Determining See-Saw Parameters from Weak Scale Measurements?

The see-saw mechanism is a very attractive explanation for small neutrino masses. However, many free parameters are introduced at a high energy scale, so analyzing other consequences of this new physics is difficult without additional hypotheses, such as flavour symmetries. In this letter we show that it is possible to parametrize the high energy physics just in terms of quantities measurable (in principle) at low energies: the neutrino Yukawa matrix, ${\bf Y_\nu}$, and the right-handed Majorana mass matrix, ${\cal M}$, can be calculated from the light neutrino masses, the MNS matrix, and ${\bf Y^{\dagger}_\nu} {\bf Y_\nu}$, which enters into the left-handed slepton radiative corrections. This raises the interesting possibility of obtaining model-independent information about consequences of the see-saw mechanism, such as leptogenesis. Future experiments at neutrino factories and the LHC will be crucial to further constrain these low energy quantities and test the supersymmetric see-saw scenario.