001055569 001__ 1055569
001055569 003__ SzGeCERN
001055569 005__ 20220817153553.0
001055569 0247_ $$2DOI$$a10.1088/1742-6596/119/2/022029
001055569 0248_ $$aoai:cds.cern.ch:1055569$$pcerncds:FULLTEXT$$pcerncds:CERN:FULLTEXT$$pcerncds:CERN
001055569 035__ $$9Inspire$$a803019
001055569 037__ $$aATL-DAQ-CONF-2007-025
001055569 041__ $$aeng
001055569 088__ $$aATL-COM-DAQ-2007-028
001055569 100__ $$aConde-Muíño, P$$uLisbon, LIFEP
001055569 245__ $$aImplementation and Performance of the ATLAS Second Level Jet Trigger
001055569 260__ $$c2008
001055569 269__ $$aGeneva$$bCERN$$c10 Sep 2007
001055569 300__ $$a7 p
001055569 520__ $$aATLAS is one of the four major LHC experiments, designed to cover a wide range of physics topics. In order to cope with a rate of 40 MHz and 25 interactions per bunch crossing, the ATLAS trigger system is divided in three different levels. The first one (LVL1, hardware based) identifies signatures in 2 microseconds that are confirmed by the the following trigger levels (software based). The Second Level Trigger (LVL2) only looks at a region of the space around the LVL1 signature (called Region of Interest or ROI), confirming/rejecting the event in about 10 ms, while the Event Filter (Third Level Trigger, EF) has potential full event access and larger processing times, of the order of 1 s. The jet selection starts at the LVL1 with dedicated processors that search for high ET hadronic energy depositions. At the LVL2, the jet signatures are verified with the execution of a dedicated, fast jet reconstruction algorithm. Given the fact that the main jet's background are jets,the energy calibration at the LVL2 is one of the major dificulties of this trigger, allowing to distinguish low/high energy jets. The algorithm for the calibration has been chosen to be fast and robust, with a good performance. The other major dificulty is the execution time of the algorithm,dominated by the data unpacking time due to the large sizes of the jet ROI. In order to reduce the execution time, three possible granularities have been proposed and are being evaluated: cell based (standard), energy sums calculated at each Fron-End Board (FEB) and the use of the LVL1 Trigger Towers. The FEB and Trigger Tower granularities are also being used/evaluated for the reconstruction of the missing ET triggers at the Event Filter, given the short times available to process the full event. In this presentation, the design and implementation of the jet trigger of ATLAS will be discussed in detail, emphasasing the major dificulties of each selection step. The performance of the jet algorithm, including timing, eficiencies and rates will also be shown, with detailed comparisons of the different unpacking modes.
001055569 540__ $$3publication$$aCC-BY
001055569 594__ $$aCONF
001055569 595__ $$aCERN EDS
001055569 65017 $$2SzGeCERN$$aDetectors and Experimental Techniques
001055569 65027 $$2SzGeCERN$$aDAQ and Trigger
001055569 6531_ $$9CERN$$ajet, trigger
001055569 690C_ $$aCERN
001055569 690C_ $$aINTNOTE
001055569 690C_ $$aPUBLATLAS
001055569 690C_ $$aARTICLE
001055569 690C_ $$aINTNOTEATLASPRIV
001055569 693__ $$aCERN LHC$$eATLAS
001055569 700__ $$aAracena, I$$uSLAC
001055569 700__ $$aBrelier, B$$uMontreal U.
001055569 700__ $$aCranmer, K$$uBrookhaven
001055569 700__ $$aDelsart, P A$$uMontreal U.
001055569 700__ $$aDufour, M A$$uMcGill U.
001055569 700__ $$aEckweiler, S$$uMainz U., Inst. Phys.
001055569 700__ $$aFerland, J$$uMontreal U.
001055569 700__ $$0AUTHOR|(CDS)2077905$$9#BEARD#$$aIdarraga, J$$uMontreal U.
001055569 700__ $$0AUTHOR|(CDS)2070655$$9#BEARD#$$aJohns, K$$uArizona U.
001055569 700__ $$0AUTHOR|(CDS)2071403$$9#BEARD#$$aLeCompte, T$$uArgonne
001055569 700__ $$aPotter, C$$uMcGill U.
001055569 700__ $$aRobertson, S$$uMcGill U.
001055569 700__ $$aSantamarina-Rios, C$$uMcGill U.
001055569 700__ $$aSegura, E$$uBarcelona, IFAE
001055569 700__ $$aSilverstein, D$$uSLAC
001055569 700__ $$aVachon, B$$uMcGill U.
001055569 710__ $$5PH-EP
001055569 711__ $$aInternational Conference on Computing in High Energy and Nuclear Physics
001055569 773__ $$c022029$$pJ. Phys.: Conf. Ser.$$v119$$y2008
001055569 859__ $$fPatricia.Conde.Muino@cern.ch
001055569 8564_ $$uhttp://documents.cern.ch/cgi-bin/setlink?base=atlnot&categ=CONF&id=daq-conf-2007-025$$yAccess to fulltext
001055569 8564_ $$uhttps://cds.cern.ch/record/1055569/files/daq-conf-2007-025.pdf$$yAccess to fulltext
001055569 8564_ $$uhttps://cds.cern.ch/record/1055569/files/daq-conf-2007-025.ps.gz$$yAccess to fulltext
001055569 8564_ $$uhttps://cds.cern.ch/record/1055569/files/poster_chep07_conde.pdf$$yAccess to fulltext
001055569 916__ $$sn$$w200770
001055569 960__ $$a13
001055569 961__ $$c20100601$$h1529$$lCER01$$x20070910
001055569 963__ $$aPUBLIC
001055569 962__ $$b947732$$k022029$$nvictoria20070902
001055569 970__ $$a002712176CER
001055569 980__ $$aARTICLE
001055569 980__ $$aConferencePaper