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In a recent paper we showed that the electroweak chiral Lagrangian at leading order is equivalent to the conventional κ formalism used by ATLAS and CMS to test Higgs anomalous couplings. Here we apply this fact to fit the latest Higgs data. The new aspect of our analysis is a systematic interpretation of the fit parameters within an EFT. Concentrating on the processes of Higgs production and decay that have been measured so far, six parameters turn out to be relevant: c V , c t , c b , c τ , c γ γ , c g g . A global Bayesian fit is then performed with the result c V = 0.98 ± 0.09 , c t = 1.34 ± 0.19 , c b = 0.78 ± 0.18 , c τ = 0.92 ± 0.14 , c γ γ = - 0.24 ± 0.37 , c g g = - 0.30 ± 0.17 . Additionally, we show how this leading-order parametrization can be generalized to next-to-leading order, thus improving the κ formalism systematically. The differences with a linear EFT analysis including operators of dimension six are also discussed. One of the main conclusions of our analysis is that since the conventional κ formalism can be properly justified within a QFT framework, it should continue to play a central role in analyzing and interpreting Higgs data.

The integrated branching fraction of the process B → X s l + l − is dominated by resonance background from narrow charmonium states, such as B → X s ψ → X s l + l − , which exceeds the non-resonant charm-loop contribution by two orders of magnitude. The origin of this fact is discussed in view of the general expectation of quark–hadron duality. The situation in B → X s l + l − is contrasted with charm-penguin amplitudes in two-body hadronic B decays of the type B → π π , for which it is demonstrated that resonance effects and the potentially non-perturbative threshold region do not invalidate the standard picture of QCD factorization. This holds irrespective of whether the charm quark is treated as a light or a heavy quark.

A bstract We present a calculation of the NLO QCD corrections to Higgs boson pair production within the framework of a non-linearly realised Effective Field Theory in the Higgs sector, described by the electroweak chiral Lagrangian. We analyse how the NLO corrections affect distributions in the Higgs boson pair invariant mass and the transverse momentum of one of the Higgs bosons. We find that these corrections lead to significant and non-homogeneous K-factors in certain regions of the parameter space. We also provide an analytical parametrisation for the total cross-section and the m hh distribution as a function of the anomalous Higgs couplings that includes NLO corrections. Such a parametrisation can be useful for phenomenological studies.

We analyze new-physics contributions to [e.sup.+][e.sup.-] [right arrow] [W.sup.+] [W.sup.-] at the TeV energy scale, employing an effective field theory framework. A complete basis of next-to-leading-order operators in the standard-model effective Lagrangian is used, both for the nonlinear and the linear realization of the electroweak sector. The elimination of redundant operators via equations-of-motion constraints is discussed in detail. Polarized cross sections for [e.sup.+][e.sup.-] → [W.sup.+] [W.sup.-] (on-shell) are computed and the corrections to the standard-model results are given in an expansion for large s/[M.sup.2.sub.W]. The dominant relative corrections grow with s and can be fully expressed in terms of modified gauge-fermion couplings. These corrections are interpreted in the context of the Goldstone-boson equivalence theorem. Explicit new-physics models are considered to illustrate the generation and the potential size of the coefficients in the effective Lagrangian. Brief comments are made on the production of [W.sup.+] [W.sup.-] pairs at the LHC.

We develop a systematic framework for exclusive rare B decays of the type B → K (∗) l + l − at large dilepton invariant mass q 2 . It is based on an operator product expansion (OPE) for the required matrix elements of the nonleptonic weak Hamiltonian in this kinematic regime. Our treatment differs from previous work by a simplified operator basis, the explicit calculation of matrix elements of subleading operators, and by a quantitative estimate of duality violation. The latter point is discussed in detail, including the connection with the existence of an OPE and an illustration within a simple toy model.

We present a calculation of the NLO QCD corrections to Higgs boson pair production within the framework of a non-linearly realised Effective Field Theory in the Higgs sector, described by the electroweak chiral Lagrangian. We analyse how the NLO corrections affect distributions in the Higgs boson pair invariant mass and the transverse momentum of one of the Higgs bosons. We find that these corrections lead to significant and non-homogeneous K-factors in certain regions of the parameter space. We also provide an analytical parametrisation for the total cross-section and the mhh distribution as a function of the anomalous Higgs couplings that includes NLO corrections. Such a parametrisation can be useful for phenomenological studies.

We develop a systematic framework for exclusive rare B decays of the type B → [K.sup.(*)][l.sup.+][l.sup.-] at large dilepton invariant mass [q.sup.2]. It is based on an operator product expansion (OPE) for the required matrix elements of the nonleptonic weak Hamiltonian in this kinematic regime. Our treatment differs from previous work by a simplified operator basis, the explicit calculation of matrix elements of subleading operators, and by a quantitative estimate of duality violation. The latter point is discussed in detail, including the connection with the existence of an OPE and an illustration within a simple toy model.

We develop a systematic framework for exclusive rare B decays of the type B→K(∗)l+l− at large dilepton invariant mass q2. It is based on an operator product expansion (OPE) for the required matrix elements of the nonleptonic weak Hamiltonian in this kinematic regime. Our treatment differs from previous work by a simplified operator basis, the explicit calculation of matrix elements of subleading operators, and by a quantitative estimate of duality violation. The latter point is discussed in detail, including the connection with the existence of an OPE and an illustration within a simple toy model.