Related papers: U(1)' Symmetry Breaking in Supersymmetric E6 Model…
We construct examples of single-sector supersymmetry breaking based on simple deformations of supersymmetric QCD with (weakly) gauged flavor group. These theories are calculable in a weakly coupled Seiberg dual description. In these models,…
We introduce the sequence of spontaneous symmetry breaking of a coupling between Pati-Salam and electroweak symmetries $SU(4)_{PS} \otimes SU(4)_{EW}$ in order to establish a mathematically consistent relation among the coupling constants…
We discuss radiative electroweak symmetry breaking with non-universal scalar masses at the GUT scale. Large $\tan\beta$ solutions are investigated in detail and it is shown that qualitatively new (as compared to the universal case)…
We present a Z_6 orbifold compactification of the E_8xE_8 heterotic string which leads to the (supersymmetric) Standard Model gauge group and matter content. The quarks and leptons appear as three 16-plets of SO(10), whereas the Higgs…
Supersymmetry solves the gauge hierarchy problem of the Standard Model if the masses of supersymmetric partners of the SM particles are close to the weak scale. In this thesis, we argue that the supersymmetric Standard Model, while avoiding…
We consider a model with four generations of standard model fermions propagating in an extra dimension with an AdS background metric. We show that if the zero modes of the fourth generation are highly localized towards the infrared brane,…
The Principle of Naturalness of small parameters of a theory is reviewed. While quantum field theories constructed from gauge fields and fermions only are natural, those containing elementary scalar fields are not. In particular the Higgs…
We construct extensions of the Standard Model in which the gauge symmetries and supersymmetry prevent the dangerously large effects that may potentially be induced in a supersymmetric standard model by Planck scale physics. These include…
We scan the complete parameter space of the supersymmetric standard model extended by a gauge singlet, which is compatible with the following constraints: universal soft supersymmetry breaking terms at the GUT scale, finite running Yukawa…
Electroweak symmetry breaking is explored in a two Higgs doublet model based on a six dimensional $SU(4)$ gauge-Higgs unification compactified on an orbifold $T^2/Z_2$. The remarkable property of this model is a prediction of realistic weak…
We show that the electroweak fine-tuning parameter \Delta_{\rm EW} derived from the well-known electroweak symmetry breaking condition written in terms of weak scale parameters leads to {\it a bound on fine-tuning in the MSSM} and explain…
We propose a new model of 5D $SU(3)\otimes U(1)_X$ gauge-Higgs unification with a successful electroweak symmetry breaking and a realistic Higgs boson mass. In our model, the representations of the fermions are very simple, the ${\bf 3},…
Relationships between gauge, conformal and discrete symmetries in particle physics are analysed. We study also the effect of the electroweak mixing on the cancellation of SU(2) anomalous actions. It is shown that the relation theta_{W} =…
Naturalness of electroweak symmetry breaking in weak scale supersymmetric theories may suggest the absence of the conventional supersymmetric desert. We present a simple, realistic framework for supersymmetry in which (most of) the virtues…
We describe a 4D U(1) lattice gauge theory with charged scalar $\phi$ and fermion $\chi$ matter fields ($\chi U \phi$ model). At sufficiently strong gauge coupling, the chiral symmetry is broken and the mass of the unconfined composite…
If there is an extra U(1) gauge symmetry broken at low energies, then it may be possible from the charges of the known quarks and leptons under this U(1) to make inferences about how much gauge unification occurs at high scales and about…
We investigate supersymmetric models where neither R-parity nor lepton number nor baryon number is imposed. The full high energy theory has an exact horizontal U(1) symmetry that is spontaneously broken. Quarks and Higgs fields carry…
Motivated by the intriguing discrepancies in $b\to s \ell\ell$ transitions, the fermion mass problem, and a desire to preserve the accidental symmetries of the Standard Model (SM), we extend the SM by an anomalous $U(1)_X$ gauge symmetry…
We present simple models of dynamical supersymmetry breaking with gauged U(1)_R symmetry. The minimal supersymmetric standard model and supersymmetric SU(5) GUT are considered as the visible sector. The anomaly cancellation conditions for…
A linear realization of a model of dynamical electroweak symmetry breaking describing additional heavy vector bosons is proposed. The model is a SU(2)_L x U(1) x SU(2)_L' x SU(2)_R' gauge theory, breaking at some high scale u to SU(2)_weak…