English
Related papers

Related papers: S and T Parameters in the Fermion Condensate Model

200 papers

We calculate renormalized Higgs boson couplings with gauge bosons and fermions at the one-loop level in the model with an additional isospin singlet real scalar field. These coupling constants can deviate from the predictions in the…

High Energy Physics - Phenomenology · Physics 2016-05-04 Shinya Kanemura , Mariko Kikuchi , Kei Yagyu

We calculate both the cubic and the quartic self-couplings of the lighter scalar Higgs boson without assuming the decoupling limit in the two-Higgs-doublet model (THDM). In some regions of parameter space of the THDM where the electroweak…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. W. Ham , S. K. Oh

Using a general (non-linear) effective field theory description of the Standard Model electroweak symmetry breaking, we analyse the impact on the electroweak oblique parameters of hypothetical heavy resonance states strongly coupled to the…

High Energy Physics - Phenomenology · Physics 2025-03-11 Antonio Pich , Ignasi Rosell , Juan José Sanz-Cillero

Within the framework of a general non-linear effective field theory describing the electroweak symmetry breaking, we perform a detailed analysis of the next-to-leading contributions to the electroweak oblique parameters $S$ and $T$ from…

High Energy Physics - Phenomenology · Physics 2025-09-17 Ignasi Rosell , Antonio Pich , Juan Jose Sanz-Cillero

Standard-model fields and their associated electroweak Lagrangian are equivalently expressed in a shared spin basis. The scalar-vector terms are written with scalar-operator components acting on quark-doublet elements, and shown to be…

High Energy Physics - Phenomenology · Physics 2019-04-10 J. Besprosvany , R. Romero

New strong gauge interactions remain a viable source for the electroweak symmetry breaking. However, addressing the generation of fermion masses remains a challenge. A basic observable which provides stringent constraints on the flavor…

High Energy Physics - Phenomenology · Physics 2012-11-22 Hidenori S. Fukano , Kimmo Tuominen

We demonstrate that the electroweak baryogenesis can be realized in the extended Standard Model with sequential fourth generation fermions (SM4). The solution to the coupled Dyson-Schwinger equations for the fermion and Higgs masses…

High Energy Physics - Phenomenology · Physics 2025-09-04 Hsiang-nan Li

We show that an effective field theory that includes non-standard couplings between the electroweak gauge bosons and the top and bottom quarks may yield negative contributions to both the S and T oblique radiative electroweak parameters. We…

High Energy Physics - Phenomenology · Physics 2009-10-30 Bogdan A. Dobrescu , John Terning

In a recent paper, we introduced a new Little Higgs model, which contains the gauge structure $SU(2)^3\times U(1)$, embedded in an approximate global $SO(5)\times SO(5)$ symmetry. After breaking to the standard model, $SU(2)_L \times…

High Energy Physics - Phenomenology · Physics 2013-05-30 Roshan Foadi , Carl R. Schmidt , Jiang-Hao Yu

Two paradigms for the origin of electroweak superconductivity are a weakly coupled scalar condensate, and a strongly coupled fermion condensate. The former suffers from a finetuning problem unless there are cancelations to radiative…

High Energy Physics - Phenomenology · Physics 2009-11-11 Emanuel Katz , Ann E. Nelson , Devin G. E. Walker

We investigate the impact of dark Abelian gauge bosons on the electroweak precision measurements at the one-loop level. The dark gauge boson couples to the standard model fermions generally via two kinds of mixing with the electroweak gauge…

High Energy Physics - Phenomenology · Physics 2026-01-15 Cheng-Wei Chiang , Kazuki Enomoto

We compute the electroweak S and T parameters induced by SU(2)_L triplet scalars up to one-loop order. We consider the most general renormalizable potential for a triplet and the Standard Model Higgs doublet. Our calculation is performed by…

High Energy Physics - Phenomenology · Physics 2013-05-30 Zuhair U. Khandker , Daliang Li , Witold Skiba

We update the phenomenology of gauge singlet extensions of the Standard Model scalar sector and their implications for the electroweak phase transition. Considering the introduction of one real scalar singlet to the scalar potential, we…

High Energy Physics - Phenomenology · Physics 2015-03-05 Stefano Profumo , Michael J. Ramsey-Musolf , Carroll L. Wainwright , Peter Winslow

A nonuniversal abelian extension $\mathrm{U(1)}_{X}$ free from chiral anomalies is introduced into the Standard Model (SM), in order to evaluate its suitability in addressing the fermion mass hierarchy (FMH) by using seesaw mechanisms…

High Energy Physics - Phenomenology · Physics 2018-08-08 Carlos E. Díaz , S. F Mantilla , R. Martinez

In the case of minimal supersymmetric extension of the Standard Model (MSSM), when the pseudoscalar Higgs boson mass is less than the supersymmetry energy scale, the effective theory at the electroweak scale is a two-Higgs-doublet model. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Dubinin , A. Semenov

In a generic 'universal' theory of electroweak symmetry breaking, non fine-tuned heavy new physics affects the low-energy data through four parameters, which include and properly extend the generally insufficient S and T. Only by adding the…

High Energy Physics - Phenomenology · Physics 2009-10-09 Riccardo Barbieri , Alex Pomarol , Riccardo Rattazzi , Alessandro Strumia

We look for the minimal particle content which is necessary to add to the standard model in order to have a complete unification of gauge couplings and gravity at the weakly coupled heterotic string scale. Using the current precision…

High Energy Physics - Phenomenology · Physics 2009-11-11 D. Emmanuel-Costa , R. Gonzalez Felipe

A reexamination is made of one-loop oblique electroweak corrections. General definitions are given of the oblique parameters without reference to any $q^2$-expansion scheme. The old oblique parameters S,T and U are defined as differences of…

High Energy Physics - Phenomenology · Physics 2014-11-17 Anirban Kundu , Probir Roy

Recently proposed Little Higgs models present a viable solution to the naturalness problem of the Standard Model. An additional discrete symmetry, called T-parity, has been included in the simplest Little Higgs models to evade the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Debajyoti Choudhury , Dilip Kumar Ghosh

We explore the Higgs-Z-photon coupling in the Minimal Composite Higgs Model with vector and axial resonances. The electroweak precision measurement, i.e. S and T, is estimated for this model. We calculate the signal strength for Higgs decay…

High Energy Physics - Phenomenology · Physics 2014-04-14 Haiying Cai