Related papers: Nullification of multi-Higgs threshold amplitudes …
Barbieri and Hall have argued that threshold effects at the scale of grand-unification wipe out predictions on the SUSY scale, M_S. Using triviality arguments we give upper bounds on ultraheavy particles, while proton stability gives lower…
In the standard model in universal extra dimensions (UED) the mass of the Higgs field is driven to the cutoff of the higher-dimensional theory. This re-introduces a small hierarchy since the compactification scale 1/R should not be smaller…
It is pointed out (not for the first time) that the minimal Standard Model, without additional gauge-singlet right-handed neutrinos or isotriplet Higgs fields, allows for nonvanishing neutrino masses and mixing. The required interaction…
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…
We classify all possible new scalar particles that can have renormalizable linear couplings to Standard Model fields and therefore be singly produced at colliders. We show that this classification exhausts the list of heavy scalar particles…
We study the possible annihilation cross section of scalar dark matter and its coupling \lambda_D to the standard model Higgs in the case of the electroweak symmetry breaking driven by unparticle. Here the annihilation process occurs with…
It has been suggested that electroweak symmetry breaking in the Standard Model may be natural if the Standard Model merges into a conformal field theory (CFT) at short distances. In such a scenario the Higgs mass would be protected from…
We study the Higgs-boson mass spectrum of the minimal supersymmetric standard model, in which the tree-level CP invariance of the Higgs potential is broken explicitly by loop effects of soft-CP-violating Yukawa interactions related to…
Triviality and vacuum stability bounds on the Higgs and top quark masses in a rather general class of supersymmetric extensions of the Standard Model are compared with the corresponding bounds without supersymmetry. Due to generic…
The two Higgs doublet model has a rich vacuum structure, including the possibility of existence of two Standard Model-like minima at tree-level. It is therefore possible that the universe's vacuum is metastable, and a deeper minimum exists.…
Nonperturbative triviality and vacuum stability mass bounds are obtained for the Higgs scalar and top quark degrees of freedom in the standard electroweak model using Wilson renormalization group techniques. Particular attention is given to…
We obtain tree-level unitarity constraints for the most general Two Higgs Doublet Model (2HDM) with explicit CP-violation. We briefly discuss correspondence between possible violation of tree level unitarity limitation and physical content…
The properties of the recently discovered Higgs boson together with the absence of new physics at collider experiments allows us to speculate about consistently extending the Standard Model of particle physics all the way up to the Planck…
We analyze the prospects of measuring the parity of Higgs particles in the Standard Model and its supersymmetric extensions. Higgs decays are discussed in this context as well as production processes including, in particular, the fusion of…
Threshold amplitudes are considered for multi-particle production in $\phi^k$ and $O(N) ~\phi^4$ theories. It is found that the disappearance of tree-level threshold amplitudes of $2$ on-shell particles producing a large number of particles…
We present bounds on the Higgs mass in the Standard Model and in the Minimal Supersymmetric Standard Model using the effective potential with next-to-leading logarithms resummed by the renormalization group equations, and physical (pole)…
The minimal supersymmetric standard model, and extensions, predicts a relatively light higgs particle if one supposes perturbativity until high scales. That fact is in conflict with nowadays data coming from LEPII fruitless searches for the…
The standard model is a remarkably consistent and complete quantum field theory but its coupling to gravity and the Higgs field remain problematic, as reflected in the cosmological constant problem, the Weyl anomaly, and the hierarchy…
Recently a new recursion relation for tree-level gluon amplitudes in gauge theory has been discovered. We solve this recursion to obtain explicit formulas for the closed set of amplitudes with arbitrarily many positive and negative helicity…
We compute a unitarity bound for higgs mass using one--loop corrected s--wave partial amplitude for $Z_L Z_L \rightarrow Z_L Z_L$ scattering. We use the equivalence theorem and show that the higgs mass has to be less than $\approx 600$ GeV…