Disappearing Neutrinos Support the Case for Neutrino Mass

Results from the first six months of experiments at KamLAND, an underground neutrino detector in central Japan, show that anti-neutrinos emanating from nearby nuclear reactors are “disappearing,” which indicates they have mass and can oscillate or change from one type to another. As anti-neutrinos are the anti-matter counterpart to neutrinos, these results provide independent confirmation of earlier studies involving solar neutrinos and show that the Standard Model of Particle Physics, which has successfully explained fundamental physics since the 1970’s, is in need of updating. The results also point the way to the first direct measurements of the total radioactivity of the earth.