The Tokai to Kamioka (T2K) long-baseline neutrino experiment consists of a muon neutrino beam, produced at the J-PARC accelerator, a near detector complex and a large 295-km-distant far detector. The present work utilizes the T2K event timing measurements at the near and far detectors to study neutrino time of flight as a function of derived neutrino energy. Under the assumption of a relativistic relation between energy and time of flight, constraints on the neutrino rest mass can be derived. The sub-GeV neutrino beam in conjunction with timing precision of order tens of ns provide sensitivity to neutrino mass in the few MeV/c2 range. We study the distribution of relative arrival times of muon and electron neutrino candidate events at the T2K far detector as a function of neutrino energy. The 90% C.L. upper limit on the mixture of neutrino mass eigenstates represented in the data sample is found to be mν2<5.6 MeV2/c4.
Publication Source (Journal or Book title)
Physical Review D
Abe, K., Adam, J., Aihara, H., Akiri, T., Andreopoulos, C., Aoki, S., Ariga, A., Assylbekov, S., Autiero, D., Barbi, M., Barker, G., Barr, G., Bartet-Friburg, P., Bass, M., Batkiewicz, M., Bay, F., Berardi, V., Berger, B., Berkman, S., Bhadra, S., Blaszczyk, F., Blondel, A., Bojechko, C., Bolognesi, S., Bordoni, S., Boyd, S., Brailsford, D., & Bravar, A. (2016). Upper bound on neutrino mass based on T2K neutrino timing measurements. Physical Review D, 93 (1) https://doi.org/10.1103/PhysRevD.93.012006