155 research outputs found

    Effects of new physics to the the ρ\rho--parameter in the supersymmetric standard model

    Full text link
    The contribution to the ρ\rho--parameter of the quark--Higgs sector of the supersymmetric standard model is computed non--perturbatively using the large--\nf expansion for the case tanβ\beta=0. An explicit formula is found for the ρ\rho--parameter which is ill-defined unless the triviality cutoff is taken into account. The cutoff dependence of the ρ\rho--parameter is found to be large if and only if the top mass is larger than 2v2v so that the cutoff scale is of the order of the electroweak scale. These non--universal effects are the reflections at low energies of the physics beyond the supersymmetric standard model. By also considering the effects of the soft--breaking terms, cutoff effects in both decoupling and non--decoupling effects are analyzed.Comment: 12 pages (5 figs), TIT/HEP-233, harvma

    Some thermal transport properties of the FPU model with quadratic pinning

    Full text link
    Thermal transport properties of the FPU β\beta model with a quadratic pinning term are investigated for various couplings and temperatures. In particular, the size dependence of the thermal conductivity, κLα\kappa\propto L^\alpha, is studied. α\alpha agrees with that of the FPU β\beta model (with no pinning) at high temperatures but decreases at low temperatures. This crossover behavior occurs at a temperature depending on the strength of the quadratic pinning.Comment: 10pages, 4 fig