A High-energy determination of Yukawa couplings in SUSY models

We consider the production, at future lepton colliders, of final fermion, sfermion, scalar pairs in SUSY models. For third family fermions and sfermions and for charged Higgses, the leading Yukawa effect at one loop for large c.m. energies comes from a linear logarithm of Sudakov type, that only depends, in the MSSM, on one SUSY mass scale and on $\tan(\beta)$. Assuming a relatively light SUSY scenario, we illustrate a possible determination of $\tan(\beta)$ at c.m. energies of about 1 TeV, working systematically at subleading logarithmic accuracy, at the one-loop level.