The Hyper-Kamiokande project aims to address the mysteries of the origin and evolution of the Universe’s matter as well as to confront theories of elementary particle unification. To realize these goals it will combine a high intensity neutrino beam from J-PARC with a new detector based upon precision neutrino experimental techniques developed in Japan and built to be approximately 10 times larger than Super-Kamiokande.
An international Hyper-Kamiokande proto-collaboration has been formed to carry out the experiment which consists of about 300 researchers from 15 countries. The Institute for Cosmic Ray Research of the University of Tokyo and the Institute of Particle and Nuclear Studies of the High Energy Accelerator Research Organization KEK have signed a MoU affirming cooperation in the Hyper-K project to review and develop the program.
The proto-collaboration has succeeded in developing new 50-cm PMTs with double single-photon-sensitivity and has re-optimised the detector configuration. The new detector design successfully reduces the total project cost while preserving compelling and strong physics cases. Hyper-K is built as a tank with 187 kiloton fiducial volume with about 40,000 50-cm PMTs giving 40% photo cathode coverage.
The Hyper-K and J-PARC neutrino beam measurement of neutrino oscillation is more likely to provide a 5-sigma discovery of CP violation than any other existing experiment. Hyper-K will also be the world leader for nucleon decays. The sensitivity to the partial lifetime of protons for the decay modes of p→e+π0 is expected to exceed 1035 years. This is the only known, realistic detector option capable of reaching such a sensitivity for the p→e+π0 mode. Finally, the astrophysical neutrino program involves precision measurement of solar neutrinos and their matter effects, high-statistical supernova burst and supernova relic neutrinos.
- Schematic view of Hyper-Kamiokande