A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector

Nathan P. Hartland, Fabio Maltoni, Emanuele R. Nocera, Juan Rojo, Emma Slade, Eleni Vryonidou, Cen Zhang*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

137 Downloads (Pure)


We present a novel framework for carrying out global analyses of the Standard Model Effective Field Theory (SMEFT) at dimension-six: SMEFiT. This approach is based on the Monte Carlo replica method for deriving a faithful estimate of the experimental and theoretical uncertainties and enables one to construct the probability distribution in the space of the SMEFT degrees of freedom. As a proof of concept of the SMEFiT methodology, we present a first study of the constraints on the SMEFT provided by top quark production measurements from the LHC. Our analysis includes more than 30 independent measurements from 10 different processes at s = 8 and 13 TeV such as inclusive tt¯ and single-top production and the associated production of top quarks with weak vector bosons and the Higgs boson. State-of-the-art theoretical calculations are adopted both for the Standard Model and for the SMEFT contributions, where in the latter case NLO QCD corrections are included for the majority of processes. We derive bounds for the 34 degrees of freedom relevant for the interpretation of the LHC top quark data and compare these bounds with previously reported constraints. Our study illustrates the significant potential of LHC precision measurements to constrain physics beyond the Standard Model in a model-independent way, and paves the way towards a global analysis of the SMEFT.

Original languageEnglish
Article number100
Pages (from-to)1-78
Number of pages78
JournalJournal of High Energy Physics
Issue number4
Early online date15 Apr 2019
Publication statusPublished - Apr 2019


the supercomputing facilities of the Universitécatholique de Louvain (CISM/UCL) and the Consortium des Équipements de Calcul Intensif en Fédération Wallonie Bruxelles (CÉCI). N.H., J.R., and E.S. are supported by the European Research Council Starting Grant “PDF4BSM”. J.R. is also partially supported by the Netherlands Organization for Scientific Research (NWO). E.R.N. is supported by the European Commission through the Marie Sklo dowska-Curie Action ParDHonS FFs.TMDs (grant number 752748), and was supported by the UK Science and Technology Facility Council through grant ST/P000630/1. E.V. is supported by a Marie Sklodowska-Curie Individual Fellowship of the European Commission’s Horizon 2020 Programme under contract number 704187. C.Z. is supported by IHEP under Contract No. Y7515540U1. J.R. would like to thank Gerhard Raven and Wouter Verkerke for illuminating discussions. F.M. has received fundings from the European Union’s Horizon 2020 research and innovation programme as part of the Marie Sklodowska-Curie Innovative Training Network MCnetITN3 (grant agreement no. 722104) and by the F.R.S.-FNRS under the ‘Excellence of Science‘ EOS be.h project n. 30820817. Computational resources have been provided by

FundersFunder number
Marie Sklo dowska-Curie Action ParDHonS FFs.TMDs
Netherlands Organization for Scientific Research
UK Science and Technology Facility CouncilST/P000630/1
Horizon 2020 Framework Programme752748
European Commission
European Research Council
Nederlandse Organisatie voor Wetenschappelijk Onderzoek
Horizon 2020704187, 722104
Institute of High Energy Physics


    • Beyond Standard Model
    • Effective Field Theories
    • Perturbative QCD


    Dive into the research topics of 'A Monte Carlo global analysis of the Standard Model Effective Field Theory: the top quark sector'. Together they form a unique fingerprint.

    Cite this