Particle hunters complete the set at last

时间:2019-03-06 09:11:04166网络整理admin

By Tom Clarke IT’S called DONUT, and it has filled a stubborn hole in particle physics. The experiment, conducted with the help of a 15-metre-long detector at Fermilab near Chicago, has provided the first direct evidence of the existence of the tau neutrino, the last of the matter particles, or fermions, predicted by the standard model of fundamental particles. “This is a tremendous pioneering experiment,” says physicist Martin Perl, who received a Nobel prize for discovering the related tau lepton. According to the standard model,