Performance of the CMS high-level trigger during LHC Run 2
A. Hayrapetyan, A. Tumasyan, W. Adam, Janik Walter Andrejkovic, L. Benato, T. Bergauer, S. Chatterjee, K. Damanakis, M. Dragicevic, Priya Sajid Hussain, M. Jeitler, Natascha Krammer, A. Li, D. Liko, I. Mikulec, J. Schieck, R. Schöfbeck, D. Schwarz, M. Sonawane, W. Waltenberger, C.-E. Wulz, X. Janssen, T. Van Laer, P. Van Mechelen, Nordin Breugelmans, J. D’Hondt, Soumya Dansana, A. De Moor, M. Delcourt, Felix Heyen, S. Lowette, I. Makarenko, D. Müller, S. Tavernier, M. Tytgat, G. P. Van Onsem, S. Van Putte, D. Vannerom, D. Beghin, B. Bilin, H. Brun, B. Clerbaux, A. Das, I. De Bruyn, G. De Lentdecker, Hugues Evard, L. Favart, P. Gianneios, J. Jaramillo, Ali Khalilzadeh, Fakhri Alam Khan, K. Lee, A. Malara, S. Paredes, M. A. Shahzad, Laurent Thomas, M. Vanden Bemden, C. Vander Velde, P. Vanlaer, T. Cornelis, M. De Coen, D. Dobur, G. Gökbulut, Y. Hong, J. Knolle, Luka Lambrecht, David Marckx, K. Mota Amarilo, K. Skovpen, N. Van Den Bossche, Jan van der Linden, Liam Wezenbeek, A. Benecke, A. Bethani, G. Bruno, C. Caputo, J. De Favereau De Jeneret, C. Delaere, I. S. Donertas, A. Giammanco, Ahmet Oguz Guzel, Sa. Jain, V. Lemaitre, J. Lidrych, Paola Mastrapasqua, T. T. Tran, S. Turkcapar, G. A. Alves, E. Coelho, G. Correia Silva, C. Hensel, T. Menezes De Oliveira, C. Mora Herrera, P. Rebello Teles, M. Soeiro, E. J. Tonelli Manganote, A. Vilela Pereira, W. L. Aldá Júnior, M. Barroso Ferreira Filho, H. Brandao Malbouisson
Abstract
Abstract The CERN LHC provided proton and heavy ion collisions during its Run 2 operation period from 2015 to 2018. Proton-proton collisions reached a peak instantaneous luminosity of 2.1× 10 34 cm -2 s -1 , twice the initial design value, at √( s )=13 TeV. The CMS experiment records a subset of the collisions for further processing as part of its online selection of data for physics analyses, using a two-level trigger system: the Level-1 trigger, implemented in custom-designed electronics, and the high-level trigger, a streamlined version of the offline reconstruction software running on a large computer farm. This paper presents the performance of the CMS high-level trigger system during LHC Run 2 for physics objects, such as leptons, jets, and missing transverse momentum, which meet the broad needs of the CMS physics program and the challenge of the evolving LHC and detector conditions. Sophisticated algorithms that were originally used in offline reconstruction were deployed online. Highlights include a machine-learning b tagging algorithm and a reconstruction algorithm for tau leptons that decay hadronically.