A Simple Model of Direct Gauge Mediation of Metastable Supersymmetry Breaking

We construct a model of direct gauge mediation of metastable SUSY breaking by simply deforming the Intriligator, Seiberg and Shih model in terms of a dual meson superpotential mass term. No extra matter field is introduced. The deformation explicitly breaks a U(1)_R symmetry and a pseudo moduli have a nonzero VEV at one-loop. Our metastable SUSY breaking vacuum turns out to be sufficiently long-lived. By gauging a subgroup of flavor symmetry, our model can directly couple to the standard model, which leads to nonvanishing gaugino mass generation. It is also shown that our model can evade the Landau pole problem. We show the parameters in the SUSY breaking sector are phenomenologically constrained.Comment: 14 pages, 1 figure, Final version to appear in PR

Light Higgs Triplets in Extra Dimensions

We discuss the possibility that the Higgs triplet can be light (1TeV in the most interesting case) without contradictions with the proton stability %and the gauge coupling unification in the context of higher dimensional theory. The proton stability is ensured by the suppression of Yukawa coupling of the Higgs triplet to the matter through its small overlap of wave functions in extra dimensions. The light Higgs triplets might be detected in future collider experiments as an alternative signature of GUT instead of the proton decay. The gauge coupling unification can be preserved by introducing extra bulk matter fields.Comment: 10 pages, LaTeX, the version to appear in PL

Structure of split supersymmetry and simple models

We derive in detail a condition on the Higgs mass parameters that is necessary for the recently proposed ``split supersymmetry'' (split SUSY) scenario to provide a realistic magnitude of $\tan \beta$. The nature of this condition can be understood by showing how the Higgs sector of the minimal supersymmetric Standard Model reduces to that of the Standard Model in the heavy limit of the soft supersymmetry breaking Higgs mass parameters. Based on this condition, we present some simple supersymmetry breaking models that each provides a realistic split-SUSY mass spectrum, in accordance with the scale of the gravitino mass ($m_{3/2}$) in relation to those of the soft scalar mass ($\tilde{m}$) and the gaugino mass ($M_{1/2}$) employed in each, namely $m_{3/2} \geq \tilde{m}$, $\tilde{m} \geq m_{3/2} \geq M_{1/2}$ and $M_{1/2} \geq m_{3/2}$, respectively, with the relation $\tilde{m} \gg M_{1/2}$ of the split-SUSY mass spectrum.Comment: 11 page