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We study tree level corrections to precision electroweak physics in the recently proposed Higgsless models in warped space. Such models inherit from their similarity with technicolor theories a large contribution to the oblique parameters,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Giacomo Cacciapaglia

We study a class of non-exotic minimal $U(1) '$ extensions of the Standard Model, which includes all scenarios that are anomaly-free with the ordinary fermion content augmented by one Right-Handed neutrino per generation, wherein the new…

High Energy Physics - Phenomenology · Physics 2017-04-25 Elena Accomando , Claudio Coriano , Luigi Delle Rose , Juri Fiaschi , Carlo Marzo , Stefano Moretti

Using newly proposed BCF/BCFW recursion relations, compact formulas are obtained for tree-level n-gluon amplitudes of helicity structure --++...+. We then make an extension of these recursion relations to include fermions of multi-flavors,…

High Energy Physics - Theory · Physics 2008-11-26 Mingxing Luo , Congkao Wen

Electroweak precision data have been extensively used to constrain models containing physics beyond that of the Standard Model. When the model contains Higgs scalars in representations other than singlets or doublets, and hence rho not…

High Energy Physics - Phenomenology · Physics 2014-11-18 Mu-Chun Chen , Sally Dawson , Tadas Krupovnickas

Electroweak precision data has been extensively used to constrain models containing physics beyond that of the Standard Model. When the model contains Higgs scalars in representations other than SU(2) singlets or doublets, and hence rho not…

High Energy Physics - Phenomenology · Physics 2010-04-15 Mu-Chun Chen , Sally Dawson , C. B. Jackson

We propose a generic framework in which the Higgs and the unparticle are both composite. The underlying theories are four dimensional, asymptotically free, nonsupersymmetric gauge theories with fermionic matter. We sketch a possible uni-…

High Energy Physics - Phenomenology · Physics 2009-02-18 Francesco Sannino , Roman Zwicky

We show that scalar unparticles coupled to the Standard Model Higgs at the renormalizable level can have a dramatic impact in the breaking of the electroweak symmetry already at tree level. In particular one can get the proper electroweak…

High Energy Physics - Phenomenology · Physics 2008-11-26 Antonio Delgado , Jose R. Espinosa , Mariano Quiros

We examine the Abelian Higgs model in (d+1)-dimensional anti-de Sitter space with an ultraviolet brane. The gauge symmetry is broken by a bulk Higgs vacuum expectation value triggered on the brane. We propose two separate Goldstone boson…

High Energy Physics - Theory · Physics 2024-06-04 Ian Chaffey , Sylvain Fichet , Philip Tanedo

In high-energy collisions far above the electroweak scale, the effects of electroweak symmetry breaking are expected to become parametrically small $\delta \sim M_W/E$. This defines the extent to which the electroweak gauge symmetry is…

High Energy Physics - Phenomenology · Physics 2025-08-12 Rodolfo Capdevilla , Tao Han

Na\"ive dimensional analysis seems to suggest possible unitarity violations in the framework of the Higgs and new Higgs inflationary scenarios. These violations seem to happen around the value in which the potential energy, per given Higgs…

High Energy Physics - Phenomenology · Physics 2017-06-28 Albert Escrivà , Cristiano Germani

We study the two-dimensional lattice multicomponent Abelian-Higgs model, which is a lattice compact U(1) gauge theory coupled with an N-component complex scalar field, characterized by a global SU(N) symmetry. In agreement with the…

Statistical Mechanics · Physics 2020-02-19 Claudio Bonati , Andrea Pelissetto , Ettore Vicari

We prove that all open string theory disc amplitudes in a flat background obey Britto-Cachazo-Feng-Witten (BCFW) on-shell recursion relations, up to a possible reality condition on a kinematic invariant. Arguments that the same holds for…

High Energy Physics - Theory · Physics 2010-12-01 Rutger H. Boels , Daniele Marmiroli , Niels A. Obers

We study the scattering of longitudinally polarized W bosons in extensions of the Standard Model where anomalous Higgs couplings to gauge sector and higher order O(p^4) operators are considered. These new couplings with respect to the…

High Energy Physics - Phenomenology · Physics 2014-08-06 Domenec Espriu , Federico Mescia

We consider a Higgs boson coupled to gluons via the five-dimensional effective operator H tr G_{\mu\nu}G^{\mu\nu}. We treat H as the real part of a complex field phi that couples to the selfdual gluon field strengths and compute the…

High Energy Physics - Phenomenology · Physics 2009-02-09 E. W. N. Glover , Pierpaolo Mastrolia , Ciaran Williams

In general electroweak models with weakly coupled (and otherwise arbitrary) Higgs sector there always exists in the spectrum a scalar state with mass controlled by the electroweak scale. A new and simple recipe to compute an analytical…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. Comelli , J. R. Espinosa

In this paper, we investigate how the LHC data limit the Higgs-related couplings in the effective description of a strongly interacting extension of the Standard model. The Higgs boson is introduced as a scalar composite state and it is…

High Energy Physics - Phenomenology · Physics 2016-12-12 Mikulas Gintner , Josef Juran

Tree-level unitarity constraints on the masses of the Higgs bosons in the general Two Higgs Doublet Model (THDM) are studied. We first consider the case where the Higgs potential is invariant under a discrete symmetry transformation, and…

High Energy Physics - Phenomenology · Physics 2011-09-29 Andrew Akeroyd , Abdesslam Arhrib , El--Mokhtar Naimi

In this paper, we study the tree amplitudes with gluons coupled to gravitons. We first study the relations among the mixed amplitudes. With BCFW on-shell recursion relation, we will show the color-order reversed relation, $U(1)$-decoupling…

High Energy Physics - Theory · Physics 2011-01-27 Yi-Xin Chen , Yi-Jian Du , Bo Feng

We analyze the validity of BCFW recursion relations for currents of n - 2 gluons and two massive quarks, where one of the quarks is off shell and the remaining particles are on shell. These currents are gauge-dependent and can be used as…

High Energy Physics - Theory · Physics 2013-01-07 Ruth Britto , Alexander Ochirov

In these proceedings I describe the use of tree level unitarity to constrain top quark signatures of Higgsless electroweak models and discuss implications for collider phenomenology.

High Energy Physics - Phenomenology · Physics 2008-11-26 Christian Schwinn