PT Journal
AU T2K Collaboration (Abe, Kea
   Cervera-Villanueva, A
   Escudero, L
   Gomez-Cadenas, JJ
   Hansen, C
   Monfregola, L
   Sorel, M
   Stamoulis, P
TI First muon-neutrino disappearance study with an off-axis beam
SO Physical Review D
JI Phys. Rev. D
PY 2012
BP 031103
EP 8pp
VL 85
IS 3
DI 10.1103/PhysRevD.85.031103
LA English
AB We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 x 10(20) protons on target, we observe 31 fully-contained single mu-like ring events in Super-Kamiokande, compared with an expectation of 104 +/- 14 (syst) events without neutrino oscillations. The best-fit point for two-flavor nu(mu) -> nu(tau) oscillations is sin(2)(2 theta(23)) = 0.98 and vertical bar Delta m(32)(2)vertical bar = 2.65 x 10(-3) eV(2). The boundary of the 90% confidence region includes the points sin(2)(2 theta(23)), vertical bar Delta m(32)(2)vertical bar = (1.0, 3.1 x 10(-3) eV(2)), (0.84, 2.65 x 10(-3) eV(2)) and (1.0, 2.2 x 10(-3) eV(2)).
ER