Related papers: Unitarity Constraints on non-minimal Universal Ext…
Motivated by scalar-tensor gravities, we consider a theory which contains massless scalar fields with different sound speeds. We derive unitarity relations for partial wave amplitudes of $2 \to 2$ scattering, with explicit formulas for…
We investigate the Kaluza--Klein (KK) spectrum of N=1 supersymmetric gauge theory compactified on a circle. We concentrate on a model with gauge group SU(2) and four massless matter fields in the fundamental representation. We derive the…
We study bounds on Higgs boson masses from perturbative unitarity in the Georgi-Machacek model, whose Higgs sector is composed of a scalar isospin doublet, a real and a complex isospin triplet fields. This model can be compatible with the…
We analyze the exclusive rare $B \to K^{(*)} \ell^+ \ell^-$, $B \to K^{(*)} \nu \bar \nu$ and $B \to K^* \gamma$ decays in the Applequist-Cheng-Dobrescu model, an extension of the Standard Model in presence of universal extra dimensions. In…
We obtain the partial-wave unitarity constraints on dimension-six operators stemming from the analyses of vector boson and Higgs scattering processes as well as the inelastic scattering of standard model fermions into electroweak gauge…
We reconsider the constraints on Universal Extra Dimensions (UED) models arising from precision electroweak data. We take into account the subleading contributions from new physics (expressed in terms of the X,Y ... variables), as well as…
We have combined perturbative unitarity and renormalisation group equation arguments in order to find a dynamical way to constrain the space of the gauge couplings ($g'_1$, $\widetilde{g}$) of the so-called "Minimal $Z'$ Models". We have…
We study five-dimensional Yang-Mills theories compactified on an S^1/Z_2 orbifold. The fundamental Lagrangian naturally includes brane kinetic terms at the orbifold fixed points which are induced by quantum corrections of the bulk fields.…
Recently the spectrum of KK modes in the framework of one flat extra-dimensional scenario was revisited in the paper Phys. Rev. D74 (2006) 124013, (hep-th/0607246) on the basis of self-adjoint extension of the quantum mechanical operator…
Unitarity constraints on the scalar parameters both for the Standard Model and the general Two Higgs Doublet Model (THDM) are examined. In the case of the THDM with an exact discrete symmetry transformation, we show that the mass of the…
We present a unified, SI-consistent framework to constrain minimal SME coefficients $a_\mu$ and $b_\mu$ using magnetically confined two-dimensional electron systems under a uniform magnetic field. Working in the nonrelativistic…
Five-dimensional field theories compactified on an S^1/Z_2 orbifold naturally include local brane kinetic terms at the orbifold fixed points at the tree as well as the quantum level. We study the quantization of these theories before the…
The recent up to 2fb^{-1} of data from the ATLAS and CMS experiments at the CERN Large Hadron Collider at 7TeV put an upper bound on the production cross section of a Higgs-like particle. We translate the results of the H -> WW -> l nu l nu…
We study two-to-two scattering amplitudes of a scalar particle of mass $m$. For simplicity, we assume the presence of $\mathbb{Z}_2$ symmetry and that the particle is $\mathbb{Z}_2$ odd. We consider two classes of amplitudes: the fully…
We obtain the partial-wave unitarity constraints on the lowest-dimension effective operators which generate anomalous quartic gauge couplings but leave the triple gauge couplings unaffected. We consider operator expansions with linear and…
We investigate the scalar K pi form factor at low energies by the method of unitarity bounds adapted so as to include information on the phase and modulus along the elastic region of the unitarity cut. Using at input the values of the form…
We consider variations of coupling strengths and mass ratios in and beyond the Standard Model, in the light of various mechanisms of mass generation. In four-dimensional unified models, heavy quark and superparticle thresholds and the…
We present a comprehensive reassessment of perturbative unitarity bounds in the dimension-six Standard Model Effective Field Theory, exploiting a new formalism based on spinor-helicity techniques to derive partial-wave unitarity bounds for…
In this article we study Kaluza-Klein (KK) dimensional reduction of massive Abelian gauge theories with charged matter fields on a circle. Since local gauge transformations change position dependence of the charged fields, the decomposition…
The Kaluza-Klein (KK) modes of a massive scalar field on a 3-brane embedded in six dimensional multiply warped spacetime are determined. Due to the presence of warping along both the extra dimensions the KK mass spectrum splits into two…