Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV
© 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 R...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2022
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| Online Access: | https://hdl.handle.net/1721.1/142116 |
| _version_ | 1811071511698604032 |
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| author | Harris, Philip |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Harris, Philip |
| author_sort | Harris, Philip |
| collection | MIT |
| description | © 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. |
| first_indexed | 2024-09-23T08:52:20Z |
| format | Article |
| id | mit-1721.1/142116 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:52:20Z |
| publishDate | 2022 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1421162023-12-20T16:48:22Z Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV Harris, Philip Massachusetts Institute of Technology. Department of Physics © 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. 2022-04-26T18:57:58Z 2022-04-26T18:57:58Z 2020 2022-04-26T18:49:40Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/142116 Harris, Philip. 2020. "Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV." Journal of Instrumentation, 15 (10). en 10.1088/1748-0221/15/10/P10017 Journal of Instrumentation Creative Commons Attribution 4.0 International license https://creativecommons.org/licenses/by/4.0/ application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Harris, Philip Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV |
| title | Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV |
| title_full | Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV |
| title_fullStr | Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV |
| title_full_unstemmed | Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV |
| title_short | Performance of the CMS Level-1 trigger in proton-proton collisions at √ s = 13 TeV |
| title_sort | performance of the cms level 1 trigger in proton proton collisions at √ s 13 tev |
| url | https://hdl.handle.net/1721.1/142116 |
| work_keys_str_mv | AT harrisphilip performanceofthecmslevel1triggerinprotonprotoncollisionsats13tev |