Takashi Kobayashi, Tsuyoshi Nakaya and Masato Shiozawa have been awarded the Yoji Totsuka Prize for their contributions to discovering oscillations from muon neutrinos to electron neutrinos. Takashi Kobayashi is a professor of physics at the High Energy Accelerator Research Organization (KEK) and is head of the Particle and Nuclear Physics Division at the Japan Proton Accelerator Research Complex (J-PARC). Tsuyoshi Nakaya is a professor of physics at Kyoto University and is a Spokesperson for T2K. Masato Shiozawa is a professor of physics at the Institute for Cosmic Ray Research, University of Tokyo and is a member of the T2K Analysis Steering Group.
The discovery of oscillations from muon neutrinos to electron neutrinos was announced by T2K in July 2013. T2K makes a beam of muon neutrinos in Tokai on the east coast of Japan, and began to take physics data in January 2010. It sends the neutrino beam 295 km to its far detector Super-Kamiokande in western Japan. By the time of the announcement, 28 candidate electron neutrino events had been seen in Super-Kamiokande. This is an extremely important discovery as it is the first time that an explicit appearance of a unique flavor of neutrino at a detection point has been unequivocally observed from a different flavor of neutrino at its production point. This discovery also enables us to pursue a discovery of charge-parity violation in the lepton sector that may provide us with a critical key in our understanding of the matter-antimatter asymmetry in the universe, one of the most profound mysteries in science.
The Yoji Totsuka Prize is awarded annually to researchers who make outstanding contributions to advances in the fields of neutrino and non-accelerator physics. It was established in 2009 to commemorate Professor Yoji Totsuka’s distinguished achievements in neutrino physics, including the discovery of neutrino oscillations in solar and atmospheric neutrinos.
Congratulations Kobayashi-san, Nakaya-san and Shiozawa-san !