proton-proton collisions at √s = 13 TeV

CMS Collaboration; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Ambrogi, F.; Arnold, B.; Bergauer, H.; Bergauer, T.; Dragicevic, M.; Erö, J.; Valle, A. Escalante Del; Flechl, M.; Frühwirth, R.; Jeitler, M.; Krammer, N.; Krätschmer, I.; Liko, D.; Madlener, T.; Mikulec, I.; Rad, N.; Schieck, J.; ... mehr

At the start of Run 2 in 2015, the LHC delivered proton-proton collisions at a center-of-mass energy of 13\TeV. During Run 2 (years 2015–2018) the LHC eventually reached a luminosity of 2.1× 10$^{34}$ cm$^{-2}$s$^{-1}$, almost three times that reached during Run 1 (2009–2013) and a factor of two larger than the LHC design value, leading to events with up to a mean of about 50 simultaneous inelastic proton-proton collisions per bunch crossing (pileup). The CMS Level-1 trigger was upgraded prior to 2016 to improve the selection of physics events in the challenging conditions posed by the second run of the LHC. This paper describes the performance of the CMS Level-1 trigger upgrade during the data taking period of 2016–2018. The upgraded trigger implements pattern recognition and boosted decision tree regression techniques for muon reconstruction, includes pileup subtraction for jets and energy sums, and incorporates pileup-dependent isolation requirements for electrons and tau leptons. In addition, the new trigger calculates high-level quantities such as the invariant mass of pairs of reconstructed particles. The upgrade reduces the trigger rate from background processes and improves the trigger efficiency for a wide variety of physics signals.

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Verlagsausgabe §
DOI: 10.5445/IR/1000131039
Veröffentlicht am 01.04.2021
DOI: 10.1088/1748-0221/15/10/P10017
Zitationen: 1
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Experimentelle Kernphysik (IEKP)
Institut für Experimentelle Teilchenphysik (ETP)
Institut für Kernphysik (IKP)
Steinbuch Centre for Computing (SCC)
Institut für Prozessdatenverarbeitung und Elektronik (IPE)
Publikationstyp Zeitschriftenaufsatz
Publikationsmonat/-jahr 10.2020
Sprache Englisch
Identifikator ISSN: 1748-0221
KITopen-ID: 1000131039
Erschienen in Journal of Instrumentation
Verlag IOP Publishing
Band 15
Heft 10
Seiten Art.-Nr. P10017
Vorab online veröffentlicht am 19.10.2020
Schlagwörter Large detector-systems performance; Trigger algorithms
Nachgewiesen in Scopus
Web of Science
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