Narrow Results

We derive the relation between the amplitudes of short-baseline appearance and disappearance oscillations in $3+N_s$ neutrino mixing schemes which is the origin of the appearance–disappearance tension that is found from the analysis of the existing data in any $3+N_s$ neutrino mixing scheme. We illustrate the power of the relation to reveal the appearance–disappearance tension in the cases of $3+1$ and $3+2$ mixing using the results of global fits of short-baseline neutrino oscillation data.

Quark-lepton symmetry invites consideration of the existence of sterile neutrinos. Long ago, we showed that this approach predicts large neutrino mixing amplitudes. Using a Weyl spinor approach, we show, in an analytic example, how this, and pseudo-Dirac pairing, can develop within a reduced rank version of the conventional see-saw mechanism, from small intrinsic mixing strengths. We show by numerical examples that mixing of active and sterile neutrinos can affect the structure of oscillations relevant to extraction of neutrino mixing parameters from neutrino oscillation data.

Quark-lepton symmetry invites consideration of the existence of sterile neutrinos. Long ago, we showed that this approach predicts large neutrino mixing amplitudes. Using a Weyl spinor approach, we show, in an analytic example, how this, and pseudo-Dirac pairing, can develop within a reduced rank version of the conventional see-saw mechanism, from small intrinsic mixing strengths. We show by numerical examples that mixing of active and sterile neutrinos can affect the structure of oscillations relevant to extraction of neutrino mixing parameters from neutrino oscillation data.