Neutrino oscillations observation

The next big neutrino experiment is the T2K experiment in Japan.


The beamline at T2K

The beam is created by colliding a proton beam with a suitable target and collecting and focusing the pions into a decay volume. In the diagrams, the initial state is on the left and the final state is on the right.

T2K consists of three main components: a proton accelerator at J-PARC which produces the neutrino beam; a suite of near detectors at J-PARC which measure the properties of the neutrinos before they've had a chance to change flavour; and a far detector, Super-Kamiokande, which measures the neutrino properties 295 km later. Do they have exotic properties that can't be explained by the Standard Model?

  • What role do neutrinos have in the evolution of the Universe?

    The beam itself that will be used is the most intense artificial neutrino beam that has so far been constructed and it will be produced at the J-PARC facility on Japan's east coast. But remember that within each mass state there are different flavour states. Comparison of the numbers of electron and muon neutrinos detected in T2K allows the mixing angle to be measured.

    MicroBooNE has been operation for several years, while the much larger ICARUS detector is now being comissioned.

  • T2K: In this experiment, a neutrino beam from J-PARC, an accelerator facility on the east coast of Japan, is sent 295 km to the Super-Kamiokande detector. This distance is necessary for the "standard" neutrinos at an energy of ~600 MeV to exhibit their maximum neutrino oscillation effects.  This experiment first observed muon neutrino to electron neutrino oscillations, setting the groundwork for ongoing and future searches for CP violation in the form of an imbalance in the oscillation probabilities between this mode of neutrino oscillations and its antimatter counterpart.
  • DUNE: A future "long baseline" neutrino oscillation experiment where a new neutrino beam at Fermilab will send a muon (anti)neutrino beam to a set of large (~17 kt) detectors at the Sanford Underground Research Facility 1300 km away more than 1 km (1 mile) underground.

    This mixing means that each neutrino mass state is a mixture of the different flavour (weak) states, and vice versa. Or do they exhibit "CP violation", an asymmetry between matter and antimatter?

  • Is there a pattern in the fundamental parameters which relate the neutrino flavor and mass states that point to new symmetries or physics?
  • What is the pattern of neutrino masses and why are they so small, more than a million times smaller than the electron, the next lighest particle?

    They are called "short baseline" experiments, and look for neutrinos to oscillate at a distance of ~1 km with a ~1 GeV muon neutrino beam. The muon neutrino disappearance measurement from the original beam is made by comparing the flux and energy spectra at a near detector before oscillations, with that at the far detector, Super-Kamiokande, after oscillations.

    The beam then carries on through 150 m of rock, which stops the muons, leaving a pure neutrino beam. the Higgs mechanism)?

  • Are there additional species of neutrnos than those we know about? Two main neutrino oscillation measurements will be made at T2K: the disappearance of muon neutrinos from the original beam and the appearance of electron neutrinos.

    It developed into a major international collaboration with collaborators from 12 countries. The beam will be directed underground to the Super-Kamiokande detector some 295 km away.