Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV
Name
Sirunyan_2020_J._Inst._15_P10017.pdf
Description
Published version
Size
2.29 MB
Format
Adobe PDF
Checksum (MD5)
eb09b242c82334b275571cea01b7f4ff
Author(s)
Harris, Philip
Date Issued
2020
Journal
Journal of Instrumentation
Publisher
IOP Publishing
Citation
Harris, Philip. 2020. "Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV." Journal of Instrumentation, 15 (10).
Version
Final published version
Abstract
© 2020 CERN for the benefit of the CMS collaboration. 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 × 1034 cm-2s-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.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/1748-0221/15/10/P10017
