2013/08/31 by T2K collaboration, K. Abe, J. Adam +350 · 3 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Energy (signal processing) #Measurements of neutrino speed #Mixing (physics) #Muon #Muon neutrino #Neutrino #Neutrino Physics Research #Neutrino detector #Neutrino oscillation #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Solar neutrino #Solar neutrino problem #hep-ex
paper · pdf · doi:10.1103/physrevlett.111.211803
published as Phys. Rev. Lett. 111, 211803 (2013) · 8 pages, 4 figures, revised version accepted for publication in Physical Review Letters
arxiv created 2013/10/14 · openalex publication_date 2013/11/19 · arxiv updated 2013/11/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01\ifmmode×\else\texttimes\fi1020 protons on target. In the absence of neutrino oscillations, 205\ifmmode±\else\textpm\fi17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(\ensuremathθ23)=0.514\ifmmode±\else\textpm\fi0.082 and mass splitting |\ensuremathΔm322|=2.44_\ensuremath-0.15+0.17\ifmmode×\else\texttimes\fi10^\ensuremath-3 eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.