Related papers: New Weak-Scale Physics from SO(10) with High-Scale…
We consider an SO(10) grand unified theory in which the ratio of the SU(2)_W and SU(3)_c gaugino masses satisfy M_2/M_3 \approx 3, which results in the realization of natural supersymmetry. In the MSSM parameter space this relation looks…
Even if the concerns related to the naturalness of the electroweak scale are repressed, the Higgs mass and stability of the electroweak vacuum do not allow arbitrarily large supersymmetry breaking scale, $M_S$, in the minimal models with…
We show how gauge coupling unification near the Planck scale $M_P\sim 10^{19}$ GeV can be achieved in the framework of supersymmetry, facilitating a full unification of all forces with gravity. Below the conventional GUT scale $M_{GUT}\sim…
A low intermediate scale within minimal supersymmetric SO(10) GUTs is a desirable feature to accommodate leptogenesis. We explore this possibility in models where the intermediate gauge symmetry breaks spontaneously by (a) doublet Higgs…
The evolution of Standard Model gauge couplings is studied in a non-supersymmetric scenario in which the hierarchy problem is resolved by Higgs compositeness above the weak scale. It is argued that massiveness of the top quark combined with…
We extend the nonsupersymmetric SO(10) grand unification theories by adding a horizontal symmetry, which connects the three generations of fermions. Without committing to any specific symmetry group, we investigate the 1-loop…
There are a lot of works within a class of classically scale invariant model, which is motivated by solving the gauge hierarchy problem. In this context, the Higgs mass vanishes at the UV scale due to the classically scale invariance, and…
We develop a bottom-up holographic model that provides the dual description of a strongly coupled field theory, in which the spontaneous breaking of an approximate global symmetry yields the SO(5)/SO(4) coset relevant to minimal…
We systematically construct two kinds of models with canonical gauge coupling unification and universal high-scale supersymmetry breaking. In the first we introduce standard vector-like particles while in the second we also include…
We present a renormalizable non supersymmetric Grand Unified SO(10) model which, at the price of a large fine tuning, is compatible with all compelling phenomenological requirements below the unification scale and thus realizes a minimal…
In theories with extra dimensions the Standard Model Higgs field can be identified with the internal components of higher-dimensional gauge fields (Higgs-gauge unification). The higher-dimensional gauge symmetry prevents the Higgs mass from…
We investigate the prospects to achieve unification of the gauge couplings in models without supersymmetry. We restrict our discussion to $SU(5), SO(10)$ and $E_6$ models that mimic the structure of the Standard Model as much as possible…
The Standard Model may be included within a supersymmetric theory, postulating new sparticles that differ by half-a-unit of spin from their standard model partners, and by a new quantum number called R-parity. The lightest one, usually a…
We discuss two classes of supersymmetric grand unified theories based on extended gauge groups $SO(10) \times SO(10)$ and $SO(10)\times SO(10)\times SO(10)$. Effective adjoint fields of each gauge group SO(10) are argued to be formed from…
The minimal supersymmetric standard model, and extensions, have stringent upper bounds on the mass of the lightest Higgs boson if perturbativity up to the Planck scale is assumed. We argue that these bounds are softened tremendously if the…
We discuss how a model for the electroweak interactions without a Higgs could be embedded into a grand unified theory. The requirement of a non-trivial fixed point in the SU(2) sector of the weak interactions together with the requirement…
We analyze a gauge-Higgs unification model which is based on a gauge theory defined on a six-dimensional spacetime with an $S^2$ extra-space. We impose a symmetry condition for a gauge field and non-trivial boundary conditions of the $S^2$.…
A new supersymmetric standard model based on N=1 supergravity is constructed, aiming at natural explanation for the proton stability without invoking an ad hoc discrete symmetry through R parity. The proton is protected from decay by an…
We construct a model unifying gravity with weak $SU(2)$ gauge and "Higgs" scalar fields. We assume the existence of a visible and an invisible (hidden) sector of the Universe. We used the extension of Plebanski's 4-dimensional gravitational…
The low energy effective theory of the N=1 supersymmetric SU(5) gauge theory with chiral superfields in the 5* and 10 representations is constructed. Instead of postulating the confinement of SU(5) (confining picture), only the confinement…