1099735 SzGeCERN 20161209235549.0 oai:cds.cern.ch:1099735 cerncds:FULLTEXT SPIRES 8130710 Inspire 807147 ATL-LARG-PUB-2008-002 eng ATL-COM-LARG-2008-003 Lampl, W Calorimeter Clustering Algorithms Description and Performance 2008 Geneva CERN 16 Apr 2008 18 p This note describes the performance of the calorimeter clustering algorithms used for ATLAS, and which provide inputs for particle identification. ATLAS uses two principal algorithms. The first is the ``sliding-window'' algorithm, which clusters calorimeter cells within fixed-size rectangles; results from this are used for electron, photon, and tau lepton identification. The second is the ``topological'' algorithm, which clusters together neighboring cells, as long as the signal in the cells is significant compared to noise. The results of this second algorithm are further used for jet and missing transverse energy reconstruction. This note first summarizes the steps of the calorimeter reconstruction software. A detailed description of the two clustering algorithms is then given. A last section summarizes their performance. The results presented in this note are obtained with the ATLAS athena software releases 12 and 13. PUB CERN EDS SzGeCERN Detectors and Experimental Techniques SzGeCERN Liquid Argon Detector Unit CERN Calorimeter CERN Cluster CERN Clustering CERN LAr CERN Performances CERN Description CERN INTNOTE PUBLATLAS CERN LHC ATLAS Laplace, S Lelas, D Loch, P Ma, H Menke, S Rajagopalan, S Rousseau, D Snyder, S AUTHOR|(CDS)2070388 #BEARD# Unal, G PH-EP http://documents.cern.ch/cgi-bin/setlink?base=atlnot&categ=PUB&id=larg-pub-2008-002 Access to fulltext http://cds.cern.ch/record/1099735/files/larg-pub-2008-002.pdf Access to fulltext http://cds.cern.ch/record/1099735/files/larg-pub-2008-002.ps.gz Access to fulltext laplace@lapp.in2p3.fr n 200870 91 20100906 0951 CER01 20080416 PUBLIC 002753452CER INTNOTEATLASPUBL NOTE