Speaker
Description
Neutrinos are the the most elusive among the known elementary particles, and for this reasson remain one of the mysterious pieces of the Standard Model. Today we know that the three neutrino flavours mix with each other through a quantum interference effect known as neutrino oscillations.
Since the discovery of the neutrino oscillations, one of the most interesting questions has been whether neutrino oscillation violates CP symmetry, which has important implications for cosmological models. This is studied by observing the oscillation of accelerator-produced neutrinos and antineutrinos over long distances.
T2K (Tokai to Kamioka) is an experiment sited in Japan that studies the phenomenon of neutrino and anti-neutrino oscillation over a distance of 295 km. It is of crucial importance in T2K to characterize the unoscillated neutrino flux (close to the neutrino beam generation point) with a Near Detector. In particular, the near detector is needed to constrain cross section uncertainties in neutrino-nucleus interactions, which will be a limiting factor for the measurement of neutrino oscillation parameters. T2K recently upgraded its near Detector with the addition, among other detectors, of a 2-tonnes neutrino active target named "Super Fine-Grained Detector" (SuperFGD). The SuperFGD is composed of about two-million 1-cm optically isolated plastic scintillator cubes. Scintillation light from the cube is read out by about 56-thousand channels from three directions through wavelength-shifting fibers and photo sensors. It provides 3D track reconstruction, 4$\pi$ angular acceptance, calorimetry, and detection capability of neutrons and low energy protons. This contribution reports the construction and performances of the SuperFGD, as well as the first physics results.
