-
D. Adey,
S. K. Agarwalla,
C. M. Ankenbrandt,
R. Asfandiyarov,
J. J. Back,
G. Barker,
E. Baussan,
R. Bayes,
S. Bhadra,
V. Blackmore, [......],
C. Touramanis,
C. D. Tunnel,
Y. Uchida,
N. Vassilopoulos,
M. O. Wascko, A. Weber,
E. Wildner,
M. J. Wilking,
W. Winter,
U. K. Yang
[show abstract]
[hide abstract]
ABSTRACT: The nuSTORM facility has been designed to deliver beams of electron and muon
neutrinos from the decay of a stored muon beam with a central momentum of 3.8
GeV/c and a momentum spread of 10%. The facility is unique in that it will:
serve the future long- and short-baseline neutrino-oscillation programmes by
providing definitive measurements of electron-neutrino- and
muon-neutrino-nucleus cross sections with percent-level precision; allow
searches for sterile neutrinos of exquisite sensitivity to be carried out; and
constitute the essential first step in the incremental development of muon
accelerators as a powerful new technique for particle physics.
Of the world's proton-accelerator laboratories, only CERN and FNAL have the
infrastructure required to mount nuSTORM. Since no siting decision has yet been
taken, the purpose of this Expression of Interest (EoI) is to request the
resources required to: investigate in detail how nuSTORM could be implemented
at CERN; and develop options for decisive European contributions to the nuSTORM
facility and experimental programme wherever the facility is sited.
The EoI defines a two-year programme culminating in the delivery of a
Technical Design Report.
05/2013;
-
MINOS Collaboration,
P. Adamson,
I. Anghel,
C. Backhouse,
G. Barr,
M. Bishai,
A. Blake,
G. J. Bock,
D. Bogert,
S. V. Cao, [......],
J. Urheim,
P. Vahle,
B. Viren, A. Weber,
R. C. Webb,
C. White,
L. Whitehead,
L. H. Whitehead,
S. G. Wojcicki,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report measurements of oscillation parameters from $\nu_{mu}$ and
$\bar{\nu}_{\mu}$ disappearance using beam and atmospheric data from MINOS. The
data comprise exposures of \unit[$10.71 \times 10^{20}$]{protons on target
(POT)} in the $\nu_{\mu}$-dominated beam, $\unit[3.36\times10^{20}]{POT}}$ in
the $\bar{\nu}_{\mu}$-enhanced beam, and 37.88 kton-years of atmospheric
neutrinos. Assuming identical $\nu$ and $\bar{\nu}$ oscillation parameters, we
measure \mbox{$|\Delta m^2}| = \unit[2.41^{+0.09}_{-0.10}) \times
10^{-3}]{eV^{2}}$} and $\sin^{2}/!/left(2\theta \right) =
0.950^{+0.035}_{-0.036}$. Allowing independent $\nu$ and $\bar{\nu}$
oscillations, we measure antineutrino parameters of $|\Delta \bar{m}^2| =
\unit[(2.50 ^{+0.23}_{-0.25}) \times 10^{-3}]{eV^{2}}$ and
$\sin^{2}/!/left(2\bar{\theta} \right) = 0.97^{+0.03}_{-0.08}$, with minimal
change to the neutrino parameters.
04/2013;
-
K. Abe,
N. Abgrall,
H. Aihara,
T. Akiri,
J. B. Albert,
C. Andreopoulos,
S. Aoki,
A. Ariga,
T. Ariga,
S. Assylbekov, [......],
N. Yershov,
M. Yokoyama,
Ì T. Yuan,
A. Zalewska,
L. Zambelli,
K. Zaremba,
M. Ziembicki,
E. D. Zimmerman,
M. Zito,
and J. Zmuda
[show abstract]
[hide abstract]
ABSTRACT: T2K has performed the first measurement of \nu{\mu} inclusive charged current
interactions on carbon at neutrino energies of ~1 GeV where the measurement is
reported as a flux-averaged double differential cross section in muon momentum
and angle. The flux is predicted by the beam Monte Carlo and external data,
including the results from the NA61/SHINE experiment. The data used for this
measurement were taken in 2010 and 2011, with a total of 10.8 x 10^{19}
protons-on-target. The analysis is performed on 4485 inclusive charged current
interaction candidates selected in the most upstream fine-grained scintillator
detector of the near detector.
The flux-averaged total cross section is <\sigma_CC>_\phi =(6.91 +/- 0.13
(stat) +/- 0.84 (syst)) x10^{-39} cm^2/nucleon for a mean neutrino energy of
0.85 GeV.
02/2013;
-
P. Adamson,
I. Anghel,
C. Backhouse,
G. Barr,
M. Bishai,
A. Blake,
G. J. Bock,
D. Bogert,
S. V. Cao,
D. Cherdack, [......],
J. Urheim,
P. Vahle,
B. Viren, A. Weber,
R. C. Webb,
C. White,
L. Whitehead,
S. G. Wojcicki,
T. Yang,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report on $\nu_e$ and $\bar{\nu}_e$ appearance in $\nu_\mu$ and
$\bar{\nu}_\mu$ beams using the full MINOS data sample. The comparison of these
$\nu_e$ and $\bar{\nu}_e$ appearance data at a 735 km baseline with
$\theta_{13}$ measurements by reactor experiments probes $\delta$, the
$\theta_{23}$ octant degeneracy, and the mass hierarchy. This analysis is the
first use of this technique and includes the first accelerator long-baseline
search for $\bar{\nu}_\mu\rightarrow\bar{\nu}_e$. Our data disfavor 31% (5%) of
the three-parameter space defined by $\delta$, the octant of the $\theta_{23}$,
and the mass hierarchy at the 68% (90%) C.L. We measure a value of
2sin$^2(2\theta_{13})$sin$^2(\theta_{23})$ that is consistent with reactor
experiments.
01/2013;
-
S. Aoki,
G. Barr,
M. Batkiewicz,
J. Błocki,
J. D. Brinson,
W. Coleman,
A. Daιbrowska,
I. Danko,
M. Dziewiecki,
B. Ellison, [......],
M. Szeptycka,
M. Thorpe,
T. Waιchała,
D. Warner, A. Weber,
T. Yano,
N. Yershov,
A. Zalewska,
K. Zaremba,
M. Ziembicki
[show abstract]
[hide abstract]
ABSTRACT: The T2K experiment is a long baseline neutrino oscillation experiment aiming
to observe the appearance of {\nu} e in a {\nu}{\mu} beam. The {\nu}{\mu} beam
is produced at the Japan Proton Accelerator Research Complex (J-PARC), observed
with the 295 km distant Super- Kamiokande Detector and monitored by a suite of
near detectors at 280m from the proton target. The near detectors include a
magnetized off-axis detector (ND280) which measures the un-oscillated neutrino
flux and neutrino cross sections. The present paper describes the outermost
component of ND280 which is a side muon range detector (SMRD) composed of
scintillation counters with embedded wavelength shifting fibers and Multi-Pixel
Photon Counter read-out. The components, performance and response of the SMRD
are presented.
Nuclear Inst. and Methods in Physics Research, A. 01/2013; 698:135-146.
-
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;
-
MINOS Collaboration,
P. Adamson,
C. Backhouse,
G. Barr,
M. Bishai,
A. S. T. Blake,
G. J. Bock,
D. J. Boehnlein,
D. Bogert,
S. V. Cao, [......],
P. Vahle,
B. Viren,
J. J. Walding, A. Weber,
R. C. Webb,
C. White,
L. Whitehead,
S. G. Wojcicki,
K. Zhang,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: This paper reports measurements of atmospheric neutrino and antineutrino
interactions in the MINOS Far Detector, based on 2553 live-days (37.9
kton-years) of data. A total of 2072 candidate events are observed. These are
separated into 905 contained-vertex muons and 466 neutrino-induced rock-muons,
both produced by charged-current $\nu_{\mu}$ and $\bar{\nu}_{\mu}$
interactions, and 701 contained-vertex showers, composed mainly of
charged-current $\nu_{e}$ and $\bar{\nu}_{e}$ interactions and neutral-current
interactions. The curvature of muon tracks in the magnetic field of the MINOS
Far Detector is used to select separate samples of $\nu_{\mu}$ and
$\bar{\nu}_{\mu}$ events. The observed ratio of $\bar{\nu}_{\mu}$ to
$\nu_{\mu}$ events is compared with the Monte Carlo simulation, giving a double
ratio of $R^{data}_{\bar{\nu}/\nu}/R^{MC}_{\bar{\nu}/\nu} = 1.03 \pm 0.08
(stat.) \pm 0.08 (syst.)$. The $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ data are
separated into bins of $L/E$ resolution, based on the reconstructed energy and
direction of each event, and a maximum likelihood fit to the observed $L/E$
distributions is used to determine the atmospheric neutrino oscillation
parameters. This fit returns 90% confidence limits of $|\Delta m^{2}| = (1.9
\pm 0.4) \times 10^{-3} eV^{2}$ and $sin^{2} 2\theta > 0.86$. The fit is
extended to incorporate separate $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ oscillation
parameters, returning 90% confidence limits of $|\Delta m^{2}|-|\Delta
\bar{m}^{2}| = 0.6^{+2.4}_{-0.8} \times 10^{-3} eV^{2}$ on the difference
between the squared-mass splittings for neutrinos and antineutrinos.
08/2012;
-
S Wolfart,
B Marré,
B Wöstmann,
M Kern,
T Mundt,
R G Luthardt,
J Huppertz,
W Hannak,
T Reiber,
N Passia,
G Heydecke,
W Reinhardt,
S Hartmann,
E Busche,
G Mitov,
H Stark,
P Pospiech, A Weber,
W Gernet,
M H Walter
[show abstract]
[hide abstract]
ABSTRACT: The scientific evidence concerning prosthodontic care for the shortened dental arch (SDA) is sparse. This randomized multicenter study aimed to compare two common treatment options: removable partial dental prostheses (RPDPs) for molar replacement vs. no replacement (SDA). One of the hypotheses was that the follow-up treatment differs between patients with RPDPs and patients with SDAs during the 5-year follow-up period. Two hundred and fifteen patients with complete molar loss in one jaw were included in the study. Molars were either replaced by RPDPs or not replaced according to the SDA concept. A mean number of 4.2 (RPDP) and 2.8 (SDA) treatments for biological or technical reasons occurred during the 5-year observation time per patient. Concerning the biological aspect, no significant differences between the groups could be shown, whereas treatment arising from technical reasons was significantly more frequent for the RPDP group. When the severity of treatment was analyzed, a change over time was evident. When, at baseline, only follow-up treatment with minimal effort is required, over time there is a continuous increase to moderate and extensive effort observed for both groups (Controlled-trials.com number ISRCTN97265367).
Journal of dental research 07/2012; 91(7 Suppl):65S-71S. · 3.46 Impact Factor
-
M H Walter,
W Hannak,
M Kern,
T Mundt,
W Gernet, A Weber,
B Wöstmann,
H Stark,
D Werner,
S Hartmann, [......],
F Jahn,
N Passia,
P Pospiech,
G Mitov,
J Brückner,
S Wolfart,
E Busche,
R G Luthardt,
G Heydecke,
B Marré
[show abstract]
[hide abstract]
ABSTRACT: OBJECTIVES: The study was designed to provide clinical outcome data for two treatments of the shortened dental arch (SDA). MATERIAL AND METHODS: In a multicenter randomized controlled clinical trial, patients with complete molar loss in one jaw were provided with either a partial removable dental prosthesis (PRDP) retained with precision attachments or treated according to the SDA concept preserving or restoring a premolar occlusion. No implants were placed. The primary outcome was tooth loss. RESULTS: Of 152 treated patients, 132 patients reached the 5-year examination. Over 5 years, 38 patients experienced tooth loss. For the primary outcome tooth loss, the Kaplan-Meier survival rates at 5 years were 0.74 (95 % CI 0.64, 0.84) in the PRDP group and 0.74 (95 % CI 0.63, 0.85) in the SDA group. For tooth loss in the study jaw, the survival rates at 5 years were 0.88 (95 % CI 0.80, 0.95) in the PRDP group and 0.84 (95 % CI 0.74, 0.93) in the SDA group. The differences were not significant. No Cox regression models of appropriate fit explaining tooth loss on the patient level could be found. CONCLUSIONS: The overall treatment goals of a sustainable oral rehabilitation and the avoidance of further tooth loss over longer periods were not reliably achievable. The influence of the type of prosthetic treatment on tooth loss might have been overestimated. CLINICAL RELEVANCE: Regarding our results, the patient's view will gain even more importance in the clinical decision between removable and fixed restorations in SDAs.
Clinical Oral Investigations 06/2012; · 2.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In this article we describe how two or more experimental results can be
combined within the procedure of Feldman and Cousins, to provide combined
confidence limits on the physical parameters of interest. We demonstrate the
technique by combining the recent electron neutrino appearance results from T2K
and MINOS. Our best fit point is sin^{2}2\theta_{13} = 0.08 (0.11) and \delta =
1.1 (2.0) \pi; in addition we exclude sin^{2}2\theta_{13}=0 at 2.7 \sigma (2.8
\sigma) for the normal (inverted) neutrino mass hierarchy.
04/2012;
-
P. Adamson,
D. S. Ayres,
C. Backhouse,
G. Barr,
M. Bishai,
A. Blake,
G. J. Bock,
D. J. Boehnlein,
D. Bogert,
S. V. Cao, [......],
J. Urheim,
P. Vahle,
B. Viren,
J. J. Walding, A. Weber,
R. C. Webb,
C. White,
L. Whitehead,
S. G. Wojcicki,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report an improved measurement of muon anti-neutrino disappearance over a
distance of 735km using the MINOS detectors and the Fermilab Main Injector
neutrino beam in a muon anti-neutrino enhanced configuration. From a total
exposure of 2.95e20 protons on target, of which 42% have not been previously
analyzed, we make the most precise measurement of the anti-neutrino
"atmospheric" delta-m squared = 2.62 +0.31/-0.28 (stat.) +/- 0.09 (syst.) and
constrain the anti-neutrino atmospheric mixing angle >0.75 (90%CL). These
values are in agreement with those measured for muon neutrinos, removing the
tension reported previously.
02/2012;
-
P. Adamson,
D. S. Ayres,
G. Barr,
M. Bishai,
A. Blake,
G. J. Bock,
D. J. Boehnlein,
D. Bogert,
S. V. Cao,
S. Cavanaugh, [......],
J. Urheim,
P. Vahle,
B. Viren,
J. J. Walding, A. Weber,
R. C. Webb,
C. White,
L. Whitehead,
S. G. Wojcicki,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We have searched for sidereal variations in the rate of antineutrino
interactions in the MINOS Near Detector. Using antineutrinos produced by the
NuMI beam, we find no statistically significant sidereal modulation in the
rate. When this result is placed in the context of the Standard Model Extension
theory we are able to place upper limits on the coefficients defining the
theory. These limits are used in combination with the results from an earlier
analysis of MINOS neutrino data to further constrain the coefficients.
01/2012;
-
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;
-
S. Assylbekov,
B. E. Berger,
H. Berns,
D. Beznosko,
A. Bodek,
R. Bradford,
N. Buchanan,
H. Budd,
Y. Caffari,
K. Connolly, [......],
A. S. Tadepalli,
I. J. Taylor,
W. Toki,
C. Vanek,
D. Warner, A. Weber,
R. J. Wilkes,
R. J. Wilson,
C. Yanagisawa,
T. Yuan
[show abstract]
[hide abstract]
ABSTRACT: The Pi-Zero detector (P{\O}D) is one of the subdetectors that makes up the
off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino
experiment. The primary goal for the P{\O}D is to measure the relevant cross
sections for neutrino interactions that generate pi-zero's, especially the
cross section for neutral current pi-zero interactions, which are one of the
dominant sources of background to the electron neutrino appearance signal in
T2K. The P{\O}D is composed of layers of plastic scintillator alternating with
water bags and brass sheets or lead sheets and is one of the first detectors to
use Multi-Pixel Photon Counters (MPPCs) on a large scale.
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;
-
P Adamson,
D J Auty,
D S Ayres,
C Backhouse,
G Barr,
M Betancourt,
M Bishai,
A Blake,
G J Bock,
D J Boehnlein, [......],
P Vahle,
B Viren,
J J Walding, A Weber,
R C Webb,
C White,
L Whitehead,
S G Wojcicki,
T Yang,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report the results of a search for ν(e) appearance in a ν(μ) beam in the MINOS long-baseline neutrino experiment. With an improved analysis and an increased exposure of 8.2 × 10(20) protons on the NuMI target at Fermilab, we find that 2 sin(2) (θ(23))sin(2)(2θ(13))<0.12(0.20) at 90% confidence level for δ = 0 and the normal (inverted) neutrino mass hierarchy, with a best-fit of 2sin(2) (θ(23))sin(2)(2θ(13)) = 0.041(-0.031)(+0.047) (0.079(-0.053) (+0.071)). The θ(13) = 0 hypothesis is disfavored by the MINOS data at the 89% confidence level.
Physical Review Letters 10/2011; 107(18):181802. · 7.37 Impact Factor
-
The LBNE Collaboration,
T. Akiri,
D. Allspach,
M. Andrews,
K Arisaka,
E. Arrieta-Diaz,
M. Artuso,
X Bai,
B. Balantekin,
B. Baller, [......],
W. Willis,
R J Wilson,
L. Winslow,
J Ye,
M Yeh,
B Yu,
G. Zeller,
C Zhang,
E Zimmerman,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: In early 2010, the Long-Baseline Neutrino Experiment (LBNE) science
collaboration initiated a study to investigate the physics potential of the
experiment with a broad set of different beam, near- and far-detector
configurations. Nine initial topics were identified as scientific areas that
motivate construction of a long-baseline neutrino experiment with a very large
far detector. We summarize the scientific justification for each topic and the
estimated performance for a set of far detector reference configurations. We
report also on a study of optimized beam parameters and the physics capability
of proposed Near Detector configurations. This document was presented to the
collaboration in fall 2010 and updated with minor modifications in early 2011.
10/2011;
-
MINOS Collaboration,
P. Adamson,
D. J. Auty,
D. S. Ayres,
C Backhouse,
G Barr,
M Bishai,
A Blake,
G J Bock,
D. J. Boehnlein, [......],
P. Vahle,
B. Viren,
J. J. Walding, A Weber,
R. C. Webb,
C White,
L. Whitehead,
S. G. Wojcicki,
T Yang,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report constraints on antineutrino oscillation parameters that were
obtained by using the two MINOS detectors to measure the 7% muon antineutrino
component of the NuMI neutrino beam. In the Far Detector, we select 130 events
in the charged-current muon antineutrino sample, compared to a prediction of
136.4 +/- 11.7(stat) ^{+10.2}_{-8.9}(syst) events under the assumption
|dm2bar|=2.32x10^-3 eV^2, snthetabar=1.0. Assuming no oscillations occur at the
Near Detector baseline, a fit to the two-flavor oscillation approximation
constrains |dm2bar|<3.37x10^-3 eV^2 at the 90% confidence level with
snthetabar=1.0.
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
-
P Adamson,
C Andreopoulos,
D J Auty,
D S Ayres,
C Backhouse,
G Barr,
M Bishai,
A Blake,
G J Bock,
D J Boehnlein, [......],
J Urheim,
P Vahle,
B Viren, A Weber,
R C Webb,
C White,
L Whitehead,
S G Wojcicki,
T Yang,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν(μ) production, accumulating an exposure of 1.71 × 10²⁰ protons on target. In the Far Detector, 97 charged current ν(μ) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm²| = [3.36(-0.40)(+0.46)(stat) ± 0.06(syst)] × 10⁻³ eV², sin²(2θ) = 0.86(-0.12)(+0.11)(stat) ± 0.01(syst). The MINOS ν(μ) and ν(μ) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.
Physical Review Letters 07/2011; 107(2):021801. · 7.37 Impact Factor
