-
Collaboration,
K. Abe,
N. Abgrall,
H. Aihara,
T. Akiri,
J. B. Albert,
C. Andreopoulos,
S. Aoki,
A. Ariga,
T. Ariga, [......],
N. Yershov,
M. Yokoyama,
T. Yuan,
A. Zalewska,
L. Zambelli,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an
off-axis muon neutrino beam with a peak energy of about 0.6 GeV that originates
at the J-PARC accelerator facility. Interactions of the neutrinos are observed
at near detectors placed at 280 m from the production target and at the far
detector -- Super-Kamiokande (SK) -- located 295 km away. The flux prediction
is an essential part of the successful prediction of neutrino interaction rates
at the T2K detectors and is an important input to T2K neutrino oscillation and
cross section measurements. A FLUKA and GEANT3 based simulation models the
physical processes involved in the neutrino production, from the interaction of
primary beam protons in the T2K target, to the decay of hadrons and muons that
produce neutrinos. The simulation uses proton beam monitor measurements as
inputs. The modeling of hadronic interactions is re-weighted using thin target
hadron production data, including recent charged pion and kaon measurements
from the NA61/SHINE experiment. For the first T2K analyses the uncertainties on
the flux prediction are evaluated to be below 15% near the flux peak. The
uncertainty on the ratio of the flux predictions at the far and near detectors
is less than 2% near the flux peak.
11/2012;
-
C. Regis,
K. Abe,
Y. Hayato,
K. Iyogi,
J. Kameda,
Y. Koshio,
Ll. Marti,
M. Miura,
S. Moriyama,
M. Nakahata, [......],
M. Yokoyama,
K. Martens,
M. R. Vagins,
S. Chen,
H. Sui,
Z. Yang,
H. Zhang,
K. Connolly,
M. Dziomba,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: We have searched for proton decay via p→μ+K0 using data from a 91.7 kiloton·year exposure of Super-Kamiokande- I, a 49.2 kiloton·year exposure of Super-Kamiokande II, and a 31.9 kiloton·year exposure of Super-Kamiokande III. The number of candidate events in the data was consistent with the atmospheric neutrino background expectation and no evidence for proton decay in this mode was found. We set a partial lifetime lower limit of 1.6×1033 years at the 90% confidence level.
Phys. Rev. D. 07/2012; 86(1).
-
H. Nishino,
K. Abe,
Y. Hayato,
T. Iida,
M. Ikeda,
J. Kameda,
Y. Koshio,
M. Miura,
S. Moriyama,
M. Nakahata, [......],
M. R. Vagins,
S. Chen,
Y. Heng,
J. Liu,
Z. Yang,
H. Zhang,
D. Kielczewska,
K. Connolly,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: Searches for a nucleon decay into a charged antilepton (e+ or μ+) plus a light meson (π0, π-, η, ρ0, ρ-, ω) were performed using the Super-Kamiokande I and II data. Twelve nucleon decay modes were searched for. The total exposure is 140.9 kiloton·years, which includes a 91.7 kiloton·year exposure (1489.2 live days) of Super-Kamiokande-I and a 49.2 kiloton·year exposure (798.6 live days) of Super-Kamiokande II. The number of candidate events in the data was consistent with the atmospheric neutrino background expectation. No significant evidence for a nucleon decay was observed in the data. Thus, lower limits on the nucleon partial lifetime at 90% confidence level were obtained. The limits range from 3.6×1031 to 8.2×1033 years, depending on the decay modes.
Phys. Rev. D. 06/2012; 85(11).
-
The Super-Kamiokande Collaboration: C. Regis,
K. Abe,
Y. Hayato,
K. Iyogi,
J. Kameda,
Y. Koshio,
Ll. Marti,
M. Miura,
S. Moriyama,
M. Nakahata, [......],
M. Yokoyama,
K. Martens,
M. R. Vagins,
S. Chen,
H. Sui,
Z. Yang,
H. Zhang,
K. Connolly,
M. Dziomba,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: We have searched for proton into muon plus neutral kaon using data from a
91.7 kiloton-year exposure of Super-Kamiokande-I, a 49.2 kiloton-year exposure
of Super-Kamiokande-II, and a 31.9 kiloton-year exposure of
Super-Kamiokande-III. The number of candidate events in the data was consistent
with the atmospheric neutrino background expectation and no evidence for proton
decay in this mode was found. We set a partial lifetime lower limit of
1.6x10^33 years at the 90% confidence level.
05/2012;
-
Super-Kamiokande Collaboration: H. Nishino,
K. Abe,
Y. Hayato,
T. Iida,
M. Ikeda,
J. Kameda,
Y. Koshio,
M. Miura,
S. Moriyama,
M. Nakahata, [......],
M. R. Vagins,
S. Chen,
Y. Heng,
J. Liu,
Z. Yang,
H. Zhang,
D. Kielczewska,
K. Connolly,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: Searches for a nucleon decay into a charged anti-lepton (e^+ or {\mu}^+) plus
a light meson ({\pi}^0, {\pi}^-, {\eta}, {\rho}^0, {\rho}^-, {\omega}) were
performed using the Super-Kamiokande I and II data. Twelve nucleon decay modes
were searched for. The total exposure is 140.9 kiloton \cdot years, which
includes a 91.7 kiloton \cdot year exposure (1489.2 live days) of
Super-Kamiokande-I and a 49.2 kiloton \cdot year exposure (798.6 live days) of
Super-Kamiokande-II. The number of candidate events in the data was consistent
with the atmospheric neutrino background expectation. No significant evidence
for a nucleon decay was observed in the data. Thus, lower limits on the nucleon
partial lifetime at 90% confidence level were obtained. The limits range from
3.6 \times 10^31 to 8.2 \times 10^33 years, depending on the decay modes.
03/2012;
-
The Super-Kamiokande Collaboration: K. Ueno,
K. Abe,
Y. Hayato,
T. Iida,
K. Iyogi,
J. Kameda,
Y. Koshio,
Y. Kozuma,
M. Miura,
S. Moriyama, [......],
S. Chen,
Y. Heng,
Z. Yang,
H. Zhang,
D. Kielczewska,
P. Mijakowski,
K. Connolly,
M. Dziomba,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: GUT monopoles captured by the Sun's gravitation are expected to catalyze
proton decays via the Callan-Rubakov process. In this scenario, protons, which
initially decay into pions, will ultimately produce \nu_{e}, \nu_{\mu} and
\bar{\nu}_{\mu}. After undergoing neutrino oscillation, all neutrino species
appear when they arrive at the Earth, and can be detected by a 50,000 metric
ton water Cherenkov detector, Super-Kamiokande (SK). A search for low energy
neutrinos in the electron total energy range from 19 to 55 MeV was carried out
with SK and gives a monopole flux limit of F_M(\sigma_0/1 mb) < 6.3 \times
10^{-24} (\beta_M/10^{-3})^2 cm^{-2} s^{-1} sr^{-1} at 90% C.L., where \beta_M
is the monopole velocity in units of the speed of light and \sigma_0 is the
catalysis cross section at \beta_M=1. The obtained limit is more than eight
orders of magnitude more stringent than the current best cosmic-ray
supermassive monopole flux limit, F_M < 1 \times 10^{-15} cm^{-2} s^{-1}
sr^{-1} for \beta_M < 10^{-3} and also two orders of magnitude lower than the
result of the Kamiokande experiment, which used a similar detection method.
03/2012;
-
Collaboration,
K. Abe,
N. Abgrall,
Y. Ajima,
H. Aihara,
J. B. Albert,
C. Andreopoulos,
B. Andrieu,
M. D. Anerella,
S. Aoki, [......],
M. Yokoyama,
T. Yuan,
A. Zalewska,
J. Zalipska,
L. Zambelli,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: 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 10**20 protons on target, we observe 31
fully-contained single muon-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 |\Delta m**2_32| = 2.65 10**-3 eV**2. The boundary of the
90 % confidence region includes the points (sin**2(2 theta_23),|\Delta
m**2_32|) = (1.0, 3.1 10**-3 eV**2), (0.84, 2.65 10**-3 eV**2) and (1.0, 2.2
10**-3 eV**2).
01/2012;
-
K Abe,
Y Hayato,
T Iida,
M Ikeda,
K Iyogi,
J Kameda,
Y Koshio,
Y Kozuma,
M Miura,
S Moriyama, [......], Y Totsuka,
S Chen,
Y Heng,
Z Yang,
H Zhang,
D Kielczewska,
P Mijakowski,
K Connolly,
M Dziomba,
R J Wilkes
[show abstract]
[hide abstract]
ABSTRACT: We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande-I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best-fit antineutrino mixing is found to be at (Δm2,sin2 2θ)=(2.0×10(-3) eV2, 1.0) and is consistent with the overall Super-K measurement.
Physical Review Letters 12/2011; 107(24):241801. · 7.37 Impact Factor
-
The Super-Kamiokande Collaboration: K. Bays,
T. Iida,
K. Abe,
Y. Hayato,
K. Iyogi,
J. Kameda,
Y. Koshio,
L. Marti,
M. Miura,
S. Moriyama, [......], Y. Totsuka,
M. Yokoyama,
Y. Heng,
S. Chen,
H. Zhang,
Z. Yang,
P. Mijakowski,
K. Connolly,
M. Dziomba,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: A new Super-Kamiokande (SK) search for Supernova Relic Neutrinos (SRNs) was
conducted using 2853 live days of data. Sensitivity is now greatly improved
compared to the 2003 SK result, which placed a flux limit near many theoretical
predictions. This more detailed analysis includes a variety of improvements
such as increased efficiency, a lower energy threshold, and an expanded data
set. New combined upper limits on SRN flux are between 2.8 and 3.0 nu_e cm^-2
s^-1 > 16 MeV total positron energy (17.3 MeV E_nu).
11/2011;
-
K Abe,
N. Abgrall,
Y. Ajima,
H. Aihara,
J. B. Albert,
C. Andreopoulos,
B Andrieu,
M. D. Anerella,
S Aoki,
O. Araoka, [......],
M Yokoyama,
T Yuan,
A Zalewska,
J. Zalipska,
L. Zambelli,
K Zaremba,
M Ziembicki,
E. D. Zimmerman,
M Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: Precise measurement of neutrino beam direction and intensity was achieved
based on a new concept with modularized neutrino detectors. INGRID (Interactive
Neutrino GRID) is an on-axis near detector for the T2K long baseline neutrino
oscillation experiment. INGRID consists of 16 identical modules arranged in
horizontal and vertical arrays around the beam center. The module has a
sandwich structure of iron target plates and scintillator trackers. INGRID
directly monitors the muon neutrino beam profile center and intensity using the
number of observed neutrino events in each module. The neutrino beam direction
is measured with accuracy better than 0.4 mrad from the measured profile
center. The normalized event rate is measured with 4% precision.
11/2011;
-
T. Tanaka,
K. Abe,
Y. Hayato,
T. Iida,
J. Kameda,
Y. Koshio,
Y. Kouzuma,
M. Miura,
S. Moriyama,
M. Nakahata, [......],
Y. Heng,
Z. Yang,
H. Zhang,
D. Kielczewska,
P. Mijakowski,
K. Connolly,
M. Dziomba,
E. Thrane,
R. J. Wilkes,
and (The Super-Kamiokande Collaboration
[show abstract]
[hide abstract]
ABSTRACT: We present the result of an indirect search for high energy neutrinos from Weakly Interacting Massive Particle (WIMP) annihilation in the Sun using upward-going muon (upmu) events at Super-Kamiokande. Data sets from SKI-SKIII (3109.6 days) were used for the analysis. We looked for an excess of neutrino signal from the Sun as compared with the expected atmospheric neutrino background in three upmu categories: stopping, non-showering, and showering. No significant excess was observed. The 90% C.L. upper limits of upmu flux induced by WIMPs of 100 GeV c-2 were 6.4 × 10–15 cm–2 s–1 and 4.0 × 10–15 cm–2 s–1 for the soft and hard annihilation channels, respectively. These limits correspond to upper limits of 4.5 × 10–39 cm–2 and 2.7 × 10–40 cm–2 for spin-dependent WIMP-nucleon scattering cross sections in the soft and hard annihilation channels, respectively.
The Astrophysical Journal 11/2011; 742(2):78. · 6.02 Impact Factor
-
J Onishi,
H Baba,
M Ikeda,
H Kawamura,
R Kishi,
Y Nakaya,
K Ninomiya,
N Ogawa,
R Openshaw,
M Pearson,
E Seitaibashi, Y Totsuka,
T Toyoda,
M Uchida,
J Murata
[show abstract]
[hide abstract]
ABSTRACT: A new experimental project called MTV(Mott Polarimetry for T-Violation Experiment)-S1183 has started at TRIUMF, aiming to achieve the highest precision test of time reversal symmetry in polarized nuclear beta decay. In this experiment, existence of T-violating transverse polarization of electrons emitted from polarized nuclei is examined, using a multi-wire drift chamber (MWDC) as an electron tracking detector in order to measure Mott scattering asymmetries. In this paper, technical aspects of the electron polarimetry are described. The Mott polarimeter, MWDC, consists of six sense layers. In order to improve the real backward scattering event purity, a new intelligent triggering system using FPGA module to perform on-line hit pattern recognition was developed. The new triggering system was installed for the first commissioning experiment in November 2009 at TRIUMF-ISAC. In addition to the triggering system, a new buffering DAQ system was also developed in order to achieve the needed high triggering rate at ISAC. Details of their performance are also described.
Journal of Physics Conference Series 09/2011; 312(10):102012.
-
Super-Kamiokande Collaboration: K. Abe,
Y. Hayato,
T Iida,
K Ishihara,
J. Kameda,
Y. Koshio,
A. Minamino,
C. Mitsuda,
M Miura,
S Moriyama, [......], Y Totsuka,
S Chen,
Z Deng,
Y Liu,
D. Kielczewska,
H. G. Berns,
K. K. Shiraishi,
E. Thrane,
K. Washburn,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: A search for neutron-antineutron (n - nbar) oscillation, a process with
|\DeltaB| = 2 that has been predicted by right-left (R-L) symmetric gauge
theories, was undertaken using the 24.5\times10^33 neutron-yrs exposure of
Super- Kamiokande I, in an analysis that included the significant sources of
experimental uncertainties. No evidence for n - nbar oscillation was found, the
lower limit of the lifetime for neutrons bound in ^16 O was determined to be
1.89 \times 10^32 yrs at the 90% confidence level (C.L.), and the corresponding
limit for the oscillation time for free neutrons was calculated to be 2.44
\times 10^8 sec using a theoretical suppression factor of 1.0 \times 10^23
sec^-1.
09/2011;
-
G. Mitsuka,
K Abe,
Y. Hayato,
T Iida,
M Ikeda,
J. Kameda,
Y. Koshio,
M Miura,
S Moriyama,
M Nakahata, [......], Y Totsuka,
S Chen,
J Liu,
Y. Heng,
Z Yang,
H Zhang,
D. Kielczewska,
K Connolly,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: In this paper we study non-standard neutrino interactions as an example of
physics beyond the standard model using atmospheric neutrino data collected
during the Super-Kamiokande I(1996-2001) and II(2003-2005) periods. We focus on
flavor-changing-neutral-currents (FCNC), which allow neutrino flavor
transitions via neutral current interactions, and effects which violate lepton
non-universality (NU) and give rise to different neutral-current
interaction-amplitudes for different neutrino flavors. We obtain a limit on the
FCNC coupling parameter, varepsilon_{mu tau}, |varepsilon_{mu tau}|<1.1 x
10^{-2} at 90%C.L. and various constraints on other FCNC parameters as a
function of the NU coupling, varepsilon_{e e}. We find no evidence of
non-standard neutrino interactions in the Super-Kamiokande atmospheric data.
09/2011;
-
The Super-Kamiokande Collaboration: T. Tanaka,
K. Abe,
Y. Hayato,
T. Iida,
J. Kameda,
Y. Koshio,
Y. Kouzuma,
M. Miura,
S. Moriyama,
M. Nakahata, [......],
S. Chen,
Y. Heng,
Z. Yang,
H. Zhang,
D. Kielczewska,
P. Mijakowski,
K. Connolly,
M. Dziomba,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: We present the result of an indirect search for high energy neutrinos from
WIMP annihilation in the Sun using upward-going muon (upmu) events at
Super-Kamiokande. Datasets from SKI-SKIII (3109.6 days) were used for the
analysis. We looked for an excess of neutrino signal from the Sun as compared
with the expected atmospheric neutrino background in three upmu categories:
stopping, non-showering, and showering. No significant excess was observed. The
90% C.L. upper limits of upward-going muon flux induced by WIMPs of 100
GeV/c$^2$ were 6.4$\times10^{-15}$ cm$^{-2}$ sec$^{-1}$ and 4.0$\times10^{-15}$
cm$^{-2}$ sec$^{-1}$ for the soft and hard annihilation channels, respectively.
These limits correspond to upper limits of 4.5$\times10^{-39}$ cm$^{-2}$ and
2.7$\times10^{-40}$ cm$^{-2}$ for spin-dependent WIMP-nucleon scattering cross
sections in the soft and hard annihilation channels, respectively.
08/2011;
-
K Abe,
N Abgrall,
Y Ajima,
H Aihara,
J B Albert,
C Andreopoulos,
B Andrieu,
S Aoki,
O Araoka,
J Argyriades, [......],
N Yershov,
M Yokoyama,
A Zalewska,
J Zalipska,
L Zambelli,
K Zaremba,
M Ziembicki,
E D Zimmerman,
M Zito,
J Żmuda
[show abstract]
[hide abstract]
ABSTRACT: The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.
Physical Review Letters 07/2011; 107(4):041801. · 7.37 Impact Factor
-
Collaboration,
N. Abgrall,
H. Aihara,
Y. Ajima,
J. B. Albert,
D. Allan,
P. -A. Amaudruz,
C. Andreopoulos,
B. Andrieu,
M. D. Anerella, [......],
S. Yen,
N. Yershov,
M. Yokoyama,
A. Zalewska,
J. Zalipska,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: The T2K experiment is a long-baseline neutrino oscillation experiment. Its
main goal is to measure the last unknown lepton sector mixing angle
{\theta}_{13} by observing {\nu}_e appearance in a {\nu}_{\mu} beam. It also
aims to make a precision measurement of the known oscillation parameters,
{\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via {\nu}_{\mu} disappearance
studies. Other goals of the experiment include various neutrino cross section
measurements and sterile neutrino searches. The experiment uses an intense
proton beam generated by the J-PARC accelerator in Tokai, Japan, and is
composed of a neutrino beamline, a near detector complex (ND280), and a far
detector (Super-Kamiokande) located 295 km away from J-PARC. This paper
provides a comprehensive review of the instrumentation aspect of the T2K
experiment and a summary of the vital information for each subsystem.
06/2011;
-
K. Abe,
Y. Hayato,
T. Iida,
M. Ikeda,
C. Ishihara,
K. Iyogi,
J. Kameda,
K. Kobayashi,
Y. Koshio,
Y. Kozuma, [......],
S. Chen,
Y. Heng,
Z. Yang,
H. Zhang,
D. Kielczewska,
P. Mijakowski,
K. Connolly,
M. Dziomba,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: The results of the third phase of the Super-Kamiokande solar neutrino
measurement are presented and compared to the first and second phase results.
With improved detector calibrations, a full detector simulation, and improved
analysis methods, the systematic uncertainty on the total neutrino flux is
estimated to be ?2.1%, which is about two thirds of the systematic uncertainty
for the first phase of Super-Kamiokande. The observed 8B solar flux in the 5.0
to 20 MeV total electron energy region is 2.32+/-0.04 (stat.)+/-0.05 (sys.)
*10^6 cm^-2sec^-1, in agreement with previous measurements. A combined
oscillation analysis is carried out using SK-I, II, and III data, and the
results are also combined with the results of other solar neutrino experiments.
The best-fit oscillation parameters are obtained to be sin^2 {\theta}12 =
0.30+0.02-0.01(tan^2 {\theta}12 = 0.42+0.04 -0.02) and {\Delta}m2_21 =
6.2+1.1-1.9 *10^-5eV^2. Combined with KamLAND results, the best-fit oscillation
parameters are found to be sin^2 {\theta}12 = 0.31+/-0.01(tan^2 {\theta}12 =
0.44+/-0.03) and {\Delta}m2_21 = 7.6?0.2*10^-5eV^2 . The 8B neutrino flux
obtained from global solar neutrino experiments is
5.3+/-0.2(stat.+sys.)*10^6cm^-2s^-1, while the 8B flux becomes
5.1+/-0.1(stat.+sys.)*10^6cm^-2s^-1 by adding KamLAND result. In a three-flavor
analysis combining all solar neutrino experiments, the upper limit of sin^2
{\theta}13 is 0.060 at 95% C.L.. After combination with KamLAND results, the
upper limit of sin^2 {\theta}13 is found to be 0.059 at 95% C.L..
10/2010;
-
R. Wendell,
C. Ishihara,
K. Abe,
Y. Hayato,
T. Iida,
M. Ikeda,
K. Iyogi,
J. Kameda,
K. Kobayashi,
Y. Koshio, [......],
S. Chen,
Y. Heng,
Z. Yang,
H. Zhang,
D. Kielczewska,
P. Mijakowski,
K. Connolly,
M. Dziomba,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: We present a search for nonzero θ13 and deviations of sin2θ23 from 0.5 in the oscillations of atmospheric neutrino data from Super-Kamiokande I, II, and III. No distortions of the neutrino flux consistent with nonzero θ13 are found and both neutrino mass hierarchy hypotheses are in agreement with the data. The data are best fit at Δm2=2.1×10-3 eV2, sin2θ13=0.0, and sin2θ23=0.5. In the normal (inverted) hierarchy θ13 and Δm2 are constrained at the one-dimensional 90% C.L. to sin2θ13<0.04(0.09) and 1.9(1.7)×10-3<Δm2<2.6(2.7)×10-3 eV2. The atmospheric mixing angle is within 0.407≤sin2θ23≤0.583 at 90% C.L.
Phys. Rev. D. 05/2010; 81(9).
-
Super-Kamiokande Collaboration: R. Wendell,
C Ishihara,
K Abe,
Y. Hayato,
T Iida,
M Ikeda,
K. Iyogi,
J. Kameda,
K Kobayashi,
Y. Koshio, [......],
S Chen,
Y. Heng,
Z Yang,
H Zhang,
D. Kielczewska,
P. Mijakowski,
K Connolly,
M. Dziomba,
E. Thrane,
R. J. Wilkes
[show abstract]
[hide abstract]
ABSTRACT: We present a search for non-zero theta_{13} and deviations of sin^2
theta_{23} from 0.5 in the oscillations of atmospheric neutrino data from
Super-Kamiokande -I, -II, and -III. No distortions of the neutrino flux
consistent with non-zero theta_{13} are found and both neutrino mass hierarchy
hypotheses are in agreement with the data. The data are best fit at Delta m^2 =
2.1 x 10^-3 eV^2, sin^2 theta_{13} = 0.0, and sin^2 theta_{23} =0.5. In the
normal (inverted) hierarchy theta_{13} and Delta m^2 are constrained at the
one-dimensional 90% C.L. to sin^2 theta_{13} < 0.04 (0.09) and 1.9 (1.7) x
10^-3 < Delta m^2 < 2.6 (2.7) x 10^-3 eV^2. The atmospheric mixing angle is
within 0.407 <= sin^2 theta_{23} <= 0.583 at 90% C.L.
02/2010;
