T. Nakaya: K2K and T2K
Continuing the overview of experiments that won the 2016 breakthrough prize, which is the theme of this afternoon’s session at Neutel 2017, Tsuyoshi Nakaya gave an overview of the K2K and the K2K experiments.
K2K was proposed in 1995 and in 1999 already started its data taking. It produced an indication of neutrino oscillations in 2002, and in 2004 a measurement. Data taking was finished in 2005. A proton synchrotron was used to direct a beam of neutrinos to the Kamioka mine. Following it, the T2K experiment was started in 2004 and got its first neutrino beam in 2009. An observation of electron neutrino appearance was obtained by T2K in 2013, and a hint of neutrino CP violation was obtained last year.
Both experiments designs rely on a beam of muon neutrinos produced by a proton accelerator, to study the oscillation properties of neutrinos. A “near detector” with a 1-kton of water as a target complements the “far detector” (Super-Kamiokande) to improve the measurement of the oscillations and to reduce systematic uncertainties.
Besides the Breakthrough prize of January 2016, the Bruno Pontecorvo prize was assigned in 2016 to Nihikawa.