362 articles – 2924 references  [version française]
 HAL: in2p3-00754928, version 1
 arXiv: 1211.3055
 Journal of Instrumentation 8 (2013) P04022
 The LHCb Trigger and its Performance in 2011
 R. Aaij, S. Barsuk1, O. Callot1, J. He1, B. Jean-Marie1, J. Lefrançois1, F. Machefert1, A. Martin Sanchez1, M. Nicol1, P. Robbe1, M.-H. Schune1, B. Viaud1, I. Videau1, E. Ben-Haim2, M. Benayoun2, P. David2, L. Del Buono2, A. Martens2, R. Bonnefoy3, H. Chanal3, O. Deschamps3, R. Lefèvre3, L. Li Gioi3, M. Magne3, S. Monteil3, V. Niess3, P. Perret3, E. Aslanides4, J. Cogan4, R. Legac4, O. Leroy4, G. Mancinelli4, M. Perrin-Terrin4, J. Serrano4, C. Drancourt5, I.V. Machikhiliyan5, M.-N. Minard5, B. Pietrzyk5, S. T'Jampens5
 For the LHCb collaboration(s)
 (2013)
 The LHCb trigger and its performance based on data taken at the LHC in 2011 is presented. LHCb is designed to perform flavour physics measurements, and its trigger distinguishes charm and beauty decays from the light quark background. It uses a combination of lepton identification of particles, transverse momentum of particles and selects particles originating from hadrons which decay after a finite flight distance. The trigger reduces the $\sim 11$ MHz of bunch-bunch crossings with at least one non-elastic pp-interaction to 3 kHz of events which are written to storage in two trigger levels. The first level is implemented in hardware, while the next level is a software application which runs on all processors of a large computer farm. A data driven method is used to evaluate the performance of the trigger for several charm and beauty decay modes.
 Subject(s) : Physics/High Energy Physics - Experiment