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Many studies of possible new physics employ effective field theory (EFT), whereby corrections to the Standard Model take the form of higher-dimensional operators, suppressed by a large energy scale. Fits of such a theory to data typically use parton level observables, which limits the datasets one can use. In order to theoretically model search channels involving many additional jets, it is important to include tree-level matrix elements matched to a parton shower algorithm, and a suitable matching procedure to remove the double counting of additional radiation. There are then two potential problems: (i) EFT corrections are absent in the shower, leading to an extra source of discontinuities in the matching procedure; (ii) the uncertainty in the matching procedure may be such that no additional constraints are obtained from observables sensitive to radiation. In this paper, we review why the first of these is not a problem in practice, and perform a detailed study of the second. In particular, we quantify the additional constraints on EFT expected from top pair plus multijet events, relative to inclusive top pair production alone.
Effective field theory (EFT) approaches are widely used at the LHC, such that it is important to study their validity, and ease of matching to specific new physics models. In this paper, we consider an extension of the SM in which a top quark couples
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
We examine the constraints that future lepton colliders would impose on the effective field theory describing modifications of top-quark interactions beyond the standard model, through measurements of the $e^+e^-to bW^+:bar bW^-$ process. Statistical
We address the issue of a consistent power counting scheme in manifestly Lorentz-invariant baryon chiral perturbation theory. We discuss the inclusion of vector mesons in the calculation of the nucleon electromagnetic form factors. We comment on the
We study the sensitivity to physics beyond the standard model of precise top-quark pair production measurements at future lepton colliders. A global effective-field-theory approach is employed, including all dimension-six operators of the Warsaw basi