Effects of new physics in neutrino oscillations in matter

A new flavour-changing electron neutrino interaction with matter would always dominate the nu(e) oscillation probability at sufficiently high neutrino energies. Being suppressed by theta(13), the energy scale at which the new effect starts to be relevant may be within the reach of realistic experiments, where the peculiar dependence of the signal with energy could give rise to a clear signature in the nu(e) --> nu(tau) channel. The latter could be observed by means of a coarse large magnetized detector exploiting tau --> mu decays. We discuss the possibility of identifying or constraining such effects with a high energy neutrino factory. We also comment on the model-independent limits on them.