Related papers: Amplitudes, recursion relations and unitarity in t…
We discuss the possibility of breaking the electroweak symmetry in theories with extra dimensions via boundary conditions, without a physical Higgs scalar in the spectrum. In these models the unitarity violation scale can be delayed via the…
We consider a two-Higgs doublet model extended with a broken Abelian gauge symmetry under which all Standard Model (SM) quarks, fourth generation fermions and a new SM-singlet scalar boson are charged. Such a setup is shown to be able to…
The WW scattering into gravitino and gaugino is here investigated in the broken phase, by using both gauge and mass eigenstates. Differently from what is obtained for unbroken gauge symmetry, we find in the scattering amplitudes new…
We consider a variant of the charge-Q compact Abelian-Higgs model, in which an Nf-dimensional complex vector is coupled with an Abelian Z_q gauge field. For Nf=2 and Q=1 we observe several transition lines that belong to the O(4), O(3), and…
Based on the general principles of Lorentz symmetry and unitary, we introduce two consistency conditions -- on-shell gauge symmetry and strong massive-massless continuation -- in constructing amplitudes of massive gauge theory with…
We establish the phase diagram of the five-dimensional anisotropic Abelian Higgs model by mean field techniques and Monte Carlo simulations. The anisotropy is encoded in the gauge couplings as well as in the Higgs couplings. In addition to…
I report on recent numerical simulations of the simplest field theory with cosmic string solutions, the Abelian Higgs model. We find that random networks of string quickly converge to a scaling solution in which the network scale length…
Calculations of high multiplicity Higgs amplitudes exhibit a rapid growth that may signal an end of perturbative behavior or even the need for new physics phenomena. As a step towards this problem we consider the quantum mechanical…
Using the recently introduced recursion relations with covariant massive-massless shift, we study tree-level scattering amplitudes involving a pair of massive vector bosons and an arbitrary number of gluons in the massive spinor-helicity…
We investigate the correlation between a possible deviation in the discovered Higgs boson $h(125)$ couplings from the Standard Model prediction and the mass scale ($M_{\text{2nd}}$) of the next-to-lightest Higgs boson in models with…
We present on the use of on-shell recursion relations. These can be used not only for calculating tree amplitudes, including those with masses, but also to compute analytically the missing rational terms of one-loop QCD amplitudes. Combined…
The weak-scale $U(1)_{Y}$ Abelian Higgs Model (AHM) is the spontaneous-symmetry-breaking gauge theory of a complex scalar $\phi = \frac{1}{\sqrt{2}}(H + i \pi)$ and a vector $A_{\mu}$. Global $U(1)_{Y}\otimes BRST$ symmetry emerges: when it…
We propose a minimal unified model of the electroweak interactions without a Higgs particle in the final physical spectrum. This is achieved through adding a nonlinear constraint for the Higgs field in the Lagrangian in which the field's…
The Littlest Higgs Model is constrained using the tree-level perturbative arguments, similar to those employed to obtain the Higgs mass bound. It is found that the perturbative unitaity violations set in at energy scales $\sim 1.5\chi f$,…
Recently there has been interest in electroweak models on a five dimensional interval that break the symmetry without a higgs boson. By warping the metric of the interval it may be possible to avoid experimental bounds on extra W bosons and…
We study the high-temperature phase transitions for the Abelian and $SU(2)$ Higgs models, using the exact renormalization group. The evolution equation for a properly-defined coarse-grained free energy is solved. The phase diagram of the…
We use tree-level perturbation theory to show how non-supersymmetric one-loop scattering amplitudes for a Higgs boson plus an arbitrary number of partons can be constructed, in the limit of a heavy top quark, from a generalization of the…
We derive general tree-level recursion relations for amplitudes which include massive propagating particles. As an illustration, we apply these recursion relations to scattering amplitudes of gluons coupled to massive scalars. We provide…
We study the phase diagram and phase transitions of the three dimensional multicomponent lattice Higgs model with non-compact Abelian discrete groups. The model with non-compact U(1) gauge group is known to undergo, for a sufficiently large…
We examine the gauge dependence of lower bounds on the Higgs mass obtained from the requirement that the electroweak vacuum be the global minimum of the effective potential. We study a simple model, the spontaneously-broken Abelian Higgs…