English
Related papers

Related papers: Minimal Lee-Wick Extension of the Standard Model

200 papers

We discuss electroweak constraints on TeV scale extensions of the standard model. To obtain model-independent results, effective theory approach is adopted. Constraints are given on arbitrary linear combinations of a set of dimension-6…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhenyu Han

We propose the minimal, lepton-number conserving, SU(3)xSU(2)xU(1) gauge-singlet, or phantom, extension of the Standard Model. The extension is natural in the sense that all couplings are of O(1) or forbidden due to a phantom sector global…

High Energy Physics - Phenomenology · Physics 2009-11-11 D. G. Cerdeno , A. Dedes , T. E. J. Underwood

We derive the leptonic neutral current in the simplest little Higgs model and compute the contribution of the model to the decay width $Z \to e^+e^-$. Using the precision electroweak data we obtain a strong lower bound $f\geq 5.6$ TeV at…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alex G. Dias , C. A. de S. Pires , P. S. Rodrigues da Silva

We present the constraints on the parameter space of the Lee-Wick Standard Model coming from electroweak precision observables. The model predicts a large positive S and a negative T. We show that it is possible to find some regions in…

High Energy Physics - Phenomenology · Physics 2008-10-21 Ezequiel Alvarez , Leandro Da Rold , Carlos Schat , Alejandro Szynkman

As a first step towards the construction of a general electroweak effective Lagrangian incorporating heavy states, we present here a simplified version where only vector and axial-vector spin-1 triplets are involved. We adopt an effective…

High Energy Physics - Phenomenology · Physics 2019-01-29 Joaquín Santos , Ignasi Rosell , Antonio Pich , Juan José Sanz-Cillero

I describe, from the bottom up, a sequence of natural effective field theories. Below a TeV we have the minimal standard model with a light Higgs, and an extra neutral scalar. In the 1-10 TeV region these scalars are part of a multiplet of…

High Energy Physics - Phenomenology · Physics 2017-08-23 Ann E. Nelson

Electroweak symmetry can be naturally broken by observed quark and gauge fields in various extra-dimensional configurations. No new {\it fundamental} fields are required below the quantum gravitational scale ($\sim$ 10 - 100 TeV). We…

High Energy Physics - Phenomenology · Physics 2009-10-31 Hsin-Chia Cheng , Bogdan A. Dobrescu , Christopher T. Hill

We treat the Standard Model as the low-energy limit of an effective field theory that incorporates higher-dimensional operators to capture the effects of decoupled new physics. We consider the constraints imposed on the coefficients of…

High Energy Physics - Phenomenology · Physics 2014-10-29 John Ellis , Veronica Sanz , Tevong You

If electroweak symmetry breaking arises via strong dynamics, electroweak precision tests and flavour physics experiments suggest that the minimal model should closely resemble the Standard Model at the LHC. I describe two directions going…

High Energy Physics - Phenomenology · Physics 2010-05-07 Ben Gripaios

In this note we present a little Higgs model that has custodial SU(2) as an approximate symmetry. This theory is a simple modification of the ``Minimal Moose'' with SO(5) global symmetries protecting the Higgs mass. This allows for a simple…

High Energy Physics - Phenomenology · Physics 2011-01-13 Spencer Chang , Jay G. Wacker

We present an update of the global fit of the Standard Model electroweak sector to latest experimental results. We include new kinematic top quark and $W$ boson mass measurements from the LHC, a $\sin^2\theta^{\ell}_{\mathrm{eff}}$ result…

High Energy Physics - Phenomenology · Physics 2019-12-16 Johannes Haller , Andreas Hoecker , Roman Kogler , Klaus Mönig , Thomas Peiffer , Jörg Stelzer

Recently a new class of theories of electroweak symmetry breaking have been constructed. These models, based on deconstruction and the physics of theory space, provide the first alternative to weak-scale supersymmetry with naturally light…

High Energy Physics - Phenomenology · Physics 2011-01-13 N. Arkani-Hamed , A. G. Cohen , T. Gregoire , E. Katz , A. E. Nelson , J. G. Wacker

We study the exact (one-loop) effective potential of the littlest Higgs model and determine the dependence of physical quantities, such as the vacuum expectation value v_W and mass m_h of the Higgs boson, on the fundamental parameters of…

High Energy Physics - Phenomenology · Physics 2009-11-11 F. Bazzocchi , M. Fabbrichesi , M. Piai

Little Higgs models offer a new way to address the hierarchy problem, and give rise to a weakly-coupled Higgs sector. These theories predict the existence of new states which are necessary to cancel the quadratic divergences of the Standard…

High Energy Physics - Phenomenology · Physics 2009-11-07 J. L. Hewett , F. J. Petriello , T. G. Rizzo

We review the experimental and theoretical status of the standard electroweak theory, and its fundamental parameters. We obtain the global best fit result for the Standard Model Higgs boson of M_H = 107^{+67}_{-45} GeV, and find the 95%…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jens Erler , Paul Langacker

Due to the mass gap between the Standard Model and possible New Physics states, electroweak effective approaches are appropriate. Although a linear realization of the electroweak symmetry breaking with the Higgs forming a doublet together…

High Energy Physics - Phenomenology · Physics 2019-10-07 Ignasi Rosell , Claudius Krause , Antonio Pich , Juan José Sanz-Cillero

A realistic SU(3)_C x SU(3)_W unified theory is constructed with a TeV sized extra dimension compactified on the orbifold S_1/Z_2, leaving only the standard model gauge group SU(3)_C x SU(2)_L x U(1)_Y unbroken in the low energy 4D theory.…

High Energy Physics - Phenomenology · Physics 2009-09-29 Lawrence J. Hall , Yasunori Nomura

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

Using effective field theory approach, we study the constraints from electroweak data on the SU(5)/SO(5), SU(6)/SP(6), SU(3)xU(1) little Higgs models and their variations. We construct an effective theory valid above the electroweak…

High Energy Physics - Phenomenology · Physics 2009-11-11 Zhenyu Han , Witold Skiba

We make a first matching of the real Higgs triplet extension (RHTE) of the standard model to the Higgs effective field theory (HEFT), which is also known as electroweak chiral Lagrangian (EWChL). In the RHTE, the ratio $\xi$ of two VEVs…

High Energy Physics - Phenomenology · Physics 2025-03-04 Huayang Song , Xia Wan