S-K

Super-Kamiokande is the large* water Cherenkov detector. The construction was started in 1991 and the observation began on April 1st, 1996. The Super-Kamiokande is operated by an international collaboration of about 150 people and about 40 institutes from Japan, the United States, Korea, China, Poland, Spain, Canada, UK, Italy and France.

The Super-Kamiokande detector consists of a stainless-steel tank, 39.3m diameter and 41.4m tall, filled with 50,000 tons of ultra pure water. About 13,000 photo-multipliers are installed on the tank wall. The detector is located at 1,000 meter underground in the Kamioka-mine, Hida-city, Gifu, Japan.

One of the purposes of the Super-Kamiokande experiment is to reveal the neutrino properties through the observation of solar neutrinos, atmospheric neutrinos and man-made neutrinos. In 1998, from the observation of atmospheric neutrinos we discovered the neutrino oscillations which neutrinos are changing their types in flight. In 2001, solar neutrino oscillations were discovered by the observation of solar neutrinos. In 2011, the third neutrino oscillation mode was discovered by man-made neutrino observation.

The CP symmetry-violating effect in neutrino and antineutrino oscillations has a magnitude that depends on the Jarlskog invariant:

JCP,1= 1/8 cosθ13sin(2θ12)sin(2θ23)sin(2θ13)sinδCP

Source: Super-Kamiokande.

* In actuality is the World’s largest.