-
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;
-
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;
-
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;
-
J. L. Hewett,
H. Weerts,
R. Brock,
J. N. Butler,
B. C. K. Casey,
J. Collar,
A. de Gouvea,
R. Essig,
Y. Grossman,
W. Haxton, [......],
J. Yeck,
M. Yeh,
M. Yokoyama,
J. Yoo,
A. Young,
E. Zimmerman,
K. Zioutas,
M. Zisman,
J. Zupan,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: The Proceedings of the 2011 workshop on Fundamental Physics at the Intensity
Frontier. Science opportunities at the intensity frontier are identified and
described in the areas of heavy quarks, charged leptons, neutrinos, proton
decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms.
05/2012;
-
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;
-
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;
-
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
-
P Adamson,
D J Auty,
D S Ayres,
C Backhouse,
G Barr,
M Bishai,
A Blake,
G J Bock,
D J Boehnlein,
D Bogert, [......],
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: Results are reported from a search for active to sterile neutrino oscillations in the MINOS long-baseline experiment, based on the observation of neutral-current neutrino interactions, from an exposure to the NuMI neutrino beam of 7.07×10(20) protons on target. A total of 802 neutral-current event candidates is observed in the Far Detector, compared to an expected number of 754 ± 28(stat) ± 37(syst) for oscillations among three active flavors. The fraction f(s) of disappearing ν(μ) that may transition to ν(s) is found to be less than 22% at the 90% C.L.
Physical Review Letters 07/2011; 107(1):011802. · 7.37 Impact Factor
-
P Adamson,
C Andreopoulos,
R Armstrong,
D J Auty,
D S Ayres,
C Backhouse,
G Barr,
M Bishai,
A Blake,
G J Bock, [......],
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: Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of 7.25×10(20) protons on target. A fit to neutrino oscillations yields values of |Δm(2)|=(2.32(-0.08)(+0.12))×10(-3) eV(2) for the atmospheric mass splitting and sin(2)(2θ)>0.90 (90% C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively.
Physical Review Letters 05/2011; 106(18):181801. · 7.37 Impact Factor
-
P Adamson,
D J Auty,
D S Ayres,
C Backhouse,
G Barr,
W L Barrett,
M Bishai,
A Blake,
G J Bock,
D J Boehnlein, [......],
B Viren,
A Weber,
R C Webb,
C White,
L Whitehead,
S G Wojcicki,
D M Wright,
T Yang,
M Zois,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be a consequence of Lorentz and CPT violation as described by the standard-model extension framework. It also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We found no evidence for this sidereal signature, and the upper limits placed on the magnitudes of the Lorentz and CPT violating coefficients describing the theory are an improvement by factors of 20-510 over the current best limits found by using the MINOS near detector.
Physical Review Letters 10/2010; 105(15):151601. · 7.37 Impact Factor
-
P Adamson,
C Andreopoulos,
D S Ayres,
C Backhouse,
G Barr,
W L Barrett,
M Bishai,
A Blake,
B Bock,
G J Bock, [......],
R Toner,
G Tzanakos,
J Urheim,
P Vahle,
P B Viren,
A Weber,
R C Webb,
C White,
L Whitehead,
S G Wojcicki
09/2010;
-
P. Adamson,
C. Andreopoulos,
K. E. Arms,
R. Armstrong,
D. J. Auty,
D. S. Ayres,
C. Backhouse,
Jr. P. D. Barnes,
G. Barr,
W. L. Barrett, [......],
R. C. Webb,
N. West,
C. White,
L. Whitehead,
S. G. Wojcicki,
D. M. Wright,
T. Yang,
M. Zois,
K. Zhang,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: The energy dependence of the neutrino-iron and antineutrino-iron inclusive charged-current cross sections and their ratio have been measured using a high-statistics sample with the MINOS near detector exposed to the NuMI beam from the main injector at Fermilab. Neutrino and antineutrino fluxes were determined using a low hadronic energy subsample of charged-current events. We report measurements of ν-Fe (ν̅ -Fe) cross section in the energy range 3–50 GeV (5–50 GeV) with precision of 2%–8% (3%–9%) and their ratio which is measured with precision 2%–8%. The data set spans the region from low energy, where accurate measurements are sparse, up to the high-energy scaling region where the cross section is well understood.
Phys. Rev. D. 04/2010; 81(7).
-
P. Adamson,
C. Andreopoulos,
D. J. Auty,
D. S. Ayres,
C. Backhouse,
Jr. P. D. Barnes,
G. Barr,
W. L. Barrett,
M. Bishai,
A. Blake, [......],
A. Weber,
R. C. Webb,
N. West,
C. White,
L. Whitehead,
S. G. Wojcicki,
D. M. Wright,
T. Yang,
K. Zhang,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: A search for depletion of the combined flux of active neutrino species over a 735 km baseline is reported using neutral-current interaction data recorded by the MINOS detectors in the NuMI neutrino beam. Such a depletion is not expected according to conventional interpretations of neutrino oscillation data involving the three known neutrino flavors. A depletion would be a signature of oscillations or decay to postulated noninteracting sterile neutrinos, scenarios not ruled out by existing data. From an exposure of 3.18×1020 protons on target in which neutrinos of energies between ∼500 MeV and 120 GeV are produced predominantly as νμ, the visible energy spectrum of candidate neutral-current reactions in the MINOS far detector is reconstructed. Comparison of this spectrum to that inferred from a similarly selected near-detector sample shows that of the portion of the νμ flux observed to disappear in charged-current interaction data, the fraction that could be converting to a sterile state is less than 52% at 90% confidence level (C.L.). The hypothesis that active neutrinos mix with a single sterile neutrino via oscillations is tested by fitting the data to various models. In the particular four-neutrino models considered, the mixing angles θ24 and θ34 are constrained to be less than 11° and 56° at 90% C.L., respectively. The possibility that active neutrinos may decay to sterile neutrinos is also investigated. Pure neutrino decay without oscillations is ruled out at 5.4 standard deviations. For the scenario in which active neutrinos decay into sterile states concurrently with neutrino oscillations, a lower limit is established for the neutrino decay lifetime τ3/m3>2.1×10-12 s/eV at 90% C.L.
Phys. Rev. D. 03/2010; 81(5).
-
P Adamson,
C Andreopoulos,
K E Arms,
R Armstrong,
D J Auty,
D S Ayres,
C Backhouse,
P D Barnes,
G Barr,
W L Barrett, [......],
N West,
C White,
L Whitehead,
S G Wojcicki,
D M Wright,
T Yang,
K Zhang,
H Zheng,
M Zois,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 and sin2(2theta(23))=1.0 are assumed.
Physical Review Letters 12/2009; 103(26):261802. · 7.37 Impact Factor
-
P Adamson,
C Andreopoulos,
K E Arms,
R Armstrong,
D J Auty,
D S Ayres,
C Backhouse,
B Baller,
G Barr,
W L Barrett, [......],
A Weber,
R C Webb,
A Wehmann,
N West,
C White,
S G Wojcicki,
D M Wright,
T Yang,
K Zhang,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.
Physical Review Letters 12/2008; 101(22):221804. · 7.37 Impact Factor
-
P Adamson,
C Andreopoulos,
K E Arms,
R Armstrong,
D J Auty,
D S Ayres,
B Baller,
G Barr,
W L Barrett,
B R Becker, [......],
A Weber,
R C Webb,
A Wehmann,
N West,
C White,
S G Wojcicki,
T Yang,
M Zois,
K Zhang,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: A search for a sidereal modulation in the MINOS near detector neutrino data was performed. If present, this signature could be a consequence of Lorentz and CPT violation as predicted by the effective field theory called the standard-model extension. No evidence for a sidereal signal in the data set was found, implying that there is no significant change in neutrino propagation that depends on the direction of the neutrino beam in a sun-centered inertial frame. Upper limits on the magnitudes of the Lorentz and CPT violating terms in the standard-model extension lie between 10(-4) and 10(-2) of the maximum expected, assuming a suppression of these signatures by a factor of 10(-17).
Physical Review Letters 11/2008; 101(15):151601. · 7.37 Impact Factor
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K. Kodama,
N. Ushida,
C. Andreopoulos,
N. Saoulidou,
G. Tzanakos,
P. Yager,
B. Baller,
D. Boehnlein,
W. Freeman,
B. Lundberg, [......],
B. D. Park,
O. Sato,
S. Takahashi,
V. Paolone,
C. Rosenfeld,
A. Kulik,
T. Kafka,
W. Oliver,
T. Patzak, J. Schneps
[show abstract]
[hide abstract]
ABSTRACT: The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed ντ charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on 3.6×1017 protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed ντ CC events is 9 with an estimated background of 1.5 events, from a total of 578 observed neutrino interactions. We calculate the ντ CC cross section as a function of one parameter. Assuming Ds mesons are the sole source for ντ, the energy-independent part of the total CC cross section can be parametrized as σconst(ντ)=2.51n1.52×10-40 cm2 GeV-1 for n≥4, where n is the parameter controlling the longitudinal part of the Ds differential cross section of the form dσ/dxF∝(1-|xF|)n. The analysis could not distinguish between ντ and ν̅ τ. The value of n obtained from Pythia simulations, n=6.1, gives an estimated value of σconst(ντ)=(0.39±0.13±0.13)×10-38 cm2 GeV-1.
Phys. Rev. D. 09/2008; 78(5).
