Neutrino masses potentially need no new physics. They fit the SU(3) x SU(2) x U(1) symmetry of the standard model (they are the only dimension 5 operator that fits the symmetry). If we give up the t’Hooft principal that physical models need to be renormalizable (after all, its not true with GR or the standard model!) then of course neutrinos have mass.
Neutrino masses potentially need no new physics. They fit the SU(3) x SU(2) x U(1) symmetry of the standard model (they are the only dimension 5 operator that fits the symmetry). If we give up the t’Hooft principal that physical models need to be renormalizable (after all, its not true with GR or the standard model!) then of course neutrinos have mass.