Butterworth, Jonathan;
ATLAS Collaboration;
(2023)
Search for pair-production of vector-like quarks in pp collision events
at √s = 13 TeV with at least one leptonically decaying Z boson and a
third-generation quark with the ATLAS detector.
Physics Letters B: Nuclear Physics and Particle Physics
, 843
, Article 138019. 10.1016/j.physletb.2023.138019.
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Abstract
A search for the pair-production of vector-like quarks optimized for decays into a Z boson and a third-generation Standard Model quark is presented, using the full Run 2 dataset corresponding to 139 fb−1 of pp collisions at √s = 13 TeV, collected in 2015–2018 with the ATLAS detector at the Large Hadron Collider. The targeted final state is characterized by the presence of a Z boson with high transverse momentum, reconstructed from a pair of same-flavour leptons with opposite-sign charges, as well as by the presence of b-tagged jets and high-transverse-momentum large-radius jets reconstructed from calibrated smaller-radius jets. Events with exactly two or at least three leptons are used, which are further categorized by the presence of boosted W , Z, and Higgs bosons and top quarks. The categorization is performed using a neural-network-based boosted object tagger to enhance the sensitivity to signal relative to the background. No significant excess above the background expectation is observed and exclusion limits at 95% confidence level are set on the masses of the vector-like partners T and B of the top and bottom quarks, respectively. The limits depend on the branching ratio configurations and, in the case of 100% branching ratio for T → Z t and 100% branching ratio for B → Zb, this search sets the most stringent limits to date, allowing mT > 1.60 TeV and mB > 1.42 TeV, respectively.
| Type: | Article |
|---|---|
| Title: | Search for pair-production of vector-like quarks in pp collision events at √s = 13 TeV with at least one leptonically decaying Z boson and a third-generation quark with the ATLAS detector |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.physletb.2023.138019 |
| Publisher version: | https://doi.org/10.1016/j.physletb.2023.138019 |
| Language: | English |
| Additional information: | © 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10173442 |
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