Electroweak top couplings, partial compositeness, and top partner searches

We present updated results for a global fit of dimension-six operators in the top quark sector of the Standard Model Effective Field Theory using experimental data from the Tevatron and the LHC at 7, 8 and 13 TeV center-of-mass energy. We include all contributions from dimension-six operators up to and including Λ −4 in the effective field theory expansion. Furthermore we take the top quark decay into account and include in the fit experimental measurements which provide results for observables that depend on the kinematics of the top (anti)quark decay products. This opens up the possibility to study additional operators such as four-fermion operators which couple top quarks directly to leptons. A new strategy for sampling the parameter space of Wilson coefficients and treatment of systematic uncertainties is employed. In this contribution we restrict ourselves to present results in terms of bounds on individual operators.

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“…A first application of the updated T F was presented in Ref. [17] where it was used to obtain constraints on a composite Higgs model.…”

Section: Resultsmentioning

confidence: 99%

New results from TopFitter

Galler¹,

Brown²,

Buckley³

et al. 2021

Proceedings of 40th International Conference on High Energy Physics — PoS(ICHEP2020)

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“…This is the limit where our results are most relevant: BSM degrees of freedom with non-trivial QCD interactions that are integrated out to arrive at C Gφ,S , C Gφ,S = 0 can typically can be more efficiently constrained by direct searches at hadron colliders, see e.g. the recent discussion of [60,61].…”

Section: Loop-induced Higgs Phenomenologymentioning

confidence: 99%

Extended Higgs boson sectors, effective field theory, and Higgs boson phenomenology

et al. 2021

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We consider the phenomenological implications of charged scalar extensions of the SM Higgs sector in addition to EFT couplings of this new state to SM matter. We perform a detailed investigation of modifications of loop-induced decays of the 125 GeV Higgs boson, which receives corrections from the propagating charged scalars alongside one-loop EFT operator insertions and demonstrate that the interplay of H → γγ and H → Zγ decays can be used to clarify the additional states phenomenology in case a discovery is made in the future. In parallel, EFT interactions of the charged Higgs can lead to a decreased sensitivity to the virtual presence of charged Higgs states, which can significantly weaken the constraints that are naively expected from the precisely measured H → γγ branching ratio. Again H → Zγ measurements provide complementary sensitivity that can be exploited in the future.

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“…This can result in very tight constraints on the parameters of the UV model due to the correlations between the Wilson coefficients that are induced by that model (for a recent example, see Ref. [9]). Hence, the machinery and power of global EFT fits can also be applied to obtain valuable information about plausible UV completions and their parameter spaces.…”

Section: Pos(lhcp2020)181mentioning

confidence: 99%