Related papers: Upper bounds on supersymmetry breaking from gauge …
We analyse the phenomenological implications of a particular class of supersymmetric models with additional space-time dimensions below the unification scale. Assuming the unification of the gauge couplings and using a two-loop calculation…
We examine the electroweak breaking mechanism in the minimal supersymmetric standard model (MSSM) using the {\em complete} one-loop effective potential $V_1$. First, we study what is the region of the whole MSSM parameter space (i.e.…
Gauge coupling unification and the stability of the Higgs vacuum are among two of the cherished features of low-energy supersymmetric models. Putting aside questions of naturalness, supersymmetry might only be realised in nature at very…
We show that one of the ways of obtaining consistency between the idea of supersymmetric grand unification and an apparent low value of $\alpha_{strong}(M_Z)\simeq .11$ indicated by several low energy experiments is to have an intermediate…
We recalculate the two-loop beta functions for three gauge couplings taking into account all low energy threshold corrections in split supersymmetry (split-SUSY) which assumes a very high scalar mass scale M_S. We find that, in split-SUSY…
We study the problem of selecting between different mechanisms of supersymmetry breaking in the Minimal Supersymmetric Standard Model using current data. We evaluate the Bayesian evidence of four supersymmetry breaking scenarios: mSUGRA,…
We propose a new next-to-minimal supersymmetric standard model (NMSSM) which is on a six-dimensional spacetime compactified on a $T^2/Z_3$ orbifold. In this model, three gauge singlet fields $N, S_1$ and $S_2$ in addition to the minimal…
In the context of supersymmetric $SO(10)$ grand unified models, it is shown that the gauge symmetry breaking as well as a natural doublet--triplet splitting can be achieved with a minimal Higgs system consisting of a single adjoint and a…
We examine the Constrained Minimal Supersymmetric Standard Model (CMSSM) with an additional requirement of strict b - tau unification in the region of small tan(beta). We find that the parameter space becomes completely limited below about…
The scale at which supersymmetry (SUSY) breaks ($m_{s}$) is still unknown. The present article, following a top-down approach, endeavors to study the effect of varying $m_s$ on the radiative stability of the observational parameters…
We review various ways of obtaining consistency between the idea of supersymmetric grand unification and an apparent low value of $\alpha_s \sim 0.112$ indicated by several low energy experiments. We argue that to reconcile the low value of…
We examine gauge coupling unification and prediction for $\alpha_s (M_Z)$ in minimal flipped SU(5) with gauge-mediated supersymmetry breaking. We include threshold corrections at weak scale, messenger scale and unification scale, and…
Properties and experimental predictions of a broad class of supergravity grand unified models possessing an $SU(5)$-type proton decay and $R$ parity are described. Models of this type can be described in terms of four parameters at the Gut…
The unification of gauge couplings suggests that there is an underlying (supersymmetric) unification of the strong, electromagnetic and weak interactions. The prediction of the unification scale may be the first quantitative indication that…
The most important hint of physics beyond the Standard Model (SM) from the 1995 precision electroweak data is that the most precisely measured quantities, the total, leptonic and hadronic decay widths of the $Z$ and the effective weak…
We re-examine the one-loop renormalization group equations (RGEs) for the dimensionful parameters of the minimal supersymmetric Standard Model with broken supersymmetry, allowing for arbitrary flavour structure of the soft SUSY breaking…
The recent discovery of a Higgs boson by the LHC experiments has profound implications for supersymmetric models. In particular, in the context of restricted models, such as the supergravity-inspired constrained minimal supersymmetric…
While it is often stated that the notion of electroweak (EW) naturalness in supersymmetric models is subjective, fuzzy and model-dependent, here we argue the contrary: electroweak naturalness can be elevated to a {\it principle} which is…
We study models in which supersymmetry breaking appears at an intermediate scale, M_{in}, below the GUT scale. We assume that the soft supersymmetry-breaking parameters of the MSSM are universal at M_{in}, and analyze the morphology of the…
The stability of the predictions of two of the standard model parameters, $\alpha_3(M_Z)$ and $\sin^2 \theta(M_Z)$, in a $M_U \sim 4$ TeV unification model is examined. It is concluded that varying the unification scale between $M_U \simeq…