Related papers: Proton stability in low-scale extra-dimensional gr…
Higgs boson production by the gluon fusion and its decay into two photons at the LHC are investigated in the context of the gauge-Higgs unification scenario. The qualitative behaviors for these processes in the gauge-Higgs unification are…
Extra dimension provides an attractive way to break symmetry by boundary conditions which can be useful to construct a natural grand unified theory avoiding the doublet-triplet splitting problem and the proton decay problem. It can provide…
The logarithmic running of the gauge couplings alpha_1, alpha_2 and alpha_3, indicates that they may unify at some scale M_GUT ~ 10^16. This is often taken to imply that the standard model gauge group is embedded into some larger simple…
We present a comprehensive study of an extended SU(5) grand unified theory (GUT) that incorporates a 45-dimensional Higgs representation to address the shortcomings of the minimal SU(5) GUT, such as the inability to generate realistic…
The transition from formulations with extra dimensions to Kaluza-Klein theories, aimed at extending the Standard Model, bears the ingredients of hidden symmetries and the Kaluza-Klein mechanism for mass generation. We explore these…
The lightest Kaluza-Klein particle appearing in models with universal extra dimensions has recently been proposed as a viable dark matter candidate when the extra dimensions are compactified on a scale of the order of 1 TeV. Underlying…
A complete 5-dimensional SU(5) unified theory is constructed which, on compactification on the orbifold with two different Z_2's (Z_2 and Z_2'), yields the minimal supersymmetric standard model. The orbifold accomplishes SU(5) gauge…
We present a five-dimensional supersymmetric SU(5) theory in which the gauge symmetry is broken maximally (i.e. at the 5D Planck scale M_*) on the same 4D brane where chiral matter is localized. Masses of the lightest Kaluza-Klein modes for…
I discuss in detail the construction of realistic superstring standard--like models in the four dimensional free fermionic formulation. The analysis results in a restricted class of models with unique characteristics: (i) Three and only…
A mechanism for the enhancement for proton lifetime in supersymmetric/supergravity (SUSY/SUGRA) grand unified theories (GUTs) and in string theory models is discussed where Higgsino mediated proton decay arising from color triplets…
Arkani-Hamed and Schmaltz (AS) have shown that proton stability need not originate from symmetries in a high energy theory. Instead the proton decay rate is suppressed if quarks and leptons are spatially separated in a compact extra…
It has been shown recently that the problem of rapid proton decay induced by dimension five operators arising from the exchange of colored Higgsinos can be simply avoided in grand unified models where a fifth spatial dimension is…
In the scenario of gauge-Higgs unification, the origin of the Higgs boson is higher dimensional gauge boson. Reflecting its origin, very characteristic predictions are made of the Higgs boson interactions in this scenario. Especially, a…
In grand unified theories based on orbifold constructions in higher dimensions, Higgsino-mediated proton decay is absent. However, proton decay mediated by $X$ and $Y$ gauge bosons is typically enhanced to levels detectable by current and…
We propose a grand unified model in five dimensions that addresses the strong CP problem. In this framework, the boundary conditions that break the unified gauge group into the Standard Model gauge group simultaneously explain the mass…
We discuss the stabilization of the scalar sector, including the radion, in the gauge model with one universal extra dimension, within Higgs and Higgsless scenarios. The stabilization occurs at the one-loop level, through the fermionic…
We discuss the possibility that the Higgs triplet can be light (1TeV in the most interesting case) without contradictions with the proton stability %and the gauge coupling unification in the context of higher dimensional theory. The proton…
Many theories of quantum gravity live in higher dimensions, and their reduction to four dimensions via mechanisms such as Kaluza-Klein compactification or brane world models have associated problems. We propose a novel mechanism of…
We show that the problem of stabilization of extra dimensions in Kaluza-Klein type cosmology may be solved in a theory of gravity involving high-order curvature invariants. The method suggested (employing a slow-change approximation) can…
F-theory GUTs provide a promising UV completion for models with approximate gauge coupling unification, such as the (non-supersymmetric) Standard Model. More specifically, if the superparters have masses well above the TeV scale, the…