be good for most of the set of parameters that will be selected on a phenomenological basis. However, for the sake of precision, we numerically integrate the RGE in our analysis, the expressions in the Appendix being reserved for analytical discussions of the numerical results. In practice, we renormalize the parameters down to the scale $v$ through the supersymmetric RGE, and then apply the Coleman-Weinberg corrections to the Higgs potential to take into account the decoupling of the stops at $M_{\mathrm{susy}}$.

The important hypothesis to be made in this paper is the so-called “universality” or flavour-independence for the soft-terms in (\[B\]). For the supersymmetry breaking scalar interactions it amounts to assume a common value for all the parameters $A_{i}$ in (\[B\]) $\mathrm{(at\ }%
\Lambda _{\mathrm{GUT}}\mathrm{)},$

$$A_{\lambda }=A_{\kappa }=A_{t}=A_{b}=A_{\tau }=...=A_0,  \label{C}$$

and the same values (at $\Lambda_{\mathrm{GUT}}$) for the scalar masses in (\[B\]),

$$m_{1}^{2}=m_{2}^{2}=m_{S}^{2}=m_{Q_3}^{2}=m_{T}^{2}=...=m_0^2.  \label{D}$$

This universality follows if the direction of supersymmetry breaking, characterized by the goldstino components, corresponds to fields with purely gravitational couplings to the relevant chiral superfields (for instance, if it is along the dilaton-axion direction in superstring inspired theories [@BFS]). Of course, it follows in general if the goldstino components have equal couplings to all relevant 