Related papers: Vacuum stability bounds on Higgs coupling deviatio…
The measured (central) values of the Higgs and top quark masses indicate that the Standard Model (SM) effective potential develops an instability at high field values. The scale of this instability, determined as the Higgs field value at…
We discuss a minimal extension to the standard model in which there are two Higgs bosons and, in addition to the usual fermion content, two fermion doublets and one fermion singlet. The little hierachy problem is solved by the vanishing of…
We examine the effects of new physics effecting the Higgs sector of the standard model, focusing on the effects on the Higgs self couplings. We demonstrate that a low mass higgs, m_h < 2 m_t, can have a strong effective self coupling due to…
The existing constraints from particle colliders reveal a suspicious but nonlethal metastability for our current electroweak vacuum of Higgs potential in the standard model of particle physics, which is, however, disfavored in the early…
The parameters of the Higgs potential of the Minimal Supersymmetric Standard Model (MSSM) receive large radiative corrections which lift the mass of the lightest Higgs boson to the measured value of 126 GeV. Depending on the MSSM…
The Higgs-Top model is studied by a non-perturbative variational extension of the Gaussian Effective Potential that incorporates fermions. In the limit of a very strong Yukawa coupling the one-loop result is shown to follow a…
We investigate the stability of the electroweak vacuum for two-Higgs doublet models with a supersymmetric UV completion. The supersymmetry breaking scale is taken to be of the order of the grand unification scale. We first study the case…
This is an addendum to the paper of the above title published in Physics Letters B317, 159 (1993). In that paper, I found the lower bound to the Higgs mass as a function of the top quark mass one obtains by requiring that the standard model…
Inclusive Standard Model Higgs boson pair production at hadron colliders has the capability to determine the Higgs boson self-coupling, lambda. We present a detailed analysis of the gg\to HH\to (W^+W^-)(W^+W^-)\to…
After the discovery of the Higgs boson at the LHC, it is natural to start the research program on the precision study of the Higgs-boson couplings to various standard model (SM) particles. We provide a generic framework for the deviations…
We analyse the possibility that, in two Higgs doublet models, one or more of the Higgs couplings to fermions or to gauge bosons change sign, relative to the respective Higgs Standard Model couplings. Possible sign changes in the coupling of…
We address the notorious metastability of the standard model (SM) and promote it to a model building task: What are the new ingredients required to stabilize the SM up to the Planck scale without encountering subplanckian Landau poles?…
In the MSSM, the Higgs couplings to down-type quarks and leptons, normalized with respect to their corresponding Standard Model values, coincide at tree-level and this degeneracy is only slightly broken at the quantum level. Motivated by…
We explore a scenario in the Standard Model in which dimension four Yukawa couplings are either forbidden by a symmetry, or happen to be very tiny, and the Yukawa interactions are dominated by effective dimension six interactions. In this…
The Large Electron-Positron (LEP) collider experiments have constrained the mass of the Standard Model (SM) Higgs boson to be above 114.4 GeV. This bound applies to all extensions of the SM where the coupling of a Higgs boson to the Z boson…
We perform a global analysis of the constraints on a possible Higgs-like particle with mass ~ 125 GeV that are provided by the ATLAS, CDF, CMS and D0 experiments. We combine the available constraints on possible deviations from the Standard…
Upon the absence of signals of new physics at the LHC, a reasonable strategy is to assume that new particles are very heavy and the other model parameters are unknown yet. In the aligned two Higgs doublet model, however, heavy Higgs boson…
We study constraints from perturbativity and vacuum stability as well as the EWPD in the type II seesaw model. As a result, we can put stringent limits on the Higgs triplet couplings depending on the cut-off scale. The EWPD tightly…
We discuss the current status of theoretical and experimental constraints on the real Higgs singlet extension of the Standard Model. For the second neutral (non-standard) Higgs boson we consider the full mass range from 1 GeV to 1 TeV…
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…