A supersimple analysis of $e^-e^+\to t \bar t$ at high energy
  According to supersimplicity in MSSM, a renormalization scheme (SRS) may be defined for any high energy 2-to-2 process, to the 1loop EW order; where the helicity conserving (HC) amplitudes, are expressed as a linear combination of just three universal logarithm-involving forms.   All other helicity amplitudes vanish asymptotically. Including to these SRS amplitudes the corresponding counter terms, the "supersimple" expressions for the high energy HC amplitudes, renormalized on-shell, are obtained.   Previously, this property was noted for a large number of processes that do not involve Yukawa interactions or renormalization group corrections. Here we extend it to $e^-e^+\to t \bar t$, which does involve large Yukawa and renormalization group contributions. We show that the resulting "supersimple" expressions may provide an accurate description, even at energies comparable to the SUSY scale. Such descriptions clearly identify the origin of the important SUSY effects, and they may be used for quickly constraining physics contributions, beyond MSSM. 
G. J. Gounaris and F. M. Renard
hep-ph