> The standard model does not describe the neutrinos. In the standard model neutrinos are massless particles, but in reality they are not.
That's a bit strong. The SM still makes good predictions for many processes involving neutrinos. We just know, since the discovery of neutrino masses, that the SM, or at least the original version of it (there are proposed mechanisms that can handle neutrino masses without modifying anything else in the SM, although they still have some issues), can only be an approximation regarding neutrinos. But the SM is pretty much considered an approximation (or, as it is usually termed, an effective field theory) anyway.
That's a bit strong. The SM still makes good predictions for many processes involving neutrinos. We just know, since the discovery of neutrino masses, that the SM, or at least the original version of it (there are proposed mechanisms that can handle neutrino masses without modifying anything else in the SM, although they still have some issues), can only be an approximation regarding neutrinos. But the SM is pretty much considered an approximation (or, as it is usually termed, an effective field theory) anyway.