Related papers: Supergravity Solutions in the Low-$\tan\beta$ $ \l…
In grand unified theories (GUT) based on SO(10) all fermions of one generation are embedded in a single representation. As a result, the top quark, the bottom quark, and the $\tau$ lepton have a universal Yukawa coupling at the GUT scale.…
In supersymmetric theories with a strong conformal sector, soft supersymmetry breaking naturally gives rise to confinement and chiral symmetry breaking in the strong sector at the TeV scale. We construct and analyze models where such a…
The ansatz of vanishing A and B parameters eliminates CP violating complex phases in soft supersymmetry-breaking parameters of the minimal supersymmetric standard model, and thus provides a simple solution to the supersymmetry CP problem.…
We have studied the reconstruction of supersymmetric theories at high scales by evolving the fundamental parameters from the electroweak scale upwards. Universal minimal supergravity and gauge mediated supersymmetry breaking have been taken…
The Electroweak sector in E6 supersymmetric models is subject to a degree of fine tuning in the percent to permil level. This can be attributed to the experimental limits on both the mass of the Z' boson associated with the extra U(1)'…
The recent discovery of the putative 125-GeV Higgs boson has motivated a number of attempts to reconcile its relatively large mass with the predictions of the minimal supersymmetric standard model (MSSM). Some approaches invoked large…
We explore some topics in the phenomenology of gauge-mediated SUSY-breaking scenarios having a large hierarchy of Higgs VEVs, $v_U/v_D = tan\beta \gg 1$. Some motivation for this scenario is first presented. We then use a systematic,…
A new solution to the requirement of two-loop finiteness of the soft supersymmetry breaking terms (SSB) parameters is found in Finite-Gauge-Yukawa unified theories. The new solution has the form of a sum rule for the relevant scalar masses,…
In minimal supergravity theories the soft supersymmetry breaking (SSB) parameters are universal (flavor blind) near the Planck scale. Nevertheless, one often assumes universality at the grand-unification scale $M_{G} \approx 10^{16}$ GeV…
It has recently been shown that the studies of strongly-interacting electroweak symmetry breaking (EWSB) at photon colliders, via photon splitting into $W$ pair followed by longitudinal $W$-boson scattering, could be possible. Here we…
In the Minimal Supersymmetric Standard Model (the MSSM), the electroweak symmetry is restored as supersymmetry-breaking terms are turned off. We describe a generic extension of the MSSM where the electroweak symmetry is broken in the…
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…
We discuss several aspects of state-of-the-art calculations of radiative electroweak symmetry breaking in supergravity models. These models have a five-dimensional parameter space in contrast with the 21-dimensional one of the MSSM. We…
We present a new mechanism for electroweak symmetry breaking (EWSB) based on a strong Yukawa dynamics. We consider an SU(2)_L x U(1)_Y gauge invariant model endowed with the usual Standard model fermion multiplets and with two massive…
We study analytically the general features of electroweak symmetry breaking in the context of the Minimal Supersymmetric Standard Model extended by one Higgs singlet. The exact analytical forms of the renormalization group evolutions of the…
The renormalization of the Minimal Supersymmetric Standard Model of electroweak interactions is presented to all orders of perturbation theory using the algebraic method. Special attention is directed to the issues of soft supersymmetry…
We study the electroweak phase transition in a supersymmetric version of the Standard Model, in which a gauge singlet superfield is added to the Higgs sector. We show that the order of the transition is determined by the trilinear soft…
The top-quark Yukawa infrared fixed-point solution of the renormalization group equations, with minimal supersymmetry and GUT unification, defines a low-energy spectrum of supersymmetric particle masses in terms of a few GUT-scale…
We study models in which supersymmetry breaking appears at an intermediate scale, M_in, below the GUT scale. That is, that the soft supersymmetry-breaking parameters of the MSSM are universal at M_in. We demand that the lightest neutralino…
We study, in the Minimal Supersymmetric Standard Model, the electroweak symmetry breaking conditions obtained from the one-loop effective potential. Novel model-independent lower and upper bounds on $\tan \beta$, involving the other free…