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Related papers: Software tools for computing EW chiral amplitudes

200 papers

We formulate the equivalence theorem as a theoretical criterion for sensitively probing the electroweak symmetry breaking mechanism, and develop a precise power counting method for the chiral Lagrangian formulated electroweak theories.…

High Energy Physics - Phenomenology · Physics 2009-10-28 H. -J. He , Y. -P. Kuang , C. -P. Yuan

The Higgs discovery and the lack of any other hint for new physics favor a description of non-standard Higgs physics in terms of an effective field theory. We present an implementation of a general Higgs effective Lagrangian containing…

High Energy Physics - Phenomenology · Physics 2014-04-29 Adam Alloul , Benjamin Fuks , Veronica Sanz

The loop expansion is applied to a chiral effective hadronic lagrangian; with the techniques of Infrared Regularization, it is possible to separate out the short-range contributions and to write them as local products of fields that are…

Nuclear Theory · Physics 2008-11-26 Jeff McIntire , Ying Hu , Brian D. Serot

We describe a framework to develop, implement and validate any perturbative Lagrangian-based particle physics model for further theoretical, phenomenological and experimental studies. The starting point is FeynRules, a Mathematica package…

High Energy Physics - Phenomenology · Physics 2011-02-11 Neil D. Christensen , Priscila de Aquino , Celine Degrande , Claude Duhr , Benjamin Fuks , Michel Herquet , Fabio Maltoni , Steffen Schumann

A revised and complete list of the electroweak chiral lagrangian operators up to dimension-four is provided. The connection of these operators to the $S$, $T$ and $U$ parameters and the parameters describing the triple gauge boson vertices…

High Energy Physics - Phenomenology · Physics 2009-10-22 T. Appelquist , G. Wu

We consider the general chiral effective action which parametrizes the nonlinear realization of the spontaneous breaking of the electroweak symmetry with a light Higgs, and compute the one-loop ultraviolet divergences coming from Higgs and…

High Energy Physics - Phenomenology · Physics 2015-10-14 Feng-Kun Guo , Pedro Ruiz-Femenia , Juan Jose Sanz-Cillero

Using a chiral Lagrangian we show that strongly interacting models of electroweak symmetry breaking are not in conflict with precision data. Such models, like Technicolor, need not lead to a heavy Higgs-like signal. Furthermore, the allowed…

High Energy Physics - Phenomenology · Physics 2017-08-23 Andreas Nyffeler

The formalism of the matching conditions between transverse connected Green functions is extended to include the two next to leading corrections, namely the two-loop $M_{H}^{2}$ and the one-loop $1/M_{H}^{2}$ contributions to the…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Matias

The effective Lagrangian of QED coupled to dyons is calculated. The resulting generalization of the Euler-Heisenberg Lagrangian contains non-linear $P$- and $T$-nonivariant (but $C$ invariant) terms corresponding to the virtual pair…

High Energy Physics - Theory · Physics 2007-05-23 V. G. Kovalevich , P. Osland , Ya. M. Shnir , E. A. Tolkachev

We integrate out the Higgs boson in the electroweak standard model at one loop and construct a low-energy effective Lagrangian assuming that the Higgs mass is much larger than the gauge-boson masses. Instead of applying diagrammatical…

High Energy Physics - Phenomenology · Physics 2009-10-28 Stefan Dittmaier , Carsten Grosse-Knetter

We consider the scalar sector of the effective non-linear electroweak Lagrangian with a light "Higgs" particle, up to four derivatives in the chiral expansion. The complete off-shell renormalization procedure is implemented, including one…

High Energy Physics - Phenomenology · Physics 2015-06-22 M. B. Gavela , K. Kanshin , P. A. N. Machado , S. Saa

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 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 study both the CP-even and CP-odd effective chiral Lagrangians of next minimal composite Higgs model {with symmetry breaking pattern depicted by the coset $SO(6)/SO(5)$} through the sigma/omega decomposition, in which the Goldstone…

High Energy Physics - Phenomenology · Physics 2021-01-20 Yong-Hui Qi , Jiang-Hao Yu , Shou-Hua Zhu

We present eHDECAY, a modified version of the program HDECAY which includes the full list of leading bosonic operators of the Higgs effective Lagrangian with a linear or non-linear realization of the electroweak symmetry and implements two…

High Energy Physics - Phenomenology · Physics 2015-06-19 Roberto Contino , Margherita Ghezzi , Christophe Grojean , Margarete Muhlleitner , Michael Spira

Beyond standard model (BSM) particles should be included in effective field theory in order to compute the scattering amplitudes involving these extra particles. We formulate an extension of Higgs effective field theory which contains…

High Energy Physics - Phenomenology · Physics 2021-07-07 Ryo Nagai , Masaharu Tanabashi , Koji Tsumura , Yoshiki Uchida

The couplings of the electroweak effective theory contain information on the heavy-mass scales which are no-longer present in the low-energy Lagrangian. We build a general effective Lagrangian, implementing the electroweak chiral symmetry…

High Energy Physics - Phenomenology · Physics 2017-07-24 Antonio Pich , Ignasi Rosell , Joaquin Santos , Juan Jose Sanz-Cillero

The evaluation of quantum corrections in the theory of the electroweak and strong interactions via higher-order Feynman diagrams requires complicated and laborious calculations, which however can be structured in a strictly algorithmic way.…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. Weiglein

We integrate out the Higgs boson in the electroweak standard model at one loop, assuming that it is very heavy. We construct a low-energy effective Lagrangian, which parametrizes the one-loop effects of the heavy Higgs boson at O(M_H^0).…

High Energy Physics - Phenomenology · Physics 2009-10-28 Stefan Dittmaier , Carsten Grosse-Knetter

Parameters of the effective chiral lagrangian (EChL) of orders $O(p^4)$ and $O(p^6)$ are extracted from low--energy behaviour of dual resonance models for $ \pi\pi$ and $\pi K$ scattering amplitudes. Dual resonance models are considered to…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. V. Polyakov , V. V. Vereshagin