119 research outputs found
Simpatico
This is the catalogue of the exhibition "Simpatico" at Boston University Art Gallery
A Search for Electron Antineutrino Appearance at the 1 Scale
The MiniBooNE Collaboration reports initial results from a search for
oscillations. A signal-blind analysis was
performed using a data sample corresponding to protons on
target. The data are consistent with background prediction across the full
range of neutrino energy reconstructed assuming quasielastic scattering, MeV: 144 electron-like events have been observed in this
energy range, compared to an expectation of events. No
significant excess of events has been observed, both at low energy, 200-475
MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect
to antineutrino oscillations suggested by data from the Liquid Scintillator
Neutrino Detector at Los Alamos National Laboratory.Comment: 5 pages, 3 figures, 2 table
Measurement of the neutrino component of an anti-neutrino beam observed by a non-magnetized detector
Two independent methods are employed to measure the neutrino flux of the
anti-neutrino-mode beam observed by the MiniBooNE detector. The first method
compares data to simulated event rates in a high purity \numu induced
charged-current single \pip (CC1\pip) sample while the second exploits the
difference between the angular distributions of muons created in \numu and
\numub charged-current quasi-elastic (CCQE) interactions. The results from
both analyses indicate the prediction of the neutrino flux component of the
pre-dominately anti-neutrino beam is over-estimated - the CC1\pip analysis
indicates the predicted \numu flux should be scaled by , while
the CCQE angular fit yields . The energy spectrum of the flux
prediction is checked by repeating the analyses in bins of reconstructed
neutrino energy, and the results show that the spectral shape is well modeled.
These analyses are a demonstration of techniques for measuring the neutrino
contamination of anti-neutrino beams observed by future non-magnetized
detectors.Comment: 15 pages, 7 figures, published in Physical Review D, latest version
reflects changes from referee comment
Measurement of Muon Neutrino Quasi-Elastic Scattering on Carbon
The observation of neutrino oscillations is clear evidence for physics beyond
the standard model. To make precise measurements of this phenomenon, neutrino
oscillation experiments, including MiniBooNE, require an accurate description
of neutrino charged current quasi-elastic (CCQE) cross sections to predict
signal samples. Using a high-statistics sample of muon neutrino CCQE events,
MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments,
accurately characterizes the CCQE events observed in a carbon-based detector.
The extracted parameters include an effective axial mass, M_A^eff = 1.23+/-0.20
GeV, that describes the four-momentum dependence of the axial-vector form
factor of the nucleon; and a Pauli-suppression parameter, kappa =
1.019+/-0.011. Such a modified Fermi gas model may also be used by future
accelerator-based experiments measuring neutrino oscillations on nuclear
targets.Comment: 5 pages, 3 figure
Measurement of the \nu_\mu charged current \pi^+ to quasi-elastic cross section ratio on mineral oil in a 0.8 GeV neutrino beam
Using high statistics samples of charged current interactions,
MiniBooNE reports a measurement of the single charged pion production to
quasi-elastic cross section ratio on mineral oil (CH), both with and
without corrections for hadron re-interactions in the target nucleus. The
result is provided as a function of neutrino energy in the range 0.4 GeV 2.4 GeV with 11% precision in the region of highest statistics. The
results are consistent with previous measurements and the prediction from
historical neutrino calculations.Comment: 4 pages, 2 figure
First Observation of Coherent Production in Neutrino Nucleus Interactions with 2 GeV
The MiniBooNE experiment at Fermilab has amassed the largest sample to date
of s produced in neutral current (NC) neutrino-nucleus interactions at
low energy. This paper reports a measurement of the momentum distribution of
s produced in mineral oil (CH) and the first observation of coherent
production below 2 GeV. In the forward direction, the yield of events
observed above the expectation for resonant production is attributed primarily
to coherent production off carbon, but may also include a small contribution
from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino
flux, the sum of the NC coherent and diffractive modes is found to be (19.5
1.1 (stat) 2.5 (sys))% of all exclusive NC production at
MiniBooNE. These measurements are of immediate utility because they quantify an
important background to MiniBooNE's search for
oscillations.Comment: Submitted to Phys. Lett.
Event Excess in the MiniBooNE Search for Oscillations
The MiniBooNE experiment at Fermilab reports results from a search for oscillations, using a data sample corresponding
to protons on target. An excess of events
is observed in the energy range MeV, which, when
constrained by the observed events, has a probability for
consistency with the background-only hypothesis of 0.5\%. On the other hand,
fitting for oscillations, the best-fit
point has a -probability of 8.7\%. The data are consistent with oscillations in the 0.1 to 1.0 eV range and with the evidence for antineutrino oscillations from the Liquid
Scintillator Neutrino Detector at Los Alamos National Laboratory.Comment: Revised abstrac
First Measurement of and Events in an Off-Axis Horn-Focused Neutrino Beam
We report the first observation of off-axis neutrino interactions in the
MiniBooNE detector from the NuMI beamline at Fermilab. The MiniBooNE detector
is located 745 m from the NuMI production target, at 110 mrad angle
() with respect to the NuMI beam axis. Samples of charged current
quasi-elastic and interactions are analyzed and found to be
in agreement with expectation. This provides a direct verification of the
expected pion and kaon contributions to the neutrino flux and validates the
modeling of the NuMI off-axis beam.Comment: 4 pages, 5 figures, Submitted to Phys. Rev. Let
A Search for Electron Neutrino Appearance at the Delta m**2 ~ 1 eV**2 Scale
The MiniBooNE Collaboration reports first results of a search for
appearance in a beam. With two largely independent analyses, we
observe no significant excess of events above background for reconstructed
neutrino energies above 475 MeV. The data are consistent with no oscillations
within a two neutrino appearance-only oscillation model.Comment: 6 pages, 2 figure
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