A Monte Carlo analysis of the SMEFT in the top quark sector

Apr 9, 2019, 5:05 PM
Palazzo Badini-Confalonieri - Sala Seminari

Palazzo Badini-Confalonieri - Sala Seminari

Via Verdi, 10 Turin
Parallel Session Talk WG3: Higgs and BSM Physics in Hadron Collisions WG3: Higgs and BSM Physics in Hadron Collisions


Emma Slade (University of Oxford)


We present a novel framework to carry out global analyses of the Standard Model Effective Field Theory (SMEFT) at dimension-six: SMEFiT. The SMEFiT approach is based on the Monte Carlo replica method to derive 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 an extensive 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 $\sqrt{s}=8$ and 13 TeV, including inclusive $t\bar{t}$ and single-top production and the associated production of top quarks with vector bosons and the Higgs boson.

State-of-the-art theoretical calculations are adopted both for the SM and 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 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 pave the way towards a global analysis of the SMEFT.

Primary author

Emma Slade (University of Oxford)

Presentation materials