English
Related papers

Related papers: Electroweak chiral Lagrangian with a light Higgs

200 papers

We perform a Bayesian statistical analysis of the constraints on the nonlinear Effective Theory given by the Higgs electroweak chiral Lagrangian. We obtain bounds on the effective coefficients entering in Higgs observables at the leading…

High Energy Physics - Phenomenology · Physics 2018-07-17 Jorge de Blas , Otto Eberhardt , Claudius Krause

Effective Lagrangians represent an important, model independent tool for studying physics beyond the Standard Model, via its impact on electroweak scale observables. In particular, two different effective descriptions may be appropriate,…

High Energy Physics - Phenomenology · Physics 2015-05-19 Ilaria Brivio

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

In the light of the mass gap between Standard Model (SM) states and possible new particles, effective field theories are a suitable approach. We take on the non-linear realization of the electroweak symmetry breaking: the electroweak…

High Energy Physics - Phenomenology · Physics 2020-10-19 Ignasi Rosell , Antonio Pich , Juan José Sanz-Cillero

These lectures provide an introduction to the low-energy dynamics of Nambu-Goldstone fields, associated with some spontaneous (or dynamical) symmetry breaking, using the powerful methods of effective field theory. The generic symmetry…

High Energy Physics - Phenomenology · Physics 2020-01-28 Antonio Pich

The most general chiral Lagrangian for electroweak interactions with the complete set of $SU(2)_L\times U(1)_Y$ invariant operators up to dimension four is considered. The two-point and three-point functions with external gauge fields are…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. J. Herrero , E. Ruiz Morales

The electroweak sector of the Standard Model can be formulated in a way similar to Chiral Perturbation Theory (ChPT), but extended by a singlet scalar. The resulting effective field theory (EFT) is called Higgs-Electroweak Chiral Lagrangian…

High Energy Physics - Phenomenology · Physics 2019-07-18 Claudius Krause , Gerhard Buchalla , Oscar Catà , Alejandro Celis , Marc Knecht

We generalize the basis of CP-even chiral effective operators describing a dynamical Higgs sector, to the case in which the Higgs-like particle is light. Gauge and gauge-Higgs operators are considered up to mass dimension five. This…

High Energy Physics - Phenomenology · Physics 2015-06-12 R. Alonso , M. B. Gavela , L. Merlo , S. Rigolin , J. Yepes

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

In these proceedings we discuss our recent work on $\gamma\gamma\to W^+_L W^-_L$ and $\gamma\gamma\to Z_L Z_L$ within the framework of Electroweak Chiral Lagrangians with a light Higgs. These observables are good candidates to provide…

High Energy Physics - Phenomenology · Physics 2014-09-16 R. L. Delgado , A. Dobado , M. J. Herrero , J. J. Sanz-Cillero

We propose a parametrization of anomalous Higgs-boson couplings that is both systematic and practical. It is based on the electroweak chiral Lagrangian, including a light Higgs boson, as the effective field theory (EFT) at the electroweak…

High Energy Physics - Phenomenology · Physics 2015-09-30 G. Buchalla , O. Cata , A. Celis , C. Krause

We compute the one-loop matching between the Standard Model Effective Field Theory and the low-energy effective field theory below the electroweak scale, where the heavy gauge bosons, the Higgs particle, and the top quark are integrated…

High Energy Physics - Phenomenology · Physics 2022-11-21 Wouter Dekens , Peter Stoffer

The LHC has confirmed the existence of a mass gap between the known particles and possible new states. Effective field theory is then the appropriate tool to search for low-energy signals of physics beyond the Standard Model. We adopt the…

High Energy Physics - Phenomenology · Physics 2020-09-07 Antonio Pich , Ignasi Rosell , Juan José Sanz-Cillero

In composite Higgs models the Higgs is a pseudo-Goldstone boson of a high-energy strong dynamics. We have constructed the effective chiral Lagrangian for a generic symmetric coset, restricting to CP-even bosonic operators up to four momenta…

High Energy Physics - Phenomenology · Physics 2014-12-16 Rodrigo Alonso , Ilaria Brivio , Belen Gavela , Luca Merlo , Stefano Rigolin

We reconsider the effective Lagrangian that describes a light Higgs-like boson and better clarify a few issues which were not exhaustively addressed in the previous literature. In particular we highlight the strategy to determine whether…

High Energy Physics - Phenomenology · Physics 2014-03-14 Roberto Contino , Margherita Ghezzi , Christophe Grojean , Margarete Muhlleitner , Michael Spira

We present a model of electroweak symmetry breaking in which the Higgs boson is a pseudo-Nambu-Goldstone boson. By embedding the standard model SU(2) x U(1) into an SU(4) x U(1) gauge group, one-loop quadratic divergences to the Higgs mass…

High Energy Physics - Phenomenology · Physics 2009-11-10 David E. Kaplan , Martin Schmaltz

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 Dieter Schildknecht

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

In many strongly-interacting models of electroweak symmetry breaking the lowest-lying observable particle is a pseudo-Goldstone boson of approximate scale symmetry, the pseudo-dilaton. Its interactions with Standard Model particles can be…

High Energy Physics - Phenomenology · Physics 2015-06-03 Bruce A. Campbell , John Ellis , Keith A. Olive

In this paper we reanalyze the electroweak chiral Lagrangian with particular focus on two issues related to gauge invariance. Our analysis is based on a manifestly gauge-invariant approach that we introduced recently. It deals with…

High Energy Physics - Phenomenology · Physics 2009-10-31 Andreas Nyffeler , Andreas Schenk