Global fit of top quark effective theory to data

Abstract

In this paper we present a global fit of beyond the Standard Model (BSM) dimension six operators relevant to the top quark sector to all currently available top production cross-section measurements, namely parton-level top-pair and single top production at the LHC and the Tevatron. Higher order QCD corrections are modelled using differential and global K-factors, and we use novel fast-fitting techniques developed in the context of Monte Carlo event generator tuning to perform the fit. This allows us to provide new, fully correlated and model-independent bounds on new physics effects in the top sector from the most current direct hadron-collider measurements in light of the involved theoretical and experimental systematics. As a by-product, our analysis constitutes a proof-of-principle that fast fitting of theory to data is possible in the top quark sector, and paves the way for a more detailed analysis including top quark decays, detector corrections and precision observables.

Probing top quark neutral couplings in the Standard Model Effective Field Theory at NLO in QCD

“…The presented bounds here are marginalised over the S and T parameters, with all other operator coefficients assumed to vanish. We note here that comparable limits have been set on these operators by the recent collider based global analyses of [11,12]. Furthermore, RG-induced limits can also be found in [30].…”

Renormalization group constraints on new top interactions from electroweak precision data

“…[64] appeared in the arXiv. In that work, a global fit to dimension-six effective operators involving the top quark is performed using top production data from the LHC and the Tevatron.…”

Top quark electroweak couplings at future lepton colliders

“…Refs. [6][7][8][9][10][11][12] for a representative sample as well as [13] for a discussion of electroweak precision effects), and a similar effort is well under way in Higgs physics, where the associated limits on Wilson coefficients are typically statistics limited. Still, despite the impressive statistical sample of top quark data that enters these fits, the subsequent direct bounds on the operator coefficients, and, by extension, the scale of new physics that would generate those operators, are rather weak [7].…”