Speaker
Andrea Ventura
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
Description
The ATLAS experiment CERN's Large Hadron Collider has been projected and realized for new discoveries in High Energy Physics as well as for precision measurements of Standard Model parameters. To satisfy the limited data acquisition capability, at the LHC project luminosity, the ATLAS trigger system will have to select a very small rate of physically interesting events (~200 Hz) among about 40 million events per second.
In the case of events containing muons, as described in this work, the first hardware-based level (LVL1) starts from measurements of the Muon Spectrometer trigger chambers to select Regions of Interest (RoI) where muons produce significant activity. Such RoIs are used as seeds for the two subsequent trigger levels (LVL2 and Event Filter), running on dedicated online farms, which constitute the High Level Trigger (HLT). This seeding strategy is crucial to drastically reduce the total processing time.
Within the Muon HLT, few algorithms are implemented in different steps according to predefined sequences of Feature Extraction (FEX) and Hypothesis (HYPO) algorithms, whose goal is to validate the previously selected muon objects. The ATLAS muon trigger system, thanks to its particular design and to the peculiar structure of the Muon Spectrometer, is able to provide muon stand-alone event trigger decisions, that can be furtherly refined by exploiting the muon information coming from the other ATLAS subdetectors. Muon HLT algorithms are described here in terms of working functionality and performance (memory leaks, data volume, code testing and validation) both on simulated and real data, including non-standard trigger configurations (like cosmic data and LHC start-up scenarios).
Primary author
Andrea Ventura
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
Co-authors
Akimasa Ishikawa
(Kobe University, Kobe)
Aleandro Nisati
(INFN Roma I)
Alessandro Di Mattia
(Michigan State University, Department of Physics and Astronomy, East Lansing, Michigan)
Andrea Negri
(INFN Pavia, Universita' di Pavia, Dipartimento di Fisica Nucleare e Teorica, Pavia)
Antonio Sidoti
(INFN Roma I)
Attila Krasznahorkay
(European Laboratory for Particle Physics (CERN), Geneva and University of Debrecen)
Carlo Dionisi
(INFN Roma, Universita' di Roma "La Sapienza", Dipartimento di Fisica, Roma)
Chihiro Omachi
(Kobe University, Kobe)
Claudio Luci
(INFN Roma, Universita' di Roma "La Sapienza", Dipartimento di Fisica, Roma)
Diana Scannicchio
(European Laboratory for Particle Physics (CERN), Geneva)
Edoardo Gorini
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
Enrico Pasqualucci
(INFN Roma I)
Francesco Conventi
(INFN Napoli)
Francesco Marzano
(INFN Roma I)
Gabriella Cataldi
(INFN Lecce)
Gianpaolo Carlino
(INFN Napoli)
Giovanni Siragusa
(Institut fur Physik, Universitat Mainz, Mainz)
Giulio Usai
(University of Chicago, Enrico Fermi Institute, Chicago, Illinois)
Hironori Kijamura
(Kobe University, Kobe)
Hisaya Kurasige
(Kobe University, Kobe)
Katsuo Tokushuku
(KEK, High Energy Accelerator Research Organisation, Tsukuba)
Kenji Ozone
(KEK, High Energy Accelerator Research Organisation, Tsukuba)
Kunihiro Nagano
(KEK, High Energy Accelerator Research Organisation, Tsukuba)
Lamberto Luminari
(INFN Roma I)
Marco Rescigno
(INFN Roma I)
Margherita Primavera
(INFN Lecce)
Masaya Ishino
(International Center for Elementary Particle Physics, University of Tokyo, Tokyo)
Massimiliano Bellomo
(INFN Pavia)
Michela Biglietti
(INFN Napoli, Universita' di Napoli "Federico II", Dipartimento di Scienze Fisiche, Napoli)
Naoko Kanaya
(International Center for Elementary Particle Physics, University of Tokyo, Tokyo)
Natalia Panikashvili
(University of Michigan, Department of Physics, Ann Arbor, Michigan)
Roberto Crupi
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
Ryan Patrick
(Michigan State University, Department of Physics and Astronomy, East Lansing, Michigan)
Sergio Grancagnolo
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
Shlomit Tarem
(Department of Physics, Technion, Haifa)
Speranza Falciano
(INFN Roma I)
Stefania Spagnolo
(INFN Lecce, Universita' degli Studi del Salento, Dipartimento di Fisica, Lecce)
Stefano Giagu
(INFN Roma, Universita' di Roma "La Sapienza", Dipartimento di Fisica, Roma)
Takanori Kono
(European Laboratory for Particle Physics (CERN), Geneva)
Takashi Kubota
(International Center for Elementary Particle Physics, University of Tokyo, Tokyo)
Takuya Hori
(Kobe University, Kobe)
Valerio Vercesi
(INFN Pavia)
Yuji Yamazaki
(Kobe University, Kobe)
Zvi Tarem
(Department of Physics, Technion, Haifa)
