Related papers: Are Low-energy Data already Hinting at Five Dimens…
It is known that the recently reported shift of the W boson mass can be easily explained by an $SU(2)_L$ triplet Higgs boson with a zero hypercharge if it obtains a vacuum expectation value (VEV) of $O(1)$ GeV. Surprisingly, the addition of…
We construct a top-mode standard model where the third generation fermions and the SU(2)_L \times U(1)_Y gauge bosons are put on a 6-dimensional brane(5-brane) with the extra dimensions compactified on the TeV scale(R_5^{-1}=R_6^{-1} \equiv…
We examine a model with multiple scalar fields to see whether it is possible to reduce the fine- tuning of the SM Higgs mass without introducing low scale top partners. Our approach may be regarded as a generalization of the condition…
We look for the minimal particle content which is necessary to add to the standard model in order to have a complete unification of gauge couplings and gravity at the weakly coupled heterotic string scale. Using the current precision…
We study supersymmetric unified models with three fermion generations based on the gauge group $SO(10)$ and require Gauge-Yukawa Unification, i.e., a renormalization group invariant functional relationship among the gauge and Yukawa…
A $Z_2$ symmetry that extends the weak interaction, $SU(2)_L \rightarrow SU(2)_L \times SU(2)'$, and the Higgs sector, $H(2) \rightarrow H(2,1) + H'(1,2)$, yields a Standard Model quartic coupling that vanishes at scale $v' = <H'>~\gg~<H>$.…
Anomalously light fermionic partners of the top quark often appear in explicit constructions, such as the 5d holographic models, where the Higgs is a light composite pseudo Nambu-Goldstone boson and its potential is generated radiatively by…
We review the possibility that the Supersymmetric Standard Model arises from orbifold constructions of the E_8 x E_8 Heterotic Superstring, and the phenomenological properties that such a model should have. In particular, trying to solve…
Warped extra dimensions allow a novel way of solving the hierarchy problem, with all fundamental mass parameters of the theory naturally of the order of the Planck scale. The observable value of the Higgs vacuum expectation value is…
The top quark seesaw mechanism offers a method for constructing a composite Higgs field without the usual difficulties that accompany traditional technicolor or topcolor theories. The focus of this article is to study the phenomenology of…
We interpret the recent discovery of a 125 GeV Higgs-like state in the context of a two Higgs doublets model with a heavy 4th sequential generation of fermions, in which one Higgs doublet couples only to the 4th generation fermions, while…
The recently announced Higgs discovery marks the dawn of the direct probing of the electroweak symmetry breaking sector. Sorting out the dynamics responsible for electroweak symmetry breaking now requires probing the Higgs interactions and…
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…
If the Higgs does not propagate into an otherwise universal extra dimension, then tree-level Kaluza-Klein number is not conserved in the Yukawa interactions. This leads to mixing between zero-mode fermions and their associated Kaluza-Klein…
We study the fermionic couplings of the neutral Higgs bosons in the THDM, assuming a four-texture structure for the Yukawa matrices. We then derive the low-energy constraints on the model, focusing in b-quark and lepton physics, and apply…
We discuss gauge coupling unification in models with additional 1 to 4 complete vector-like families, and derive simple rules for masses of vector-like fermions required for exact gauge coupling unification. These mass rules and the…
Little Higgs models predict new gauge bosons, fermions and scalars at the TeV scale that stabilize the Higgs mass against quadratically divergent one-loop radiative corrections. We categorize the many little Higgs models into two classes…
We study a five dimensional SU(3) nonsupersymmetric gauge theory compactified on $M^4\times S^1/Z_2$ and discuss the gauge hierarchy in the scenario of the gauge-Higgs unification. Making use of calculability of the Higgs potential and a…
Motivated by the recent precision measurements of the W boson mass and top quark mass, we test the Littlest Higgs model by confronting the prediction of M_W with the current and prospective measurements of M_W and M_t as well as through the…
We study the Two-Higgs-Doublet Model predicted in the minimal theory for quark-lepton unification that can describe physics at the low scale. We discuss the relations among the different decay widths of the new Higgs bosons and study their…