{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/30962"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/30962","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Measurement of the top anti-top quark pair production cross section in the dilepton decay channel using Lepton+Track selection in 7 TeV p − p collisions with L = 698 PB−1","abstract":"We present measurements of the t¯t production cross section obtained using the ATLAS detector at the LHC with pp collisions at √s = 7 TeV in dilepton final states, from a data sample of L=698 pb−1 taken in 2011. For dilepton pair selection we have used a ‘Lepton+Track’ approach, where selection requirements on one lepton leg are reduced to a requirement of only a high quality Inner Detector track. This proce- dure, while allowing more background in the selected sample, enhances the sensitivity to τ-leptonic decays of the W± and increases the t¯t acceptance by 20% over the conventional dilepton analysis (where each lepton is identified as an electron or muon). Two modes of the l+track analysis were studied: the inclu- sive and the exclusive mode. The measured t¯t cross sections in the inclusive eTL and μTL channels are 182.9±9.3 (stat.)+21.9 −16.7 (syst.)+8.2 −7.3 (lum.) pb and 171.0±8.5 (stat.)+20.6 −17.5 (syst.)+7.8 −7.0 (lum.) pb, respectively. The inclusive eTL and μTL combined t¯t cross section is 177.4±6.3 (stat.)+18.4 −15.2 (syst.)±7.6 (lum.) pb. The mea- sured t¯t cross sections in the exclusive eTL and μTL channels are 160.8 ±22.6 (syst.)+45.1 −33.1 (syst.)+8.3 −6.8 (lum.) pb and 168.3 ± 23.9 (syst.)+45.8 −39.0 (syst.)+9.0 −7.5 (lum.) pb, respectively. The exclusive eTL and μTL combined t¯t cross section is 164.5 ± 16.4 (syst.)+39.0 −30.5 (syst.)+8.6 −7.1 (lum.) pb. These t¯t cross section measurements are consistent with each other and are in good agreement with the Standard Model prediction of 164.6+11.5 −15.8 pb.","abstract_html":"We present measurements of the t¯t production cross section obtained using the ATLAS detector at the LHC with pp collisions at √s = 7 TeV in dilepton final states, from a data sample of L=698 pb−1 taken in 2011. For dilepton pair selection we have used a ‘Lepton+Track’ approach, where selection requirements on one lepton leg are reduced to a requirement of only a high quality Inner Detector track. This proce- dure, while allowing more background in the selected sample, enhances the sensitivity to τ-leptonic decays of the W± and increases the t¯t acceptance by 20% over the conventional dilepton analysis (where each lepton is identified as an electron or muon). Two modes of the l+track analysis were studied: the inclu- sive and the exclusive mode. The measured t¯t cross sections in the inclusive eTL and μTL channels are 182.9±9.3 (stat.)+21.9 −16.7 (syst.)+8.2 −7.3 (lum.) pb and 171.0±8.5 (stat.)+20.6 −17.5 (syst.)+7.8 −7.0 (lum.) pb, respectively. The inclusive eTL and μTL combined t¯t cross section is 177.4±6.3 (stat.)+18.4 −15.2 (syst.)±7.6 (lum.) pb. The mea- sured t¯t cross sections in the exclusive eTL and μTL channels are 160.8 ±22.6 (syst.)+45.1 −33.1 (syst.)+8.3 −6.8 (lum.) pb and 168.3 ± 23.9 (syst.)+45.8 −39.0 (syst.)+9.0 −7.5 (lum.) pb, respectively. The exclusive eTL and μTL combined t¯t cross section is 164.5 ± 16.4 (syst.)+39.0 −30.5 (syst.)+8.6 −7.1 (lum.) pb. These t¯t cross section measurements are consistent with each other and are in good agreement with the Standard Model prediction of 164.6+11.5 −15.8 pb.","abstract_has_math":false,"creators":["Khandanyan, Hovhannes"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Errede, Steven M.","Wiss, J.E.","Stack, John D.","Cooper, S. Lance"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-05-22T00:18:41Z","date_published":"2012-05-22T00:18:41Z","updated_at":"2026-07-22T22:25:29Z","subjects":["Cross Section","Cross Section Measurement","Lepton+Track","Track-Lepton","ATLAS Cross Section","ATLAS Thesis","UIUC Thesis","UIUC ATLAS","Hovhannes","Khandanyan","Hovhannes Khandanyan Thesis","Hovhannes Khandanyan Dissertation","University of Illinois Champaign-Urbana (UIUC)"],"languages":["en"],"rights":["Copyright 2012 by Hovhannes Khandanyan. All rights reserved."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/30962","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Errede, Steven M.","Wiss, J.E.","Stack, John D.","Cooper, S. 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All rights reserved."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/30962"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We present measurements of the t¯t production cross section obtained using the ATLAS detector at the LHC with pp collisions at √s = 7 TeV in dilepton final states, from a data sample of L=698 pb−1 taken in 2011. For dilepton pair selection we have used a ‘Lepton+Track’ approach, where selection requirements on one lepton leg are reduced to a requirement of only a high quality Inner Detector track. This proce- dure, while allowing more background in the selected sample, enhances the sensitivity to τ-leptonic decays of the W± and increases the t¯t acceptance by 20% over the conventional dilepton analysis (where each lepton is identified as an electron or muon). Two modes of the l+track analysis were studied: the inclu- sive and the exclusive mode. The measured t¯t cross sections in the inclusive eTL and μTL channels are 182.9±9.3 (stat.)+21.9 −16.7 (syst.)+8.2 −7.3 (lum.) pb and 171.0±8.5 (stat.)+20.6 −17.5 (syst.)+7.8 −7.0 (lum.) pb, respectively. The inclusive eTL and μTL combined t¯t cross section is 177.4±6.3 (stat.)+18.4 −15.2 (syst.)±7.6 (lum.) pb. The mea- sured t¯t cross sections in the exclusive eTL and μTL channels are 160.8 ±22.6 (syst.)+45.1 −33.1 (syst.)+8.3 −6.8 (lum.) pb and 168.3 ± 23.9 (syst.)+45.8 −39.0 (syst.)+9.0 −7.5 (lum.) pb, respectively. The exclusive eTL and μTL combined t¯t cross section is 164.5 ± 16.4 (syst.)+39.0 −30.5 (syst.)+8.6 −7.1 (lum.) pb. These t¯t cross section measurements are consistent with each other and are in good agreement with the Standard Model prediction of 164.6+11.5 −15.8 pb.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2012-03-20T19:21:04Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Khandanyan_Hovhannes.pdf: 6087362 bytes, checksum: 0aec8f55446734e8e0bcdb13c18f5dfc (MD5)","Made available in DSpace on 2012-05-22T00:18:41Z (GMT). No. of bitstreams: 2 Khandanyan_Hovhannes.pdf: 6087362 bytes, checksum: 0aec8f55446734e8e0bcdb13c18f5dfc (MD5) license.txt: 4070 bytes, checksum: 095a57c6936c3180cc0eeaceba63ecca (MD5)"]},{"key":"dc:title","label":"Title","values":["Measurement of the top anti-top quark pair production cross section in the dilepton decay channel using Lepton+Track selection in 7 TeV p − p collisions with L = 698 PB−1"]}]}],"canonical_facts":{"dc:contributor":["Errede, Steven M.","Wiss, J.E.","Stack, John D.","Cooper, S. Lance"],"dc:creator":["Khandanyan, Hovhannes"],"dc:date":["2012-05-22T00:18:41Z","2012-05"],"dc:description":["We present measurements of the t¯t production cross section obtained using the ATLAS detector at the LHC with pp collisions at √s = 7 TeV in dilepton final states, from a data sample of L=698 pb−1 taken in 2011. For dilepton pair selection we have used a ‘Lepton+Track’ approach, where selection requirements on one lepton leg are reduced to a requirement of only a high quality Inner Detector track. This proce- dure, while allowing more background in the selected sample, enhances the sensitivity to τ-leptonic decays of the W± and increases the t¯t acceptance by 20% over the conventional dilepton analysis (where each lepton is identified as an electron or muon). Two modes of the l+track analysis were studied: the inclu- sive and the exclusive mode. The measured t¯t cross sections in the inclusive eTL and μTL channels are 182.9±9.3 (stat.)+21.9 −16.7 (syst.)+8.2 −7.3 (lum.) pb and 171.0±8.5 (stat.)+20.6 −17.5 (syst.)+7.8 −7.0 (lum.) pb, respectively. The inclusive eTL and μTL combined t¯t cross section is 177.4±6.3 (stat.)+18.4 −15.2 (syst.)±7.6 (lum.) pb. The mea- sured t¯t cross sections in the exclusive eTL and μTL channels are 160.8 ±22.6 (syst.)+45.1 −33.1 (syst.)+8.3 −6.8 (lum.) pb and 168.3 ± 23.9 (syst.)+45.8 −39.0 (syst.)+9.0 −7.5 (lum.) pb, respectively. The exclusive eTL and μTL combined t¯t cross section is 164.5 ± 16.4 (syst.)+39.0 −30.5 (syst.)+8.6 −7.1 (lum.) pb. These t¯t cross section measurements are consistent with each other and are in good agreement with the Standard Model prediction of 164.6+11.5 −15.8 pb.","Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2012-03-20T19:21:04Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Khandanyan_Hovhannes.pdf: 6087362 bytes, checksum: 0aec8f55446734e8e0bcdb13c18f5dfc (MD5)","Made available in DSpace on 2012-05-22T00:18:41Z (GMT). No. of bitstreams: 2 Khandanyan_Hovhannes.pdf: 6087362 bytes, checksum: 0aec8f55446734e8e0bcdb13c18f5dfc (MD5) license.txt: 4070 bytes, checksum: 095a57c6936c3180cc0eeaceba63ecca (MD5)"],"dc:identifier":["http://hdl.handle.net/2142/30962"],"dc:language":["en"],"dc:rights":["Copyright 2012 by Hovhannes Khandanyan. All rights reserved."],"dc:subject":["Cross Section","Cross Section Measurement","Lepton+Track","Track-Lepton","ATLAS Cross Section","ATLAS Thesis","UIUC Thesis","UIUC ATLAS","Hovhannes","Khandanyan","Hovhannes Khandanyan Thesis","Hovhannes Khandanyan Dissertation","University of Illinois Champaign-Urbana (UIUC)"],"dc:title":["Measurement of the top anti-top quark pair production cross section in the dilepton decay channel using Lepton+Track selection in 7 TeV p − p collisions with L = 698 PB−1"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:29Z"}