Measurement of muon antineutrino oscillations with an accelerator-produced off-axis beam.

Journal article

T2K reports its first measurements of the parameters governing the disappearance of ν¯μ in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν¯μ beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν¯μ survival probability is expected to be minimal. Using a data set corresponding to 4.01×1020 protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin2(θ¯23)=0.45 and |Δm¯232|=2.51×10−3  eV2 with 68% confidence intervals of 0.38–0.64 and 2.26–2.80×10−3  eV2, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the νμ disappearance parameters measured by T2K.

Authors: Barr, G; Dewhurst, D; Dolan, S; Duffy, K; Jacob, A

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Physical Society
• Journal: Physical Review Letters
• Volume: 116
• Issue: 18
• Pages: 181801
• Publication date: 2016-05-01
• Acceptance date: 2016-03-12
• DOI: 10.1103/PhysRevLett.116.181801
• EISSN: 1079-7114
• ISSN: 0031-9007
• Pmid: 27203315
• Language: English
• Keywords: T2K Collaboration