Analytical Study of Non-Universality of the Soft Terms in the MSSM

We obtain general analytical forms for the solutions of the one-loop renormalization group equations in the top/bottom/$\tau$ sector of the MSSM. These solutions are valid for any value of $\tan \beta$ as well as any non-universal initial conditions for the soft SUSY breaking parameters and non-unification of the Yukawa couplings. We establish analytically a generic screening effect of non-universality, in the vicinity of the infrared quasi fixed point, which allows to determine sector-wise a hierarchy of sensitivity to initial conditions. We give also various numerical illustrations of this effect away from the quasi fixed point and assess the sensitivity of the Higgs and sfermion spectra to the non-universality of the various soft breaking sectors. As a by-product, a typical anomaly-mediated non-universality of the gaugino sector would have marginal influence on the scalar spectrum