The CMS trigger system

V. Khachatryan , M. Besançon (1) , F. Couderc (1) , M. Dejardin (1) , D. Denegri (1) , B. Fabbro (1) , J.L. Faure (1) , C. Favaro (1) , F. Ferri (1) , S. Ganjour (1) , A. Givernaud (1) , P. Gras (1) , G. Hamel De Monchenault (1) , P. Jarry (1) , E. Locci (1) , M. Machet (1) , J. Malcles (1) , J. Rander (1) , A. Rosowsky (1) , M. Titov (1) , A. Zghiche (1) , I. Antropov (2) , S. Baffioni (2) , F. Beaudette (2) , P. Busson (2) , L. Cadamuro (2) , E. Chapon (2) , C. Charlot (2) , T. Dahms (2) , O. Davignon (2) , N. Filipovic (2) , A. Florent (2) , R. Granier De Cassagnac (2) , S. Lisniak (2) , L. Mastrolorenzo (2) , P. Mine (2) , I.N. Naranjo (2) , M. Nguyen , C. Ochando (2) , G. Ortona (2) , P. Paganini (2) , P. Pigard (2) , S. Regnard (2) , R. Salerno (2) , J.B. Sauvan (2) , Y. Sirois (2) , T. Strebler (2) , Y. Yilmaz (2) , A. Zabi (2) , J.-L. Agram (3) , J. Andrea (3) , A. Aubin (3) , D. Bloch (3) , J.-M. Brom (3) , M. Buttignol (3) , E.C. Chabert (3) , N. Chanon (3) , C. Collard (3) , E. Conte (3) , X. Coubez (3) , J.-C. Fontaine (3) , D. Gele (3) , U. Goerlach (3) , C. Goetzmann (3) , A.-C. Le Bihan (3) , J.A. Merlin (3) , K. Skovpen (3) , P. Van Hove (3) , S. Gadrat (4) , S. Beauceron (5) , C. Bernet (5) , G. Boudoul (5) , E. Bouvier (5) , C.A. Carrillo Montoya (5) , R. Chierici (5) , D. Contardo (5) , B. Courbon (5) , P. Depasse (5) , H. El Mamouni (5) , J. Fan (5) , J. Fay (5) , S. Gascon (5) , M. Gouzevitch (5) , B. Ille (5) , Fabienne Lagarde (5) , I.B. Laktineh (5) , M. Lethuillier (5) , L. Mirabito (5) , A.L. Pequegnot (5) , S. Perries (5) , J.D. Ruiz Alvarez (5) , D. Sabes (5) , L. Sgandurra (5) , V. Sordini (5) , M. Vander Donckt (5) , P. Verdier (5) , S. Viret (5)

1 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
2 LLR - Laboratoire Leprince-Ringuet
3 IPHC - Institut Pluridisciplinaire Hubert Curien
4 CC-IN2P3 - Centre de Calcul de l'IN2P3
5 IPNL - Institut de Physique Nucléaire de Lyon

This paper describes the CMS trigger system and its performance during Run 1 of the LHC. The trigger system consists of two levels designed to select events of potential physics interest from a GHz (MHz) interaction rate of proton-proton (heavy ion) collisions. The first level of the trigger is implemented in hardware, and selects events containing detector signals consistent with an electron, photon, muon, tau lepton, jet, or missing transverse energy. A programmable menu of up to 128 object-based algorithms is used to select events for subsequent processing. The trigger thresholds are adjusted to the LHC instantaneous luminosity during data taking in order to restrict the output rate to 100 kHz, the upper limit imposed by the CMS readout electronics. The second level, implemented in software, further refines the purity of the output stream, selecting an average rate of 400 Hz for offline event storage. The objectives, strategy and performance of the trigger system during the LHC Run 1 are described.

Domaines: Instrumentations et Détecteurs [physics.ins-det]; Physique des Hautes Energies - Expérience [hep-ex]

V. Khachatryan, M. Besançon, F. Couderc, M. Dejardin, D. Denegri, et al.. The CMS trigger system. Journal of Instrumentation, 2017, 12 (01), pp.P01020. ⟨10.1088/1748-0221/12/01/P01020⟩. ⟨in2p3-01362517⟩