First Neutrino Seen at Super-K, 295km from the T2K Beam Origin at J-PARC

This is the first neutrino created at the J-PARC laboratory, and sent across from the eastern coast of Japan, that was seen by the Super-Kamiokande detector, 295km away.

The picture shows the inside of the Super-K experiment, which is a vertical cylinder, filled with water, 40 metres high and a kilometre underground. The band in the middle is the side of the unfolded cylinder, and the two black circles are the top and bottom. The coloured blobs show the particles of light that were seen by the photon detectors that cover the inside of the cylinder, and the colours depend on the time when the light arrived there.

The rings that you can see formed by the coloured blobs are from the "Sonic Booooum" of light that made by the the particles that are created by the neutrino in Super-K. There are three rings -- the first two are bright yellow and obvious, but there is another one hidden there....

This is another image, with light-blue rings superimposed on it showing where the computer thinks they are. Making sure that we catch all the rings and interpret them properly is really important to get the right results out of our experiment.

There will be more to come, and when we see them we'll learn more about neutrinos, which can in turn tell us more about how our Universe came to be. For now though, we're happy that all parts of the T2K experiment are now working, from the beam, through the "near detector" that we built at J-PARC, and of course Super-Kamiokande.

We done to everyone who has been working all these years on T2K, and may the physics commence!