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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
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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;
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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).
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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).
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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
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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
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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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P Adamson,
C Andreopoulos,
K E Arms,
R Armstrong,
D J Auty,
D S Ayres,
B Baller,
P D Barnes,
G Barr, W L Barrett, [......],
R C Webb,
A Wehmann,
N West,
C White,
S G Wojcicki,
D M Wright,
T Yang,
M Zois,
K Zhang,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Deltam2| = (2.43+/-0.13) x 10(-3) eV2 (68% C.L.) and mixing angle sin2(2theta) > 0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively.
Physical Review Letters 09/2008; 101(13):131802. · 7.37 Impact Factor
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P. Adamson,
C. Andreopoulos,
K. E. Arms,
R. Armstrong,
D. J. Auty,
S. Avvakumov,
D. S. Ayres,
B. Baller,
B. Barish,
Jr. P. D. Barnes, [......],
R. C. Webb,
A. Wehmann,
N. West,
C. White,
S. G. Wojcicki,
D. M. Wright,
T. Yang,
H. Zheng,
M. Zois,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We report the results of a search for νμ disappearance by the Main Injector Neutrino Oscillation Search [ D. G. Michael et al. Phys. Rev. Lett. 97 191801 (2006)]. The experiment uses two detectors separated by 734 km to observe a beam of neutrinos created by the Neutrinos at the Main Injector facility at Fermi National Accelerator Laboratory. The data were collected in the first 282 days of beam operations and correspond to an exposure of 1.27×1020 protons on target. Based on measurements in the Near Detector, in the absence of neutrino oscillations we expected 336±14 νμ charged-current interactions at the Far Detector but observed 215. This deficit of events corresponds to a significance of 5.2 standard deviations. The deficit is energy dependent and is consistent with two-flavor neutrino oscillations according to |Δm2|=2.74-0.26+0.44×10-3 eV2/c4 and sin22θ>0.87 at 68% confidence level.
Phys. Rev. D. 04/2008; 77(7).
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P. Adamson,
C. Andreopoulos,
K. E. Arms,
R. Armstrong,
D. J. Auty,
S. Avvakumov,
D. S. Ayres,
B. Baller,
B. Barish,
Jr. P. D. Barnes, [......],
N. West,
C. White,
S. G. Wojcicki,
D. M. Wright,
Q. K. Wu,
T. Yang,
F. X. Yumiceva,
H. Zheng,
M. Zois,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: The velocity of a ∼3 GeV neutrino beam is measured by comparing detection times at the near and far detectors of the MINOS experiment, separated by 734 km. A total of 473 far detector neutrino events was used to measure (v-c)/c=5.1±2.9×10-5 (at 68% C.L.). By correlating the measured energies of 258 charged-current neutrino events to their arrival times at the far detector, a limit is imposed on the neutrino mass of mν<50 MeV/c2 (99% C.L.).
Phys. Rev. D. 10/2007; 76(7).
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P. Adamson,
C. Andreopoulos,
K. E. Arms,
R. Armstrong,
D. J. Auty,
S. Avvakumov,
D. S. Ayres,
B. Baller,
B. Barish,
Jr. P. D. Barnes, [......],
N. West,
C. White,
S. G. Wojcicki,
D. M. Wright,
Q. K. Wu,
T. Yang,
F. X. Yumiceva,
H. Zheng,
M. Zois,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 m.w.e. in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be Nμ+/Nμ-=1.374±0.004(stat)-0.010+0.012(sys). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1–7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the 2 standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3–1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.
Phys. Rev. D. 09/2007; 76(5).
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P. Adamson,
C. Andreopoulos,
K. E. Arms,
R. Armstrong,
D. J. Auty,
S. Avvakumov,
D. S. Ayres,
B. Baller,
B. Barish,
Jr. P. D. Barnes, [......],
N. West,
C. White,
S. G. Wojcicki,
D. M. Wright,
Q. K. Wu,
T. Yang,
F. X. Yumiceva,
H. Zheng,
M. Zois,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: We found 140 neutrino-induced muons in 854.24 live days in the MINOS far detector, which has an acceptance for neutrino-induced muons of 6.91×106 cm2 sr. We looked for evidence of neutrino disappearance in this data set by computing the ratio of the number of low momentum muons to the sum of the number of high momentum and unknown momentum muons for both data and Monte Carlo expectation in the absence of neutrino oscillations. The ratio of data and Monte Carlo ratios, R, is R=0.65-0.12+0.15(stat)±0.09(syst), a result that is consistent with an oscillation signal. A fit to the data for the oscillation parameters sin22θ23 and Δm232 excludes the null oscillation hypothesis at the 94% confidence level. We separated the muons into μ- and μ+ in both the data and Monte Carlo events and found the ratio of the total number of μ- to μ+ in both samples. The ratio of those ratios, R̂CPT, is a test of CPT conservation. The result R̂CPT=0.72-0.18+0.24(stat)-0.04+0.08(syst) is consistent with CPT conservation.
Phys. Rev. D. 05/2007; 75(9).
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D G Michael,
P Adamson,
T Alexopoulos,
W W M Allison,
G J Alner,
K Anderson,
C Andreopoulos,
M Andrews,
R Andrews,
K E Arms, [......],
S G Wojcicki,
D M Wright,
Q K Wu,
W G Yan,
T Yang,
F X Yumiceva,
J C Yun,
H Zheng,
M Zois,
R Zwaska
[show abstract]
[hide abstract]
ABSTRACT: This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).
Physical Review Letters 11/2006; 97(19):191801. · 7.37 Impact Factor
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P. Adamson,
T. Alexopoulos,
W. W. M. Allison,
G. J. Alner,
K. Anderson,
C. Andreopoulos,
M. Andrews,
R. Andrews,
C. Arroyo,
S. Avvakumov, [......],
S. G. Wojcicki,
D. M. Wright,
Q. K. Wu,
W. G. Yan,
T. Yang,
F. X. Yumiceva,
J. C. Yun,
H. Zheng,
M. Zois,
R. Zwaska
[show abstract]
[hide abstract]
ABSTRACT: The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of νμ and ν̅ μ charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field νμ and ν̅ μ interactions are separated. The ratio of ν̅ μ to νμ events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving Rν̅ μ/νμdata/Rν̅ μ/νμMC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for νμ and ν̅ μ.
Phys. Rev. D. 04/2006; 73(7).
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M. Sanchez,
W. W. M. Allison,
G. J. Alner,
D. S. Ayres, W. L. Barrett,
P. M. Border,
J. H. Cobb,
D. J. A. Cockerill,
H. Courant,
D. M. Demuth, [......],
W. P. Oliver,
G. F. Pearce,
E. A. Peterson,
D. A. Petyt,
K. Ruddick,
J. Schneps,
A. Sousa,
B. Speakman,
J. L. Thron,
N. West
[show abstract]
[hide abstract]
ABSTRACT: A deficit of atmospheric νμ events, consistent with the hypothesis of neutrino oscillations, is observed in the 5.90 kiloton-year fiducial exposure of the Soudan 2 detector. An unbinned maximum likelihood analysis of the neutrino L/E distribution has been carried out using the Feldman-Cousins prescription. The probability of the no oscillation hypothesis is 5.8×10-4. The 90% confidence allowed region in the sin22θ,Δm2 plane is presented. The region includes the 90% confidence allowed region of the Super-K experiment.
Phys. Rev. D. 12/2003; 68(11).
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P. Adamson,
K. Alexandrov,
G Alexeev,
T. Alexopoulos,
W W M Allison,
G J Alner,
B Anderson,
D. F. Anderson,
K Anderson,
C. Andreopoulos, [......],
V Semenov,
I Shein,
B.W. Sheng,
A Sisakian,
W. Smart,
V. Smirnitsky,
C Smith,
P. N. Smith,
V. Smotriaev,
A Soldatov
IEEE Transactions on Nuclear Science 07/2002; 49(3):861- 863. · 1.45 Impact Factor
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D. Wall,
W. W. M. Allison,
G. J. Alner,
D. S. Ayres, W. L. Barrett,
C. Bode,
P. M. Border,
J. H. Cobb,
R. Cotton,
H. Courant, [......],
E. A. Peterson,
D. A. Petyt,
L. E. Price,
K. Ruddick,
M. Sanchez,
J. Schneps,
A. Stassinakis,
J. L. Thron,
S. P. Wakely,
N. West
[show abstract]
[hide abstract]
ABSTRACT: We have searched for nucleon decay into five two-body final states using a 4.4 kiloton-year fiducial exposure of the Soudan 2 iron tracking calorimeter. For proton decay into the fully visible final states μ+η0 and e+η0, we observe zero and one event, respectively, that satisfy our search criteria for nucleon decay. The lifetime lower limits (τ/B) thus implied are 89×1030years and 81×1030years at 90% confidence level. For neutron decay into ν̅ η0, we obtain the lifetime lower limit 71×1030years. Limits are also reported for neutron decay into ν̅ π0, and for proton decay into ν̅ π+.
Phys. Rev. D. 10/2000; 62(9).
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W W M Allison,
G J Alner,
C. B. Brooks,
J Byrne,
J H Cobb,
S Cooper,
R. J. Cotton,
P. G. Dawber,
K Green,
P. G. Harris, [......],
D H Perkins,
D. A. Petyt,
P D Shield,
J Thomas,
R L Wastie,
E. Ables,
D. S. Ayres,
B. Barish, W. L. Barrett,
R. H. Bernstein
[show abstract]
[hide abstract]
ABSTRACT: J. Guarino 1 , J. Hanson 3 , R. Heinz 7 , K. Heller 11 , N. Hill 1 , Y. Ho 4 , G. Irwin 15 , U. Jagadish 12 , D. Johnson 5 , T. Kafka 18 , G. Koizumi 5 , E. P. Kuznetsov 9 , A. Lan 6 , K. Lau 6 , W. Lee 4 , M. Libkind 10 , J.Liu 6 , N. P. Longley 3 , W. A. Mann 18 , M. L. Marshak 11 , D. Maxam 11 , E. N. May 1 , B. Mayes 6 , D. G. Michael 3 , R. H. Milburn 18 , L. Miller 7 , W. H. Miller 11 , G. Mitselmakher 5 , G. Mo 6 , J. Morfin 5 , S. Mrenna 3 , S. Mufson<F5.1
12/1999;
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[show abstract]
[hide abstract]
ABSTRACT: Introduction In the summer of 1996, Louis Barrett noticed that there had been a sharp rise in the trigger rate but he was unable to find a source of the rise. In the summer of 1997, he and Bill Miller again noticed a sharp rise and postulated that the rise was a seasonal one. The effect became known as the "Bill-Louis" effect. Further investigation showed that the reconstructed muon rate showed the same effect but the rise was smaller. In the mine, the temperature is quite constant year round, so the cause of this seasonal effects were not immediately clear. 1 The 5% rise in the muon rate has also been seen in other experiments, and is understood as an effect due to seasonal changes in temperature in the upper atmosphere. The average temperature change between summer and winter is 30 o K. At a point of fixed pressure in the atmosphere (i.e. fixed overburden), this Sigma5% change in the temperature results in a<F
12/1999;
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G J Alner,
D. S. Ayres,
B. C. Barish, W. L. Barrett,
R. E. Blair,
C Bode,
C Bower,
J Cobb,
D J A Cockerill,
R Cotton, [......],
B Ewen,
T. H. Fields,
W. Gajewski,
H Gallagher,
C. Giller,
M Goodman,
Y. Ho,
J. Hong,
T Kafka,
E. Katsavounidis
[show abstract]
[hide abstract]
ABSTRACT: A very large (nominally 17 KT) fine-grained, magnetic sampling calorimeter is discussed for use in studying events induced by accelerator or atmospheric neutrinos for the purpose of searching for neutrino oscillations. This detector allows a number of possible signatures for neutrino oscillations based on disappearance of muon neutrinos, ratio of neutral current to charged current events and appearance of tau or electron neutrinos by additional electromagnetic showers or apparent `neutral current' events giving hadronic showers in the detector. Most importantly, the detector can provide an unambiguous signature of tau appearance using the muon decay channel of the tau, particularly if a narrow-band beam is employed. The proposed detector will also represent a major stand-alone underground detector facility for non-accelerator physics. Atmospheric neutrinos can be collected during the same period as beam measurements are made and allow an extension of sensitivity to smaller Deltam 2 ...
12/1999;
