Speaker
Hiroyuki Sekiya
(University of Tokyo)
Description
Hyper-Kamiokande (Hyper-K) will be a next generation underground water Cherenkov detector with the total (fiducial) mass
of 0.99 (0.56) million metric tons, which is approximately 20 (25) times larger than that of Super-Kamiokande.
One of the main goals of Hyper-K is the study of CP asymmetry in the lepton sector using accelerator
neutrino and anti-neutrino beams. With a total exposure of 7.5 MW $\times$ 10$^7$ sec integrated proton beam power (corresponding to 1.56 $\times$ 10 $^{22}$ protons on target
with a 30 GeV proton beam) to a 2.5-degree off-axis neutrino beam produced by the J-PARC proton synchrotron, it is expected
that the CP phase $\delta_{\rm CP}$ can be determined to better than 19 degrees for all possible values of $\delta_{\rm CP}$, and CP
violation can be established with a statistical significance of 3$\sigma$ for 76$\%$ of the $\delta_{\rm CP}$ parameter space.
Hyper-K’s high statistics data sample of atmospheric neutrinos will allow us to extract the information on the mass hierarchy and the octant of $\theta_{23}$.
With a full 10 year duration of data taking, the significance for the mass hierarchy determination is expected to reach 3$\sigma$ or greater if $\sin^2\theta_{23} > 0.4$.
The scope of studies at Hyper-K also covers high precision measurements of solar neutrinos, observation of supernova neutrinos, and dark matter searches.
Author
Hiroyuki Sekiya
(University of Tokyo)
