# Measurement of Neutrino Oscillation Parameters from Muon Neutrino Disappearance with an Off-axis Beam

Abstract : 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 $3.01 \times 10^{20}$ protons on target. In the absence of neutrino oscillations, $205 \pm 17$ (syst.) events are expected to be detected and only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum assuming three neutrino flavors, normal mass hierarchy and $\theta_{23}\leq \pi/4$ yields a best-fit mixing angle $\sin^2(2\theta_{23})=1.000$ and mass splitting $|\Delta m^2_{32}| =2.44 \times 10^{-3}$ eV$^2$/c$^4$. If $\theta_{23}\geq \pi/4$ is assumed, the best-fit mixing angle changes to $\sin^2(2\theta_{23})=0.999$ and the mass splitting remains unchanged.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00850184
Contributor : Dominique Girod Connect in order to contact the contributor
Submitted on : Monday, August 5, 2013 - 2:29:53 PM
Last modification on : Friday, September 10, 2021 - 1:50:10 PM

### Citation

K. Abe, D. Autiero, J. Marteau. Measurement of Neutrino Oscillation Parameters from Muon Neutrino Disappearance with an Off-axis Beam. Physical Review Letters, American Physical Society, 2013, 111, pp.211803. ⟨10.1103/PhysRevLett.111.211803⟩. ⟨in2p3-00850184⟩