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Search for new particles in fnal states with a boosted top quark and missing transverse momentum in proton-proton collisions at √s = 13 TeV with the ATLAS detector

Springer Berlin Heidelberg

A search for events with one top quark and missing transverse momentum in the fnal state is presented. The fully hadronic decay of the top quark is explored by selecting events with a reconstructed boosted top-quark topology produced in association with large missing transverse momentum. The analysis uses 139 fb−1 of proton-proton collision data at a centre-of-mass energy of √ s = 13 TeV recorded during 2015-2018 by the ATLAS detector at the Large Hadron Collider. The results are interpreted in the context of simplifed models for Dark Matter particle production and the single production of a vector-like T quark. Without signifcant excess relative to the Standard Model expectations, 95% confdence-level upper limits on the corresponding cross-sections are obtained. The production of Dark Matter particles in association with a single top quark is excluded for masses of a scalar (vector) mediator up to 4.3 (2.3) TeV, assuming mχ = 1 GeV and the model couplings λq = 0.6 and λχ = 0.4 (a = 0.5 and gχ = 1). The production of a single vector-like T quark is excluded for masses below 1.8 TeV assuming a coupling to the top quark κT = 0.5 and a branching ratio for T → Zt of 25%.

Article

eng

Vancouver : University of British Columbia Library

10.14288/1.0447107

Science, Faculty of; TRIUMF; Non UBC; Physics and Astronomy, Department of

10.1007/JHEP05(2024)263

Faculty

http://creativecommons.org/licenses/by/4.0/