Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector
A search for pair production of vector-like quarks, both up-type (T) and down-type (B), as well as for four-top-quark production, is presented. The search is based on pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and correspondin...
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| Format: | Article |
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Springer Berlin Heidelberg
2018
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| Online Access: | http://hdl.handle.net/1721.1/116505 https://orcid.org/0000-0002-7586-7253 |
| _version_ | 1826214362220593152 |
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| author | ATLAS Collaboration Taylor, Frank E |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics ATLAS Collaboration Taylor, Frank E |
| author_sort | ATLAS Collaboration |
| collection | MIT |
| description | A search for pair production of vector-like quarks, both up-type (T) and down-type (B), as well as for four-top-quark production, is presented. The search is based on pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 20.3 fb ⁻¹. Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets. Dedicated analyses are performed targeting three cases: a T quark with significant branching ratio to a W boson and a b-quark (TT¯→Wb+X), and both a T quark and a B quark with significant branching ratio to a Higgs boson and a third-generation quark (TT¯→Ht+XandBB¯→Hb+X respectively). No significant excess of events above the Standard Model expectation is observed, and 95% CL lower limits are derived on the masses of the vector-like T and B quarks under several branching ratio hypotheses assuming contributions from T → Wb, Zt, Ht and B → Wt, Zb, Hb decays. The 95% CL observed lower limits on the T quark mass range between 715 GeV and 950 GeV for all possible values of the branching ratios into the three decay modes, and are the most stringent constraints to date. Additionally, the most restrictive upper bounds on four-top-quark production are set in a number of new physics scenarios. |
| first_indexed | 2024-09-23T16:03:51Z |
| format | Article |
| id | mit-1721.1/116505 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T16:03:51Z |
| publishDate | 2018 |
| publisher | Springer Berlin Heidelberg |
| record_format | dspace |
| spelling | mit-1721.1/1165052022-09-29T18:01:00Z Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector ATLAS Collaboration Taylor, Frank E Massachusetts Institute of Technology. Department of Physics Taylor, Frank E A search for pair production of vector-like quarks, both up-type (T) and down-type (B), as well as for four-top-quark production, is presented. The search is based on pp collisions at (Formula presented.) TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 20.3 fb ⁻¹. Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets. Dedicated analyses are performed targeting three cases: a T quark with significant branching ratio to a W boson and a b-quark (TT¯→Wb+X), and both a T quark and a B quark with significant branching ratio to a Higgs boson and a third-generation quark (TT¯→Ht+XandBB¯→Hb+X respectively). No significant excess of events above the Standard Model expectation is observed, and 95% CL lower limits are derived on the masses of the vector-like T and B quarks under several branching ratio hypotheses assuming contributions from T → Wb, Zt, Ht and B → Wt, Zb, Hb decays. The 95% CL observed lower limits on the T quark mass range between 715 GeV and 950 GeV for all possible values of the branching ratios into the three decay modes, and are the most stringent constraints to date. Additionally, the most restrictive upper bounds on four-top-quark production are set in a number of new physics scenarios. 2018-06-21T18:10:57Z 2018-06-21T18:10:57Z 2015-08 2015-05 2018-06-18T12:02:32Z Article http://purl.org/eprint/type/JournalArticle 1029-8479 http://hdl.handle.net/1721.1/116505 Aad, G., B. Abbott, J. Abdallah, O. Abdinov, R. Aben, M. Abolins, et al. “Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector.” Journal of High Energy Physics 2015, 8 (August 2015): 105 © 2015 The Author(s) https://orcid.org/0000-0002-7586-7253 http://dx.doi.org/10.1007/JHEP08(2015)105 Journal of High Energy Physics Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0/ application/pdf Springer Berlin Heidelberg Springer |
| spellingShingle | ATLAS Collaboration Taylor, Frank E Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector |
| title | Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector |
| title_full | Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector |
| title_fullStr | Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector |
| title_full_unstemmed | Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector |
| title_short | Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector |
| title_sort | search for production of vector like quark pairs and of four top quarks in the lepton plus jets final state in pp collisions at √s 8 tev with the atlas detector |
| url | http://hdl.handle.net/1721.1/116505 https://orcid.org/0000-0002-7586-7253 |
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