Search for sterile neutrino mixing in the MINOS long-baseline experiment

Journal Article · Mon Mar 01 00:00:00 EST 2010 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.81.052004· OSTI ID:21409816

Adamson, P; Bock, G J; Boehnlein, D J; Bogert, D; Childress, S; Choudhary, B C; Harris, D; Hatcher, R; Hylen, J; James, C; Jensen, D; Koizumi, G; Kreymer, A; Lucas, P; Marchionni, A; Moore, C D; Morfin, J; Plunkett, R K; Rameika, R A; Rebel, B ^[1]

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1. Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

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 3.18x10{sup 20} protons on target in which neutrinos of energies between {approx}500 MeV and 120 GeV are produced predominantly as {nu}{sub {mu},} 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 {nu}{sub {mu}}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 {theta}{sub 24} and {theta}{sub 34} are constrained to be less than 11 deg. and 56 deg. 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 {tau}{sub 3}/m{sub 3}>2.1x10{sup -12} s/eV at 90% C.L.

• OSTI ID: 21409816
• Journal Information: Physical Review. D, Particles Fields, Vol. 81, Issue 5; Other Information: DOI: 10.1103/PhysRevD.81.052004; (c) 2010 The American Physical Society; ISSN 0556-2821
• Country of Publication: United States
• Language: English

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72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHARGED-CURRENT INTERACTIONS
COMPARATIVE EVALUATIONS
ENERGY SPECTRA
FLAVOR MODEL
GEV RANGE
LIFETIME
MEV RANGE 100-1000
MIXING
MUON NEUTRINOS
NEUTRAL CURRENTS
NEUTRAL-CURRENT INTERACTIONS
NEUTRINO BEAMS
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PARTICLE DECAY
PROTONS
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EVALUATION
FERMIONS
HADRONS
INTERACTIONS
LEPTON BEAMS
LEPTONS
MASSLESS PARTICLES
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MEV RANGE
NEUTRINOS
NUCLEONS
PARTICLE BEAMS
PARTICLE INTERACTIONS
PARTICLE MODELS
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