Showing papers by "Simon George published in 2004"
CERN1, Brookhaven National Laboratory2, Rutherford Appleton Laboratory3, Autonomous University of Barcelona4, University of Alberta5, University of Milan6, University of Genoa7, Sapienza University of Rome8, University of Geneva9, Federal University of Rio de Janeiro10, University College London11, University of London12, University of Wisconsin-Madison13, University of Mannheim14, University of Pavia15, Moscow State University16, University of Liverpool17, Lancaster University18, Helsinki Institute of Physics19, University of Birmingham20, Joseph Fourier University21
01 Feb 2004-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: An overview of the strategy for Event Selection at the ATLAS High Level Trigger is presented and the architecture and main components of the software developed for this purpose are described.
Abstract: We present an overview of the strategy for Event Selection at the ATLAS High Level Trigger and describe the architecture and main components of the software developed for this purpose.
20 citations
TL;DR: Following rigorous software design and analysis methods, an object-based architecture has been developed to derive the second- and third-level trigger decisions for the future ATLAS detector at the LHC.
Abstract: Following rigorous software design and analysis methods, an object-based architecture has been developed to derive the second- and third-level trigger decisions for the future ATLAS detector at the LHC. The functional components within this system responsible for generating elements of the trigger decisions are algorithms running within the software architecture. Relevant aspects of the architecture are reviewed along with concrete examples of specific algorithms and their performance in "vertical" slices of various physics selection strategies.
12 citations
CERN1
TL;DR: In this article, an overview of the current implementation of the selection for electrons and photons in the high level trigger (HLT) is given, in terms of the efficiency for the signal channels, rate expected for the selection, data preparation times, and algorithm execution times.
Abstract: The ATLAS experiment at the Large Hadron Collider (LHC) will face the challenge of efficiently selecting interesting candidate events in pp collisions at 14 TeV center of mass energy, while rejecting the enormous number of background events, stemming from an interaction rate of up to 10/sup 9/ Hz. The Level1 trigger will reduce this rate to around /spl Oscr/(100kHz). Subsequently, the high level trigger (HLT), which is comprised of the Second Level trigger and the Event Filter, will need to reduce this rate further by a factor of /spl Oscr/(10/sup 3/). The HLT selection is software based and will be implemented on commercial CPUs using a common framework built on the standard ATLAS object oriented software architecture. In this paper an overview of the current implementation of the selection for electrons and photons in the HLT is given. The performance of this implementation has been evaluated using Monte Carlo simulations in terms of the efficiency for the signal channels, rate expected for the selection, data preparation times, and algorithm execution times. Besides the efficiency and rate estimates, some physics examples will be discussed, showing that the triggers are well adapted for the physics programme envisaged at LHC. The electron and photon trigger software is also being exercised at the ATLAS 2004 Combined Test Beam, where components from all ATLAS subdetectors are taking data together along the H8 SPS extraction line; from these tests a validation of the selection architecture chosen in a real on-line environment is expected.
3 citations
24 Sep 2004
TL;DR: In this article, an overview of the ATLAS Trigger and Data Acquisition (T/DAQ) system with an emphasis on B physics capabilities is presented. But the authors focus on maintaining the B physics program within some constraints that have arisen: a higher target start-up luminosity, an incomplete configuration of the detector at start up, and cost constraints.
Abstract: This paper gives an overview of the ATLAS Trigger and Data Acquisition (T/DAQ) system with an emphasis on B physics capabilities. It describes recent work on how to maintain the B physics program within some constraints that have arisen: a higher target start‐up luminosity, an incomplete configuration of the detector at start up, and cost constraints for the T/DAQ system. It also shows how the High Level Trigger (HLT) software has advanced and gives some results of new performance measurements.
3 citations