Single-top associated production with a Z or H boson at the LHC: the SMEFT interpretation

Journal of High Energy Physics, Oct 2018

Abstract At the LHC, top quarks can be produced singly with a sizeable rate via electroweak interactions. This process probes a limited set of top-quark electroweak couplings, i.e., the same entering the top-quark decay, yet at higher scales and with a different sensitivity. Requiring the production of a Z or H boson in association with single-top significantly extends the sensitivity of this process to new physics, opening up the unique possibility of testing top-Higgs, top-gauge, triple gauge, gauge-Higgs interactions without being dominated by QCD interactions. We consider tZj and tHj production at the LHC, providing predictions at next-to-leading accuracy in QCD in the framework of the standard model effective field theory, including all relevant operators up to dimension six. We perform the first complete study of the sensitivity to new interactions of these processes, highlighting the interplay and complementarity among tj, tZj and tHj in simultaneously constraining top-quark, triple gauge, and gauge-Higgs interactions in the current and future runs at the LHC.

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Single-top associated production with a Z or H boson at the LHC: the SMEFT interpretation

Journal of High Energy Physics October 2018, 2018:5 | Cite as Single-top associated production with a Z or H boson at the LHC: the SMEFT interpretation AuthorsAuthors and affiliations Celine DegrandeFabio MaltoniKen MimasuEleni VryonidouCen Zhang Open Access Regular Article - Theoretical Physics First Online: 01 October 2018 11 Downloads Abstract At the LHC, top quarks can be produced singly with a sizeable rate via electroweak interactions. This process probes a limited set of top-quark electroweak couplings, i.e., the same entering the top-quark decay, yet at higher scales and with a different sensitivity. Requiring the production of a Z or H boson in association with single-top significantly extends the sensitivity of this process to new physics, opening up the unique possibility of testing top-Higgs, top-gauge, triple gauge, gauge-Higgs interactions without being dominated by QCD interactions. We consider tZj and tHj production at the LHC, providing predictions at next-to-leading accuracy in QCD in the framework of the standard model effective field theory, including all relevant operators up to dimension six. We perform the first complete study of the sensitivity to new interactions of these processes, highlighting the interplay and complementarity among tj, tZj and tHj in simultaneously constraining top-quark, triple gauge, and gauge-Higgs interactions in the current and future runs at the LHC. Keywords NLO Computations Phenomenological Models  ArXiv ePrint: 1804.07773 Download to read the full article text Notes Open Access This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. References [1] S. Weinberg, Phenomenological lagrangians, Physica A 96 (1979) 327 [INSPIRE].ADSCrossRefGoogle Scholar [2] W. 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Celine Degrande, Fabio Maltoni, Ken Mimasu, Eleni Vryonidou, Cen Zhang. Single-top associated production with a Z or H boson at the LHC: the SMEFT interpretation, Journal of High Energy Physics, 2018, 5, DOI: 10.1007/JHEP10(2018)005