001647616 001__ 1647616
001647616 005__ 20150211084029.0
001647616 0248_ $$aoai:cds.cern.ch:1647616$$pcerncds:atlas-conf$$pcerncds:FULLTEXT
001647616 035__ $$9Inspire$$a1281302
001647616 037__ $$aATLAS-CONF-2014-002
001647616 041__ $$aeng
001647616 088__ $$9ATLAS-COM-CONF-2013-002
001647616 110__ $$aThe ATLAS collaboration
001647616 245__ $$aThe ATLAS transverse-momentum trigger performance at the LHC in 2011
001647616 260__ $$c2014
001647616 269__ $$aGeneva$$bCERN$$c11 Feb 2014
001647616 300__ $$a29 p
001647616 520__ $$aThe transverse momentum triggers of the ATLAS experiment at the CERN Large Hadron Collider are designed to select events with non-interacting particles passing through the detector and events with a large amount of outgoing momentum transverse to the beam axis. These triggers use global sums over the full calorimeter so are sensitive to measurement fluctuations and systematic changes anywhere in the detector. During the 2011 data-taking period, the LHC beam conditions for proton-proton collisions went through considerable evolution, starting with an average number of interactions per bunch crossing in a run, <mu>, of about 3, increasing to typical values of 7 to 15, and even including one run with <mu> of about 30. These changes were accompanied by changes in the bunch structure, including the number of filled bunches, how these were spaced, and the intensity of individual bunches. An increase in mu results in an increase of both the average energy deposit in the calorimeter and the energy-measurement fluctuations. Changes in beam conditions in turn necessitated changes in the calorimeter noise-suppression schemes used at various trigger levels. Transverse momentum distributions and trigger rates were impacted by all of these changes. This note contains a description of the transverse momentum triggers, the challenges faced in the 2011 data-taking period, the strategies used to deal with changes in the beam and detector, and characterization of the trigger performance in 2011. Even under these conditions, the trigger behavior was close to what was expected and allowed robust collection of data used for physics studies.
001647616 594__ $$aCONF
001647616 595__ $$aCERN CDS-Invenio WebSubmit
001647616 65017 $$2SzGeCERN$$aDetectors and Experimental Techniques
001647616 65027 $$2SzGeCERN$$aConference talks on ATLAS
001647616 6531_ $$9CERN$$aTrigger
001647616 6531_ $$9CERN$$aTransverse momentum
001647616 6531_ $$9CERN$$aMET
001647616 690C_ $$aCERN
001647616 690C_ $$aINTNOTE
001647616 690C_ $$aINTNOTEATLASPUBL
001647616 693__ $$aCERN LHC$$eATLAS
001647616 710__ $$5PH-EP
001647616 8564_ $$uhttps://cds.cern.ch/record/1505363$$yOriginal Communication (restricted to ATLAS)
001647616 8564_ $$uhttps://cds.cern.ch/record/1647616/files/ATLAS-CONF-2014-002.pdf$$zStamped by WebSubmit: 11/02/2014
001647616 859__ $$fallen.mincer@nyu.edu
001647616 859__ $$fflorian.bernlochner@gmail.com
001647616 916__ $$sn$$w201470
001647616 960__ $$a91
001647616 963__ $$aPUBLIC
001647616 970__ $$a000736759CER
001647616 980__ $$aINTNOTEATLASPUBL
001647616 980__ $$aNOTE