Discriminating sterile neutrinos and unitarity violation with CP   invariants
  We present a new method to analyze upcoming results in the search for CP violating neutrino oscillations. The CP violating amplitudes $\mathcal{A}_{\alpha\beta}^{kj}$ provide parametrization independent observables, which will be accessible by experiments soon. The strong prediction of a unique $\mathcal{A}_{\alpha\beta}^{kj}$ (the Jarlskog invariant) in case of the standard three neutrino model does not hold in models with new physics beyond the Standard Model. Nevertheless there are still correlations among the amplitudes depending on the specific model. Due to these correlations it is possible to reject specific new physics models by determining only 3 of the CP violating amplitudes. 
Heinrich P\"as, Philipp Sicking
hep-ph