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Abstract: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 couplings up to the GUT scale and present experimental bounds on all sparticles, Higgs scalar and top quark. The full radiative corrections to the Higgs potential due to the top/stop sector are included. We find a lower limit on the gluino mass of 160 GeV, upper limits on the lightest neutral scalar Higgs mass dependent on m top and the size of the soft supersymmetry breaking terms, and the possibility of a Higgs scalar as light as 10 GeV, but with reduced couplings to the Z boson.

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Super)conformal many-body quantum mechanics with extended supersymmetry A generalization of super-Lie algebras is presented. It is then shown that all known examples of fractional supersymmetry can be understood in this formulation. However, the incorporation of three-dimensional fractional supersymmetry in this framework needs some care. The proposed solutions lead naturally to a formulation of a fractional supersymmetry starting from any representation D of any Lie algebra g. This involves taking the Fth-roots of D in an appropriate sense. A fractional supersymmetry in any space-time dimension is then possible. This formalism finally leads to an infinite dimensional extension of g, reducing to the centerless Virasoro algebra when gϭsl(2,R).

We consider a four dimensional space-time symmetry which is a non trivial extension of the Poincaré algebra, different from supersymmetry and not contradicting a priori the well-known no-go theorems. We investigate some field theoretical aspects of this new symmetry and construct invariant actions for non-interacting fermion and noninteracting boson multiplets. In the case of the bosonic multiplet, where two-form fields appear naturally, we find that this symmetry is compatible with a local U (1) gauge symmetry, only when the latter is gauge fixed by a 't Hooft-Feynman term.