Aad, G;
Abbott, B;
Abbott, DC;
Abud, AA;
Abeling, K;
Abhayasinghe, DK;
Abidi, SH;
... et al, .; + view all
(2020)
Search for a scalar partner of the top quark in the all-hadronic t\bar{t} plus missing transverse momentum final state at \sqrt{s} =13 TeV with the ATLAS detector.
European Physical Journal C
, 80
(8)
, Article 737. 10.1140/epjc/s10052-020-8102-8.
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Abstract
A search for direct pair production of scalar partners of the top quark (top squarks or scalar third-generation up-type leptoquarks) in the all-hadronic t\bar{t} plus missing transverse momentum final state is presented. The analysis of 139 fb^{-1} \sqrt{s} = 13 TeV proton–proton collision data collected using the ATLAS detector at the LHC yields no significant excess over the Standard Model background expectation. To interpret the results, a supersymmetric model is used where the top squark decays via \tilde{t} \rightarrow t^{(*)} \tilde{x}\frac{0}{1}, with t^{(*)} denoting an on-shell (off-shell) top quark and \tilde{x}\frac{0}{1} the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where m_{tilde{t}} > m_{t} + m_{\tilde{x}\frac{0}{1}}, top squark masses are excluded in the range 400–1250 GeV for \tilde{x}\frac{0}{1} masses below 200 GeV at 95% confidence level. In the situation where m_{tilde{t}} \sim m_{t} + M_{\tilde{x}\frac{0}{1}}, top squark masses in the range 300–630 GeV are excluded, while in the case where m_{tilde{t}} < m_{W} + m_{b} + m_{\tilde{x}\frac{0}{1}} (with m_{tilde{t}}) \geq 5 GeV), considered for the first time in an ATLAS all-hadronic search, top squark masses in the range 300–660 GeV are excluded. Limits are also set for scalar third-generation up-type leptoquarks, excluding leptoquarks with masses below 1240 GeV when considering only leptoquark decays into a top quark and a neutrino.
| Type: | Article |
|---|---|
| Title: | Search for a scalar partner of the top quark in the all-hadronic t\bar{t} plus missing transverse momentum final state at \sqrt{s} =13 TeV with the ATLAS detector |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1140/epjc/s10052-020-8102-8 |
| Publisher version: | https://doi.org/10.1140/epjc/s10052-020-8102-8 |
| Language: | English |
| Additional information: | © 2020 Springer Nature Switzerland AG. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/). |
| 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/10109137 |
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