Commissioning of the CMS High Level Trigger

Lorenzo Agostino; Gerry Bauer; Barbara Beccati; Ulf Behrens; Jeffrey Berryhil; Kurt Biery; Tulika Bose; Angela Brett; James Branson; Eric Cano; Harry Cheung; Marek Ciganek; Sergio Cittolin; Jose Antonio Coarasa; Bryan Dahmes; Christian Deldicque; Elizabeth Dusinberre; Samim Erhan; Dominique Gigi; Frank Glege; Robert Gomez-Reino; Johannes Gutleber; Derek Hatton; Jean-Francois Laurens; Constantin Loizides; Frank Ma; Frans Meijers; Emilio Meschi; Andreas Meyer; Remigius K. Mommsen; Roland Moser; Vivian O'Dell; Alexander Oh; Luciano Orsini; Vaios Patras; Christoph Paus; Andrea Petrucci; Marco Pieri; Attila Racz; Hannes Sakulin; Matteo Sani; Philipp Schieferdeckerd; Christoph Schwick; Josep Francesc Serrano Margaleff; Dennis Shpakov; Sean Simon; Konstanty Sumorok; Andre Sungho Yoon; Peter Wittich; Marco Zanetti

doi:10.1088/1748-0221/4/10/p10005

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arXiv · 0908.1065

Commissioning of the CMS High Level Trigger

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Abstract

The CMS experiment will collect data from the proton-proton collisions delivered by the Large Hadron Collider (LHC) at a centre-of-mass energy up to 14 TeV. The CMS trigger system is designed to cope with unprecedented luminosities and LHC bunch-crossing rates up to 40 MHz. The unique CMS trigger architecture only employs two trigger levels. The Level-1 trigger is implemented using custom electronics, while the High Level Trigger (HLT) is based on software algorithms running on a large cluster of commercial processors, the Event Filter Farm. We present the major functionalities of the CMS High Level Trigger system as of the starting of LHC beams operations in September 2008. The validation of the HLT system in the online environment with Monte Carlo simulated data and its commissioning during cosmic rays data taking campaigns are discussed in detail. We conclude with the description of the HLT operations with the first circulating LHC beams before the incident occurred the 19th September 2008.

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Lorenzo Agostino, Gerry Bauer, Barbara Beccati, Ulf Behrens, Jeffrey Berryhil, Kurt Biery, Tulika Bose, Angela Brett, James Branson, Eric Cano, Harry Cheung, Marek Ciganek, Sergio Cittolin, Jose Antonio Coarasa, Bryan Dahmes, Christian Deldicque, Elizabeth Dusinberre, Samim Erhan, Dominique Gigi, Frank Glege, Robert Gomez-Reino, Johannes Gutleber, Derek Hatton, Jean-Francois Laurens, Constantin Loizides, Frank Ma, Frans Meijers, Emilio Meschi, Andreas Meyer, Remigius K. Mommsen, Roland Moser, Vivian O'Dell, Alexander Oh, Luciano Orsini, Vaios Patras, Christoph Paus, Andrea Petrucci, Marco Pieri, Attila Racz, Hannes Sakulin, Matteo Sani, Philipp Schieferdeckerd, Christoph Schwick, Josep Francesc Serrano Margaleff, Dennis Shpakov, Sean Simon, Konstanty Sumorok, Andre Sungho Yoon, Peter Wittich, Marco Zanetti. 2009-08-07. Commissioning of the CMS High Level Trigger. https://doi.org/10.1088/1748-0221/4/10/p10005

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