Tsuyoshi Nakaya and Masato Shiozawa Awarded the 6th Yoji Totsuka Prize

Tsuyoshi Nakaya
Masato Shiozawa

Two affiliate members of Kavli IPMU have been awarded the 6th Yoji Totsuka Prize: Tsuyoshi Nakaya, Professor at Kyoto University, and Masato Shiozawa, Professor at the Institute for Cosmic Ray Research (ICRR). They shared this prize with Takashi Kobayashi, a professor at the Institute of Particle and Nuclear Studies, High-Energy Accelerator Research Organization (KEK). They have taken a leading role in the T2K (Tokai to Kamioka) collaboration, which is conducting a long-baseline neutrino oscillation experiment.

The Yoji Totsuka Prize was established in 2009 to memorialize Prof. Yoji Totsuka’s outstanding achievements on neutrino physics, including the discovery of neutrino oscillations in atmospheric and solar neutrinos. The purpose of this prize is to recognize researchers with distinguished achievements in the fields of experimental and theoretical particle physics, especially in the area of neutrino and non-accelerator physics.

The three recipients were honored for “the observation of electron neutrino appearance in a muon neutrino beam”. In the T2K experiment, a muon neutrino beam produced at the Japan Proton Accelerator Research Complex (J-PARC), located in Tokai village, Ibaraki prefecture, was emitted toward the Super-Kamiokande detector underground in Kamioka, Gifu prefecture, which is 295km (185miles) from J-PARC. In July 2013, the T2K collaboration was the first to confirm that electron neutrinos appear in a muon neutrino beam. This discovery provides the final piece of the neutrino oscillation puzzle among the three generations, i.e., electron, muon, and tau neutrinos. Thus, this work contributes not only to the progress of the neutrino physics, but also to the whole of the particle physics.

“This discovery of electron neutrino appearance is the result by the whole T2K collaborators. I feel very happy that the result has received this recognition. We started the design of the T2K experiment with Prof. Yoji Totsuka and Prof. Koichiro Nishikawa in 1999. At the beginning of the T2K project, my experience conducting research with Prof. Totsuka formed the foundation of my career as a scientist. I am honored to share a prize named after Prof. Totsuka, whom I greatly respect,” said Nakaya.

Shiozawa also said “It is very exciting that the achievement of the T2K won this prize. I think that I have been very lucky because I participated in three discoveries of neutrino oscillations: atmospheric, solar, and this third type.”

The award ceremony will be held on March 21, 2015 at Koshiba Hall on the Hongo Campus of the University of Tokyo.

Related Links

T2K collaboration webpage