Related papers: Alignment, reverse alignment, and wrong sign Yukaw…
It is well-known that the $SU(5)$ grand unified theory, with the standard model quarks and leptons unified in $\overline{5}$ and $10$ and the electroweak Higgs doublet residing in $5$ dimensional representations, leads to relation,…
With discovery of the 125 GeV boson $h^0$, the existence of a second doublet is very plausible. We show that the "alignment" phenomenon, that $h^0$ is found to resemble closely the Standard Model Higgs boson, may correspond to Higgs quartic…
It is pointed out that in supersymmetric models with a new gauge symmetry under which the Higgs is charged, the fine-tuning of the electroweak symmetry breaking is relaxed due to suppression of the top Yukawa coupling at higher scales by a…
There is a $+2\sigma$ deviation in the average Higgs-signal strength for all the $7+8+13$ TeV data up to Summer 2018. We find that a slight reduction of the bottom-Yukawa coupling can fit the data better than the standard model. We suggest…
The vacuum stability lower bound on the mass of the Higgs boson is numerically investigated in an $SU(2)_L \otimes SU(2)_R$ symmetric Yukawa model, which describes two heavy degenerate fermion doublets in the limit of vanishing gauge…
With the hypothesis of minimal flavor violation, we find that there exists a power-aligned relation between the Yukawa couplings of the two scalar doublets in the two-Higgs-doublet model with Hermitian Yukawa matrices. Within such a…
LHC has found hints for a Higgs particle of 125 GeV. We investigate the possibility that such a particle is a mixture of scalar and pseudoscalar states. For definiteness, we concentrate on a two Higgs doublet model with explicit CP…
The feasibility of measuring the Higgs-boson properties at the Photon Collider at TESLA has been studied in detail for masses between 200 and 350 GeV, using realistic luminosity spectra and detector simulation. We consider the Two Higgs…
We present new variants of the Two Higgs-Doublet Model where all Yukawa couplings with physical Higgs bosons are controlled by the quark mixing matrices of both chiralities, as well as, in one case, the ratio between the two scalar…
The latest LHC data confirmed the existence of a Higgs-like particle and made interesting measurements on its decays into $\gamma \gamma$, $Z Z^\ast$, $W W^\ast$, $\tau^+ \tau^-$, and $b \bar{b}$. It is expected that a decay into $Z \gamma$…
I discuss standard motivation for the new physics at the 1 TeV scale. Although the arguments for new exotic phenomena seem to be very supportive I argue that the Standard Model still might offer a good description far beyond this energy…
The data accumulated so far confirm the Higgs-like nature of the new boson discovered at the LHC. The Standard Model Higgs hypothesis is compatible with the collider results and no significant deviations from the Standard Model have been…
Many extensions to the Standard Model imply the existence of new charged scalar Higgs bosons. We study the contribution of a general scalar or pseudoscalar coupling for the neutrino-electron scattering. We take a phenomenological approach…
In the two Higgs doublet model, natural flavour conservation can be achieved through the use of a discrete Z2 symmetry. A less restrictive condition is the requirement of alignment in the Yukawa sector. So far, alignment has been an anzatz,…
Testing the properties of the Higgs particle discovered at the LHC and searching for new physics signals, are some of the most important tasks of Particle Physics today. Current measurements of the Higgs couplings to fermions and gauge…
We consider a twin Higgs scenario where the $Z_2$ twin symmetry is broken spontaneously, not explicitly. This scenario provides an interesting interpretation of the Higgs metastability in the standard model; the $SU(4)$ breaking scale $f$…
The properties of the Higgs boson discovered at the Large Hadron Collider are very well described by the Standard Model (SM). Thus, any theory that invokes an extended Higgs sector must explain why the neutral scalar observed at the LHC so…
We discuss the testability of CP-violating phases at future lepton colliders for the scenario which satisfies electric dipole moment data by destructive interferences among several phases. We consider the general but aligned two Higgs…
We discuss the effect of CP violation in the aligned scenario of the general two-Higgs-doublet model, in which the Higgs potential and the Yukawa interaction provide additional CP-violating phases. An alignment is imposed to the Yukawa…
Searches for new neutral Higgs bosons of an extended Higgs sector at the LHC can be interpreted in the framework of the two-Higgs doublet model. By employing generic flavor-aligned Higgs-fermion Yukawa couplings, we propose an analysis that…