2011/12/01 by Izmaylov, Alexander
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)
paper · doi:10.48550/arxiv.1112.0273
The T2K (Tokai to Kamioka) experiment is a second generation long baseline neutrino oscillation experiment located in Japan. The main goal is to probe the θ13 neutrino mixing parameter by looking for νμ→νe transitions in an almost pure beam of muon neutrinos. The T2K utilizes the neutirno beam produced at J-PARC (Tokai, Ibaraki) and Super-Kamiokande (Kamioka, Gifu) is used as a far detector. The experiment has been in operation since January 2010. After analyzing 1.43×1020 p.o.t. data collected six events are observed in far detector while the expected number with sin2 2θ13=0 is 1.5±0.3. Null oscillation hypotheis leads to 7×10-3 probability to observe six or more candidate events, which so gives 2.5 σ significance to the result. Thus the current T2K result is an indication of νe appearance due to νμ→νe transitions. As for the first T2K νμ disappearance data, the null oscillation hypothesis is exluded at 4.5 σ level and the estimated atmospheric mixing parameters are consistent with the results from Super-Kamiokande and MINOS experiments.