Higgs exempt no-scale supersymmetry

Models with acceptably small flavor changing neutral currents at the low scale require highly constrained scalar masses at the high scale. With all boundary masses small except the gauginos and Higgs bosons, the renormalization group running will induce nearly diagonal soft masses. These diagonal soft masses in Higgs exempt no-scale supersymmetry (HENS) lead to minimal amounts of flavor violation. Possible mechanisms for producing the HENS boundary conditions are discussed: no-scale supersymmetry, gaugino mediated supersymmetry breaking, and conformal sequestering. The parameter space of HENS models is constrained by considerations of radiative electroweak symmetry breaking, superpartner masses, and flavor violation. Dark matter constraints are examined as well as key collider signals. HENS models, unlike pure no-scale models, have a neutralino lightest superpartner that is a candidate for thermal dark matter. The light slepton masses give a distinctive set of lepton signatures including a relatively large 4ℓ signal. By extending the HENS model to include right-handed neutrinos, it is able to accommodate neutrino oscillation experiments. Right-handed neutrinos also tend to introduce new sources of lepton flavor violation. However, they can also explain the baryon asymmetry via leptogenesis. The interplay of these considerations places restrictions on the neutrino Yukawa couplings. In HENS type models, large negative Higgs masses and light sleptons can lead to unbounded from below directions. Requiring that the SM vacuum be stable for the lifetime of the universe further constrains the parameter space of the HENS model. For large tan beta ≳ 30 little of the parameter space with a neutralino LSP remains.