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Related papers: Constraints on the electroweak chiral Lagrangian f…

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We consider the Standard Model, including a light scalar boson $h$, as an effective theory at the weak scale $v=246\,{\rm GeV}$ of some unknown dynamics of electroweak symmetry breaking. This dynamics may be strong, with $h$ emerging as a…

High Energy Physics - Phenomenology · Physics 2015-12-08 Gerhard Buchalla , Oscar Cata , Claudius Krause

We refine our recent analysis of the electroweak precision data at the \PZO\ pole by including the hadronic decay modes of the \PZO. Within the framework of an effective Lagrangian we parametrize $SU(2)$ violation by the additional…

High Energy Physics - Phenomenology · Physics 2010-11-01 S. Dittmaier , M. Kuroda , D. Schildknecht

We propose to probe the electroweak symmetry breaking sector by measuring the effective couplings of the top quark to gauge bosons. Using precision LEP data, we constrain the non--universal couplings of t-t-Z and t-b-W, parameterized by…

High Energy Physics - Phenomenology · Physics 2010-11-01 Ehab Malkawi , C. --P Yuan

We elaborate on a recently suggested effective Lagrangian for charged-current and neutral-current electroweak interactions which in comparison with the standard electroweak theory contains three free parameters $\Delta x, \Delta y$,…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Dittmaier , D. Schildknecht , K. Kolodziej , M. Kuroda

The compact form of the electroweak chiral Lagrangian is a reformulation of its original form and is expressed in terms of chiral rotated electroweak gauge fields, which is crucial for relating the information of underlying theories to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hong-Hao Zhang , Wen-Bin Yan , J. K. Parry , Xue-Song Li

We review the empirical evidence for the validity of the Standard Electroweak Theory in Nature. The experimental data are interpreted in terms of an effective Lagrangian for Z physics, allowing for potential sources of SU(2) violation and…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Schildknecht

We report a high-precision calculation of the Standard Model electroweak radiative corrections in the $K\to \pi e^+\nu(\gamma)$ decay as a part of the combined theory effort to understand the existing anomaly in the determinations of…

High Energy Physics - Phenomenology · Physics 2021-08-11 Chien-Yeah Seng , Daniel Galviz , Mikhail Gorchtein , Ulf-G. Meißner

We report on a novel scheme based on the chiral Lagrangian. It is used to analyze pion-nucleon scattering, pion photoproduction, and nucleon Compton scattering. Subthreshold partial-wave amplitudes are calculated in chiral perturbation…

High Energy Physics - Phenomenology · Physics 2015-05-20 A. M. Gasparyan , M. F. M. Lutz

We present an effective Lagrangian parameterization describing scalar, vector, and axial-vector bound states, originating from a strong breaking of the electroweak symmetry, based on the global symmetry $SU(N)_L\otimes SU(N)_R$. In this…

High Energy Physics - Phenomenology · Physics 2015-05-18 R. Casalbuoni , A. Deandrea , S. De Curtis , N. Di Bartolomeo , D. Dominici , F. Feruglio , R. Gatto

We study the complete non-decoupling effects of the standard model Higgs boson to one loop. Using effective field theory methods, we integrate out the Higgs boson and represent its non-decoupling effects by a set of gauge invariant…

High Energy Physics - Phenomenology · Physics 2009-10-28 Maria J. Herrero , Ester Ruiz Morales

We study large top quark mass effects on low energy physics in the chiral Lagrangian formulated electroweak theories. We show that these radiative corrections can be easily obtained from a set of Feynman diagrams involving only the scalar…

High Energy Physics - Phenomenology · Physics 2009-10-28 Ehab Malkawi , C. --P. Yuan

We present a one-loop calculation of the oblique S and T parameters within strongly-coupled models of electroweak symmetry breaking with a light Higgs-like boson. We use a general effective Lagrangian, implementing the chiral symmetry…

High Energy Physics - Phenomenology · Physics 2013-05-17 Ignasi Rosell

We study the renormalization of the nonlinear effective U(1) Lagrangian up to $O(p^4)$ with spontaneous symmetry breaking. The problems of the quartic divergences and of the truncation of infinite divergence tower are addressed. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 Qi-Shu Yan , Dong-Sheng Du

Based on previous studies deriving the chiral Lagrangian for pseudo scalar mesons from the first principle of QCD, we derive the electroweak chiral Lagrangian and build up a formulation for computing its coefficients from one-doublet…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hong-Hao Zhang , Shao-Zhou Jiang , Qing Wang

We calculate the oblique electroweak corrections and confront with the experiments in an extension of the Standard Model. The new fields added are a vector-like weak doublet and a singlet fermion. After electroweak symmetry breaking there…

High Energy Physics - Phenomenology · Physics 2008-12-18 G. Cynolter , E. Lendvai

The recent precision electroweak data on $\Gamma^l, \bar s^2_W$ and $M_W/M_Z$ are compared with the tree-level and the dominant-fermion-loop as well as the full one-loop standard-model predictions. While the tree-level predictions are ruled…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Bilenky , K. Kolodziej , M. Kuroda , D. Schildknecht

Electroweak measurements place significant bounds on higher-dimensional versions of the standard model in which the gauge and Higgs fields have Kaluza-Klein excitations. These bounds may be altered quantitatively if chiral matter is also…

High Energy Physics - Phenomenology · Physics 2009-10-31 Christopher D. Carone

Extensions of the Standard Model which involve a new scale, $\Lambda$, may, for energies sufficiently small compared to this new scale, be expressed in terms of operators with energy dimension greater than four. The coefficients of just…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Hagiwara , S. Matsumoto , R. Szalapski

This work presents a first full one-loop computation of vector boson scattering (VBS) within the non-linear effective field theory given by the bosonic sector of the usually called electroweak chiral Lagrangian (EChL). The computation is…

High Energy Physics - Phenomenology · Physics 2021-10-22 Maria J. Herrero , Roberto A. Morales

We consider the Standard Model as an effective theory at the weak scale $v$ of a generic new strong interaction that dynamically breaks electroweak symmetry at the energy scale $\Lambda\sim $ (few) TeV. Assuming only the minimal field…

High Energy Physics - Phenomenology · Physics 2015-06-04 Gerhard Buchalla , Oscar Cata