At a ceremony held in Silicon Valley on November 8, the Sudbury Neutrino Observatory (SNO), the Kamioka Liquid-scintillator Antineutrino Detector (KamLAND) and the Daya Bay Reactor Neutrino Experiment (Daya Bay) were among five neutrino experiments awarded the 2016 Breakthrough Prize in Fundamental Physics. All three were made possible by contributions from scientists and engineers at the US Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The other honored experiments were Super-Kamiokande (Super-K) and KEK-to-Kamioka/Tokai-to-Kamioka (K2K/T2K).
The Breakthrough Prizes honor advances in fundamental physics, life sciences and mathematics and were founded in 2012 by Sergey Brin and Anne Wojcicki, Jack Ma and Cathy Zhang, Yuri Milner and Julia Milner, and Mark Zuckerberg and Priscilla Chan. The $3 million prizes are the richest in their fields, often awarded to more than one activity in each category and acknowledging the contributions of their team members.
In 1998, Japan’s Super-K reported indirect evidence for oscillation. SNO provided the first direct evidence of flavor change, among neutrinos generated by nuclear fusion in the heart of our sun. KamLAND, observing antineutrinos from nuclear reactors, confirmed that the flavor-change mechanism is oscillation. Daya Bay discovered the surprisingly large value of the last unknown neutrino “mixing angle.”
The fifth winners of the physics prize, K2K and T2K, were accelerator experiments in Japan that sent beams of muon neutrinos hundreds of kilometers to the Super-K detector. In 2011, T2K hinted at the first observation of muon neutrinos oscillating to electron neutrinos. The March 2011 earthquake interrupted the search, but in 2013 the observation was firmly established.