Physicists can rest easy – the Standard Model of Particle Physics is still in effect. More than 100 MIT students and professors jammed into Room 35-225 on Wednesday, April 11, 2007, to hear the long-anticipated results of a particle detection experiment designed to produce evidence that would confirm or reject the model, which outlines the elements of particle physics. MIT postdoctoral associate Jocelyn Monroe, who worked on the experiment, revealed the results about half an hour into her talk: the experiment confirms the model’s prediction that there are only three types of neutrinos.
https://news.mit.edu/2007/neutrino