The Main Injector Neutrino Oscillation Search (MINOS) experiment uses an acceleratorproduced neutrino beam to perform precision measurements of the neutrino oscillation parameters in the "atmospheric neutrino" sector associated with muon neutrino disappearance. This long-baseline experiment measures neutrino interactions in Fermilab's NuMI neutrino beam with a near detector at Fermilab and again 735 km downstream with a far detector in the Soudan Underground Laboratory in northern Minnesota. The two detectors are magnetized steel-scintillator tracking calorimeters. They are designed to be as similar as possible in order to ensure that differences in detector response have minimal impact on the comparisons of event rates, energy spectra and topologies that are essential to MINOS measurements of oscillation parameters. The design, construction, calibration and performance of the far and near detectors are described in this paper.

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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.

We report on νe andνe appearance in νµ andνµ beams using the full MINOS data sample. The comparison of these νe andνe appearance data at a 735 km baseline with θ13 measurements by reactor experiments probes δ, the θ23 octant degeneracy, and the mass hierarchy. This analysis is the first use of this technique and includes the first accelerator long-baseline search forνµ →νe. Our data disfavor 31% (5%) of the three-parameter space defined by δ, the octant of the θ23, and the mass hierarchy at the 68% (90%) C.L. We measure a value of 2sin 2 (2θ13)sin 2 (θ23) that is consistent with reactor experiments. 2PACS numbers: 14.60. Pq, 14.60.Lm, The neutrino oscillation phenomenon is successfully modeled by a theory of massive neutrino eigenstates that are different from the neutrino flavor eigenstates. These sets of eigenstates are related by the PMNS matrix [1] which is commonly parameterized by three angles, θ ij , and a CP-violating phase, δ.The values of θ 12 and θ 23 have been measured [2-4] with indications that θ 23 is not maximal [5][6][7]. The final angle, θ 13 , is now known to have a nonzero value from measurements by reactor experiments [8][9][10], the measurement by the T2K [11] accelerator experiment, and from earlier MINOS results [12,13].Despite these accomplishments, the value of δ is still unknown, as is the ordering of the neutrino masses, which is referred to as the neutrino mass hierarchy. Much of the attention in the neutrino community is now focused on resolving these unknowns. The mass hierarchy is not only a fundamental property of neutrinos but also has a direct impact on the ability of neutrinoless double beta decay searches to state definitively whether the neutrino is its own antiparticle [14]. Reactor experiments make a pure measurement of θ 13 , whereas the ν µ → ν e and ν µ →ν e appearance probabilities measured by accelerator experiments such as MINOS depend on the value of δ and sin 2 (θ 23 ). In addition, the long-baseline of MI-NOS means that interactions between neutrinos and the matter of the Earth make the appearance probabilities dependent on the neutrino mass hierarchy [15,16].We report the result from the search for ν e (ν e ) appearance in a ν µ (ν µ ) beam using the full MINOS data sample. This result uses an exposure of 10.6 × 10 20 protons-ontarget taken with a ν beam and an exposure of 3.3 × 10 20 protons-on-target taken with aν beam. The neutrino sample is 30% larger than the sample used for the previous MINOS results on this topic [13]. This analysis represents the first long-baseline search forν µ →ν e appearance and places new constraints on θ 13 and on a combination of δ, θ 23 , and the neutrino mass hierarchy.In the MINOS experiment [17], neutrino oscillation is studied with the NuMI beamline [18] by measuring neutrino interactions in two detectors. The Near Detector (ND), which has a fiducial mass of 29 tons, is at a distance of 1.04 km from the production target and is used to determine the composition of the beam before the neutrinos have oscillated. The Far Detector...

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.

Combined analysis of µ disappearance and µ e ν ν → ν appearance in MINOS using accelerator and atmospheric neutrinos Article (Published Version) http://sro.sussex.ac.uk Devenish, N E, Falk, E, Hartnell, J and The MINOS Collaboration, et al (2014) Combined analysis of νμ disappearance and νμ → νe appearance in MINOS using accelerator and atmospheric neutrinos. Physical Review Letters (PRL), 112 (19). This version is available from Sussex Research Online: http://sro.sussex.ac.uk/70068/ This document is made available in accordance with publisher policies and may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the URL above for details on accessing the published version. Copyright and reuse:Sussex Research Online is a digital repository of the research output of the University.Copyright and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable, the material made available in SRO has been checked for eligibility before being made available.Copies of full text items generally can be reproduced, displayed or performed and given to third parties in any format or medium for personal research or study, educational, or not-for-profit purposes without prior permission or charge, provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. We report on a new analysis of neutrino oscillations in MINOS using the complete set of accelerator and atmospheric data. The analysis combines the ν μ disappearance and ν e appearance data using the three-flavor PRL 112, 191801 (2014) PHYSICAL REVIEW LETTERS week ending

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/c 2 (99% C.L.).

10 ÿ3 eV 2 =c 4 and sin 2 2 > 0:87 at 68% confidence level.