Akira Konaka
TRIUMF Laboratory

 JHF-SuperK long baseline neutrino oscillation project

The tiny neutrino masses indicated by the neutrino
oscillations provide important clue of the physics
at the grand unification scale. CP violation in
neutrino oscillation provides natural explanation of
the baryon asymmetry in the universe (Leptogenesis).
The neutrino oscillations are established in solar
($U_{e2}$) and atmospheric ($U_{\mu 3}$) neutrinos,
and their mixing parameters and mass differences are
reasonably well determined. The next step is to measure
the three generation mixing angle ($U_{e3}$) and the
CP violation in the neutrino oscillations.
JHF-Kamioka project is the leading project in measuring
these parameters. A neutrino beam from a 50GeV-0.75MW proton
accelerator (JHF) in Japan will be sent to Super-Kamiokande
water \v{C}erenkov detector located 295km away. The first
phase of the project, which is expected to start in 2007,
is sensitive to $|U_{e3}|^2$ twenty times beyond the current
reactor (CHOOZ) upper limit. In the second phase, with an
upgraded 4MW accelerator and 1Mton Hyper-Kamiokande detector,
the experiment will be sensitive to CP violation phase down
to 10-20 degrees.
Canadian group has been involved in this project from
the very beginning. A letter of intent by an international
group, which consist of 139 physicists from 11 countries
and 51 institutions, has been submitted in January 2003.
The JHF accelerator is under construction and will be
commissioned in 2006. Neutrino experiment is the flagship
experiment of the JHF project. The budget approval of the
neutrino beamline is expected this year.