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MiniBooNE and MicroBooNE Combined Fit to a 3+1 Sterile Neutrino Scenario
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
J. M. Conrad,
R. Dharmapalan,
A. Diaz,
Z. Djurcic,
D. A. Finley,
R. Ford,
G. T. Garvey,
S. Gollapinni,
A. Hourlier,
E. -C. Huang,
N. W. Kamp,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
K. Lin,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills,
J. Mirabal-Martinez,
C. D. Moore,
R. H. Nelson,
J. Nowak
, et al. (14 additional authors not shown)
Abstract:
This letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short-baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experim…
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This letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short-baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone, and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combined fit with the exclusive CCQE analysis (inclusive analysis) are $Δm^2 = 0.29 eV^2 (0.33 eV^2)$, $|U_{e4}|^2 = 0.016 (0.500)$, $|U_{μ4}|^2 = 0.500 (0.500)$, and $\sin^2(2θ_{μe})=0.0316 (1.0)$. Comparing the no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a $Δχ^2/\text{dof} = 24.7 / 3 (17.3 / 3)$, a $4.3σ(3.4σ)$ preference assuming the asymptotic approximation given by Wilks' theorem.
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Submitted 9 September, 2022; v1 submitted 5 January, 2022;
originally announced January 2022.
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MiniBooNE Data Releases
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
J. M. Conrad,
R. Dharmapalan,
A. Diaz,
Z. Djurcic,
D. A. Finley,
R. Ford,
G. T. Garvey,
S. Gollapinni,
A. Hourlier,
E. -C. Huang,
N. W. Kamp,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
K. Lin,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills,
J. Mirabal-Martinez,
C. D. Moore,
R. H. Nelson,
J. Nowak
, et al. (16 additional authors not shown)
Abstract:
The MiniBooNE experiment has provided data releases for most publications. Occasionally it is necessary to move data release pages. This document provides a single point of reference that will be updated by the collaboration to point to the present location of the MiniBooNE data releases.
The MiniBooNE experiment has provided data releases for most publications. Occasionally it is necessary to move data release pages. This document provides a single point of reference that will be updated by the collaboration to point to the present location of the MiniBooNE data releases.
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Submitted 25 October, 2021;
originally announced October 2021.
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Updated MiniBooNE Neutrino Oscillation Results with Increased Data and New Background Studies
Authors:
MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
B. C. Brown,
J. M. Conrad,
R. Dharmapalan,
A. Diaz,
Z. Djurcic,
D. A. Finley,
R. Ford,
G. T. Garvey,
S. Gollapinni,
A. Hourlier,
E. C. Huang,
N. W. Kamp,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
K. Lin,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills,
J. Mirabal-Martinez,
C. D. Moore,
R. H. Nelson
, et al. (17 additional authors not shown)
Abstract:
The MiniBooNE experiment at Fermilab reports a total excess of $638.0 \pm 132.8$ electron-like events ($4.8 σ$) from a data sample corresponding to $18.75 \times 10^{20}$ protons-on-target in neutrino mode, which is a 46\% increase in the data sample with respect to previously published results, and $11.27 \times 10^{20}$ protons-on-target in antineutrino mode. The additional statistics allow seve…
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The MiniBooNE experiment at Fermilab reports a total excess of $638.0 \pm 132.8$ electron-like events ($4.8 σ$) from a data sample corresponding to $18.75 \times 10^{20}$ protons-on-target in neutrino mode, which is a 46\% increase in the data sample with respect to previously published results, and $11.27 \times 10^{20}$ protons-on-target in antineutrino mode. The additional statistics allow several studies to address questions on the source of the excess. First, we provide two-dimensional plots in visible energy and cosine of the angle of the outgoing lepton, which can provide valuable input to models for the event excess. Second, we test whether the excess may arise from photons that enter the detector from external events or photons exiting the detector from $π^0$ decays in two model independent ways. Beam timing information shows that almost all of the excess is in time with neutrinos that interact in the detector. The radius distribution shows that the excess is distributed throughout the volume, while tighter cuts on the fiducal volume increase the significance of the excess. We conclude that models of the event excess based on entering and exiting photons are disfavored.
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Submitted 8 March, 2021; v1 submitted 30 June, 2020;
originally announced June 2020.
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Dark Matter Search in Nucleon, Pion, and Electron Channels from a Proton Beam Dump with MiniBooNE
Authors:
MiniBooNE-DM Collaboration,
A. A. Aguilar-Arevalo,
M. Backfish,
A. Bashyal,
B. Batell,
B. C. Brown,
R. Carr,
A. Chatterjee,
R. L. Cooper,
P. deNiverville,
R. Dharmapalan,
Z. Djurcic,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
J. A. Green,
E. -C. Huang,
W. Huelsnitz,
I. L. de Icaza Astiz,
G. Karagiorgi,
T. Katori,
W. Ketchum,
T. Kobilarcik,
Q. Liu
, et al. (20 additional authors not shown)
Abstract:
A search for sub-GeV dark matter produced from collisions of the Fermilab 8 GeV Booster protons with a steel beam dump was performed by the MiniBooNE-DM Collaboration using data from $1.86 \times 10^{20}$ protons on target in a dedicated run. The MiniBooNE detector, consisting of 818 tons of mineral oil and located 490 meters downstream of the beam dump, is sensitive to a variety of dark matter in…
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A search for sub-GeV dark matter produced from collisions of the Fermilab 8 GeV Booster protons with a steel beam dump was performed by the MiniBooNE-DM Collaboration using data from $1.86 \times 10^{20}$ protons on target in a dedicated run. The MiniBooNE detector, consisting of 818 tons of mineral oil and located 490 meters downstream of the beam dump, is sensitive to a variety of dark matter initiated scattering reactions. Three dark matter interactions are considered for this analysis: elastic scattering off nucleons, inelastic neutral pion production, and elastic scattering off electrons. Multiple data sets were used to constrain flux and systematic errors, and time-of-flight information was employed to increase sensitivity to higher dark matter masses. No excess from the background predictions was observed, and 90$\%$ confidence level limits were set on the vector portal and leptophobic dark matter models. New parameter space is excluded in the vector portal dark matter model with a dark matter mass between 5 and 50$\,\mathrm{MeV}\,c^{-2}$. The reduced neutrino flux allowed to test if the MiniBooNE neutrino excess scales with the production of neutrinos. No excess of neutrino oscillation events were measured ruling out models that scale solely by number of protons on target independent of beam configuration at 4.6$σ$.
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Submitted 29 March, 2019; v1 submitted 16 July, 2018;
originally announced July 2018.
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Significant Excess of ElectronLike Events in the MiniBooNE Short-Baseline Neutrino Experiment
Authors:
MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
J. M. Conrad,
R. L. Cooper,
R. Dharmapalan,
A. Diaz,
Z. Djurcic,
D. A. Finley,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
E. -C. Huang,
W. Huelsnitz,
C. Ignarra,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
C. Mariani,
W. Marsh
, et al. (23 additional authors not shown)
Abstract:
The MiniBooNE experiment at Fermilab reports results from an analysis of $ν_e$ appearance data from $12.84 \times 10^{20}$ protons on target in neutrino mode, an increase of approximately a factor of two over previously reported results. A $ν_e$ charged-current quasielastic event excess of $381.2 \pm 85.2$ events ($4.5 σ$) is observed in the energy range $200<E_ν^{QE}<1250$~MeV. Combining these da…
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The MiniBooNE experiment at Fermilab reports results from an analysis of $ν_e$ appearance data from $12.84 \times 10^{20}$ protons on target in neutrino mode, an increase of approximately a factor of two over previously reported results. A $ν_e$ charged-current quasielastic event excess of $381.2 \pm 85.2$ events ($4.5 σ$) is observed in the energy range $200<E_ν^{QE}<1250$~MeV. Combining these data with the $\bar ν_e$ appearance data from $11.27 \times 10^{20}$ protons on target in antineutrino mode, a total $ν_e$ plus $\bar ν_e$ charged-current quasielastic event excess of $460.5 \pm 99.0$ events ($4.7 σ$) is observed. If interpreted in a two-neutrino oscillation model, $ν_μ \rightarrow ν_e$, the best oscillation fit to the excess has a probability of $21.1\%$, while the background-only fit has a $χ^2$ probability of $6 \times 10^{-7}$ relative to the best fit. The MiniBooNE data are consistent in energy and magnitude with the excess of events reported by the Liquid Scintillator Neutrino Detector (LSND), and the significance of the combined LSND and MiniBooNE excesses is $6.0 σ$. A two-neutrino oscillation interpretation of the data would require at least four neutrino types and indicate physics beyond the three neutrino paradigm.Although the data are fit with a two-neutrino oscillation model, other models may provide better fits to the data.
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Submitted 26 October, 2018; v1 submitted 30 May, 2018;
originally announced May 2018.
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First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
E. D. Church,
J. M. Conrad,
R. L. Cooper,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
R. S. Fitzpatrick,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
W. Huelsnitz,
C. Ignarra,
R. Imlay,
R. A. Johnson,
J. R. Jordan,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
K. Mahn
, et al. (24 additional authors not shown)
Abstract:
We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest ($K^+ \rightarrow μ^+ ν_μ$) at the NuMI beamline absorber. These signal $ν_μ$-carbon events are distinguished from primarily pion decay in flight $ν_μ$ and $\overlineν_μ$ backgrounds produced at the target stati…
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We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest ($K^+ \rightarrow μ^+ ν_μ$) at the NuMI beamline absorber. These signal $ν_μ$-carbon events are distinguished from primarily pion decay in flight $ν_μ$ and $\overlineν_μ$ backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9$σ$ level. The muon kinetic energy, neutrino-nucleus energy transfer ($ω=E_ν-E_μ$), and total cross section for these events is extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of $ω$ using neutrinos, a quantity thus far only accessible through electron scattering.
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Submitted 7 May, 2018; v1 submitted 11 January, 2018;
originally announced January 2018.
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Dark Matter Search in a Proton Beam Dump with MiniBooNE
Authors:
A. A. Aguilar-Arevalo,
M. Backfish,
A. Bashyal,
B. Batell,
B. C. Brown,
R. Carr,
A. Chatterjee,
R. L. Cooper,
P. deNiverville,
R. Dharmapalan,
Z. Djurcic,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
J. A. Green,
W. Huelsnitz,
I. L. de Icaza Astiz,
G. Karagiorgi,
T. Katori,
W. Ketchum,
T. Kobilarcik,
Q. Liu,
W. C. Louis,
W. Marsh
, et al. (18 additional authors not shown)
Abstract:
The MiniBooNE-DM collaboration searched for vector-boson mediated production of dark matter using the Fermilab 8 GeV Booster proton beam in a dedicated run with $1.86 \times 10^{20}$ protons delivered to a steel beam dump. The MiniBooNE detector, 490~m downstream, is sensitive to dark matter via elastic scattering with nucleons in the detector mineral oil. Analysis methods developed for previous M…
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The MiniBooNE-DM collaboration searched for vector-boson mediated production of dark matter using the Fermilab 8 GeV Booster proton beam in a dedicated run with $1.86 \times 10^{20}$ protons delivered to a steel beam dump. The MiniBooNE detector, 490~m downstream, is sensitive to dark matter via elastic scattering with nucleons in the detector mineral oil. Analysis methods developed for previous MiniBooNE scattering results were employed, and several constraining data sets were simultaneously analyzed to minimize systematic errors from neutrino flux and interaction rates. No excess of events over background was observed, leading to a 90\% confidence limit on the dark-matter cross section parameter, $Y=ε^2α_D(m_χ/m_V)^4 \lesssim10^{-8}$, for $α_D=0.5$ and for dark-matter masses of $0.01<m_χ<0.3~\mathrm{GeV}$ in a vector portal model of dark matter. This is the best limit from a dedicated proton beam dump search in this mass and coupling range and extends below the mass range of direct dark matter searches. These results demonstrate a novel and powerful approach to dark matter searches with beam dump experiments.
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Submitted 23 August, 2017; v1 submitted 8 February, 2017;
originally announced February 2017.
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Density vs distance for the DUNE beam from two recent geology density maps
Authors:
Byron P. Roe
Abstract:
The densities passed through for neutrinos going from Fermilab to Sanford lab are obtained using two recent density tables, crustal [1] and Shen-Ritzwoller[2], as well as the values from an older table PEMC[3].
The densities passed through for neutrinos going from Fermilab to Sanford lab are obtained using two recent density tables, crustal [1] and Shen-Ritzwoller[2], as well as the values from an older table PEMC[3].
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Submitted 12 August, 2016;
originally announced August 2016.
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Using L/E Oscillation Probability Distributions
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
E. D. Church,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
W. Huelsnitz,
C. Ignarra,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills,
J. Mirabal
, et al. (19 additional authors not shown)
Abstract:
This paper explores the use of $L/E$ oscillation probability distributions to compare experimental measurements and to evaluate oscillation models. In this case, $L$ is the distance of neutrino travel and $E$ is a measure of the interacting neutrino's energy. While comparisons using allowed and excluded regions for oscillation model parameters are likely the only rigorous method for these comparis…
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This paper explores the use of $L/E$ oscillation probability distributions to compare experimental measurements and to evaluate oscillation models. In this case, $L$ is the distance of neutrino travel and $E$ is a measure of the interacting neutrino's energy. While comparisons using allowed and excluded regions for oscillation model parameters are likely the only rigorous method for these comparisons, the $L/E$ distributions are shown to give qualitative information on the agreement of an experiment's data with a simple two-neutrino oscillation model. In more detail, this paper also outlines how the $L/E$ distributions can be best calculated and used for model comparisons. Specifically, the paper presents the $L/E$ data points for the final MiniBooNE data samples and, in the Appendix, explains and corrects the mistaken analysis published by the ICARUS collaboration.
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Submitted 11 July, 2014;
originally announced July 2014.
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A new investigation of electron neutrino appearance oscillations with improved sensitivity in the MiniBooNE+ experiment
Authors:
R. Dharmapalan,
S. Habib,
C. Jiang,
I. Stancu,
Z. Djurcic,
R. A. Johnson,
A. Wickremasinghe,
G. Karagiorgi,
M. H. Shaevitz,
B. C. Brown,
F. G. Garcia,
R. Ford,
W. Marsh,
C. D. Moore,
D. Perevalov,
C. C. Polly,
J. Grange,
J. Mousseau,
B. Osmanov,
H. Ray,
R. Cooper,
R. Tayloe,
R. Thornton,
G. T. Garvey,
W. Huelsnitz
, et al. (12 additional authors not shown)
Abstract:
We propose the addition of scintillator to the existing MiniBooNE detector to allow a test of the neutral-current/charged-current (NC/CC) nature of the MiniBooNE low-energy excess. Scintillator will enable the reconstruction of 2.2 MeV $γ$s from neutron-capture on protons following neutrino interactions. Low-energy CC interactions where the oscillation excess is observed should have associated neu…
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We propose the addition of scintillator to the existing MiniBooNE detector to allow a test of the neutral-current/charged-current (NC/CC) nature of the MiniBooNE low-energy excess. Scintillator will enable the reconstruction of 2.2 MeV $γ$s from neutron-capture on protons following neutrino interactions. Low-energy CC interactions where the oscillation excess is observed should have associated neutrons with less than a 10% probability. This is in contrast to the NC backgrounds that should have associated neutrons in approximately 50% of events. We will measure these neutron fractions with $ν_μ$ CC and NC events to eliminate that systematic uncertainty. This neutron-fraction measurement requires $6.5\times10^{20}$ protons on target delivered to MiniBooNE with scintillator added in order to increase the significance of an oscillation excess to over $5σ$.
This new phase of MiniBooNE will also enable additional important studies such as the spin structure of nucleon ($Δs$) via NC elastic scattering, a low-energy measurement of the neutrino flux via $\numu ^{12}C \rightarrow μ^{-} ^{12}N_\textrm{g.s.}$ scattering, and a test of the quasielastic assumption in neutrino energy reconstruction. These topics will yield important, highly-cited results over the next 5 years for a modest cost, and will help to train Ph.D. students and postdocs. This enterprise offers complementary information to that from the upcoming liquid Argon based MicroBooNE experiment. In addition, MicroBooNE is scheduled to receive neutrinos in early 2014, and there is minimal additional cost to also deliver beam to MiniBooNE.
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Submitted 2 October, 2013; v1 submitted 30 September, 2013;
originally announced October 2013.
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Measurement of the Antineutrino Neutral-Current Elastic Differential Cross Section
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
E. D. Church,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
W. Huelsnitz,
C. Ignarra,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills,
J. Mirabal
, et al. (20 additional authors not shown)
Abstract:
We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section ($dσ_{\bar νN \rightarrow \bar νN}/dQ^{2}$) on CH$_{2}$ by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of an…
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We report the measurement of the flux-averaged antineutrino neutral current elastic scattering cross section ($dσ_{\bar νN \rightarrow \bar νN}/dQ^{2}$) on CH$_{2}$ by the MiniBooNE experiment using the largest sample of antineutrino neutral current elastic candidate events ever collected. The ratio of the antineutrino to neutrino neutral current elastic scattering cross sections and a ratio of antineutrino neutral current elastic to antineutrino charged current quasi elastic cross section is also presented.
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Submitted 27 September, 2013;
originally announced September 2013.
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The OscSNS White Paper
Authors:
OscSNS Collaboration,
R. Allen,
F. T. Avignone,
J. Boissevain,
Y. Efremenko,
M. Elnimr,
T. Gabriel,
F. G. Garcia,
G. T. Garvey,
T. Handler,
W. Huelsnitz,
R. Imlay,
Y. Kamyshkov,
J. M. Link,
W. C. Louis,
G. B. Mills,
S. R. Mishra,
B. Osmanov,
Z. Pavlovic,
H. Ray,
B. P. Roe,
C. Rosenfeld,
I. Stancu,
R. Svoboda,
R. Tayloe
, et al. (4 additional authors not shown)
Abstract:
There exists a need to address and resolve the growing evidence for short-baseline neutrino oscillations and the possible existence of sterile neutrinos. Such non-standard particles require a mass of $\sim 1$ eV/c$^2$, far above the mass scale associated with active neutrinos, and were first invoked to explain the LSND $\bar ν_μ\rightarrow \bar ν_e$ appearance signal. More recently, the MiniBooNE…
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There exists a need to address and resolve the growing evidence for short-baseline neutrino oscillations and the possible existence of sterile neutrinos. Such non-standard particles require a mass of $\sim 1$ eV/c$^2$, far above the mass scale associated with active neutrinos, and were first invoked to explain the LSND $\bar ν_μ\rightarrow \bar ν_e$ appearance signal. More recently, the MiniBooNE experiment has reported a $2.8 σ$ excess of events in antineutrino mode consistent with neutrino oscillations and with the LSND antineutrino appearance signal. MiniBooNE also observed a $3.4 σ$ excess of events in their neutrino mode data. Lower than expected neutrino-induced event rates using calibrated radioactive sources and nuclear reactors can also be explained by the existence of sterile neutrinos. Fits to the world's neutrino and antineutrino data are consistent with sterile neutrinos at this $\sim 1$ eV/c$^2$ mass scale, although there is some tension between measurements from disappearance and appearance experiments. In addition to resolving this potential major extension of the Standard Model, the existence of sterile neutrinos will impact design and planning for all future neutrino experiments. It should be an extremely high priority to conclusively establish if such unexpected light sterile neutrinos exist. The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory, built to usher in a new era in neutron research, provides a unique opportunity for US science to perform a definitive world-class search for sterile neutrinos.
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Submitted 7 October, 2013; v1 submitted 26 July, 2013;
originally announced July 2013.
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Improved Search for $\bar ν_μ\rightarrow \bar ν_e$ Oscillations in the MiniBooNE Experiment
Authors:
The MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
E. D. Church,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
W. Huelsnitz,
C. Ignarra,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills
, et al. (20 additional authors not shown)
Abstract:
The MiniBooNE experiment at Fermilab reports results from an analysis of $\bar ν_e$ appearance data from $11.27 \times 10^{20}$ protons on target in antineutrino mode, an increase of approximately a factor of two over the previously reported results. An event excess of $78.4 \pm 28.5$ events ($2.8 σ$) is observed in the energy range $200<E_ν^{QE}<1250$ MeV. If interpreted in a two-neutrino oscilla…
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The MiniBooNE experiment at Fermilab reports results from an analysis of $\bar ν_e$ appearance data from $11.27 \times 10^{20}$ protons on target in antineutrino mode, an increase of approximately a factor of two over the previously reported results. An event excess of $78.4 \pm 28.5$ events ($2.8 σ$) is observed in the energy range $200<E_ν^{QE}<1250$ MeV. If interpreted in a two-neutrino oscillation model, $\barν_μ\rightarrow\barν_e$, the best oscillation fit to the excess has a probability of 66% while the background-only fit has a $χ^2$-probability of 0.5% relative to the best fit. The data are consistent with antineutrino oscillations in the $0.01 < Δm^2 < 1.0$ eV$^2$ range and have some overlap with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector (LSND). All of the major backgrounds are constrained by in-situ event measurements so non-oscillation explanations would need to invoke new anomalous background processes. The neutrino mode running also shows an excess at low energy of $162.0 \pm 47.8$ events ($3.4 σ$) but the energy distribution of the excess is marginally compatible with a simple two neutrino oscillation formalism. Expanded models with several sterile neutrinos can reduce the incompatibility by allowing for CP violating effects between neutrino and antineutrino oscillations.
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Submitted 12 March, 2013; v1 submitted 11 March, 2013;
originally announced March 2013.
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First Measurement of the Muon Anti-Neutrino Double-Differential Charged Current Quasi-Elastic Cross Section
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
E. D. Church,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
W. Huelsnitz,
C. Ignarra,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills,
J. Mirabal
, et al. (20 additional authors not shown)
Abstract:
The largest sample ever recorded of $\numub$ charged-current quasi-elastic (CCQE, $\numub + p \to \mup + n$) candidate events is used to produce the minimally model-dependent, flux-integrated double-differential cross section $\frac{d^{2}σ}{dT_μd\uz}$ for $\numub$ incident on mineral oil. This measurement exploits the unprecedented statistics of the MiniBooNE anti-neutrino mode sample and provides…
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The largest sample ever recorded of $\numub$ charged-current quasi-elastic (CCQE, $\numub + p \to \mup + n$) candidate events is used to produce the minimally model-dependent, flux-integrated double-differential cross section $\frac{d^{2}σ}{dT_μd\uz}$ for $\numub$ incident on mineral oil. This measurement exploits the unprecedented statistics of the MiniBooNE anti-neutrino mode sample and provides the most complete information of this process to date. Also given to facilitate historical comparisons are the flux-unfolded total cross section $σ(E_ν)$ and single-differential cross section $\frac{dσ}{d\qsq}$ on both mineral oil and on carbon by subtracting the $\numub$ CCQE events on hydrogen. The observed cross section is somewhat higher than the predicted cross section from a model assuming independently-acting nucleons in carbon with canonical form factor values. The shape of the data are also discrepant with this model. These results have implications for intra-nuclear processes and can help constrain signal and background processes for future neutrino oscillation measurements.
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Submitted 4 August, 2013; v1 submitted 29 January, 2013;
originally announced January 2013.
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Low Mass WIMP Searches with a Neutrino Experiment: A Proposal for Further MiniBooNE Running
Authors:
A. A. Aguilar-Arevalo,
B. Batell,
R. Cooper,
P. deNiverville,
R. Dharmapalan,
Z. Djurcic,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
S. Habib,
W. Huelsnitz,
C. Jiang,
R. A. Johnson,
W. Ketchum,
T. Kobilarcik,
W. C. Louis,
W. Marsh,
D. McKeen,
G. B. Mills,
J. Mirabal,
C. D. Moore,
P. Nienaber,
Z. Pavlovic,
D. Perevalov
, et al. (8 additional authors not shown)
Abstract:
A proposal submitted to the FNAL PAC is described to search for light sub-GeV WIMP dark matter at MiniBooNE. The possibility to steer the beam past the target and into an absorber leads to a significant reduction in neutrino background, allowing for a sensitive search for elastic scattering of WIMPs off nucleons or electrons in the detector. Dark matter models involving a vector mediator can be pr…
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A proposal submitted to the FNAL PAC is described to search for light sub-GeV WIMP dark matter at MiniBooNE. The possibility to steer the beam past the target and into an absorber leads to a significant reduction in neutrino background, allowing for a sensitive search for elastic scattering of WIMPs off nucleons or electrons in the detector. Dark matter models involving a vector mediator can be probed in a parameter region consistent with the required thermal relic density, and which overlaps the region in which these models can resolve the muon g-2 discrepancy. Estimates of signal significance are presented for various operational modes and parameter points. The experimental approach outlined for applying MiniBooNE to a light WIMP search may also be applicable to other neutrino facilities.
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Submitted 9 November, 2012;
originally announced November 2012.
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Letter of Intent: A new investigation of numu to nue oscillations with improved sensitivity in an enhanced MiniBooNE experiment
Authors:
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
R. Cooper,
J. M. Conrad,
R. Dharmapalan,
R. Ford,
Z. Djurcic,
F. G. Garcia,
G. T. Garvey,
J. Grange,
S. Habib,
W. Huelsnitz,
R. Imlay,
C. Jiang,
G. Karagiorgi,
W. C. Louis,
R. A. Johnson,
W. Marsh,
C. Mauger,
G. B. Mills,
C. D. Moore,
J. Mousseau,
P. Nienaber,
B. Osmanov
, et al. (11 additional authors not shown)
Abstract:
We propose adding 300 mg/l PPO to the existing MiniBooNE detector mineral oil to increase the scintillation response. This will allow the detection of associated neutrons and increase sensitivity to final-state nucleons in neutrino interactions. This increased capability will enable an independent test of whether the current excess seen in the MiniBooNE oscillation search is signal or background.…
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We propose adding 300 mg/l PPO to the existing MiniBooNE detector mineral oil to increase the scintillation response. This will allow the detection of associated neutrons and increase sensitivity to final-state nucleons in neutrino interactions. This increased capability will enable an independent test of whether the current excess seen in the MiniBooNE oscillation search is signal or background. In addition it will enable other neutrino interaction measurements to be made including a search for the strange-quark contribution to the nucleon spin Delta s and a low-energy measurement of charged-current quasielastic scattering.
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Submitted 8 October, 2012;
originally announced October 2012.
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Dual baseline search for muon antineutrino disappearance at 0.1 eV^2 < Δm^2 < 100 eV^2
Authors:
MiniBooNE Collaboration,
SciBooNE Collaboration,
G. Cheng,
W. Huelsnitz,
A. A. Aguilar-Arevalo,
J. L. Alcaraz-Aunion,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Catala-Perez,
E. D. Church,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
U. Dore,
D. A. Finley,
R. Ford,
A. J. Franke,
F. G. Garcia,
G. T. Garvey,
C. Giganti,
J. J. Gomez-Cadenas,
J. Grange,
P. Guzowski,
A. Hanson
, et al. (66 additional authors not shown)
Abstract:
The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of \bar{ν_μ} at Fermilab's Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their datasets serves to partially constrain some of the flux and cross section uncertain…
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The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of \bar{ν_μ} at Fermilab's Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their datasets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the ν_μ background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on \bar{ν_μ} disappearance that dramatically improves upon prior limits in the Δm^2=0.1-100 eV^2 region.
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Submitted 5 November, 2012; v1 submitted 1 August, 2012;
originally announced August 2012.
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A Combined $ν_μ\to ν_e$ and $\barν_μ\to \barν_e$ Oscillation Analysis of the MiniBooNE Excesses
Authors:
MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
B. C. Brown,
L. Bugel,
G. Cheng,
E. D. Church,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
W. Huelsnitz,
C. Ignarra,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
W. C. Louis,
C. Mariani,
W. Marsh,
G. B. Mills
, et al. (20 additional authors not shown)
Abstract:
The MiniBooNE experiment at Fermilab reports results from an analysis of the combined $ν_e$ and $\bar ν_e$ appearance data from $6.46 \times 10^{20}$ protons on target in neutrino mode and $11.27 \times 10^{20}$ protons on target in antineutrino mode. A total excess of $240.3 \pm 34.5 \pm 52.6$ events ($3.8 σ$) is observed from combining the two data sets in the energy range $200<E_ν^{QE}<1250$ Me…
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The MiniBooNE experiment at Fermilab reports results from an analysis of the combined $ν_e$ and $\bar ν_e$ appearance data from $6.46 \times 10^{20}$ protons on target in neutrino mode and $11.27 \times 10^{20}$ protons on target in antineutrino mode. A total excess of $240.3 \pm 34.5 \pm 52.6$ events ($3.8 σ$) is observed from combining the two data sets in the energy range $200<E_ν^{QE}<1250$ MeV. In a combined fit for CP-conserving $ν_μ\rightarrow ν_e$ and $\barν_μ\rightarrow\barν_e$ oscillations via a two-neutrino model, the background-only fit has a $χ^2$-probability of 0.03% relative to the best oscillation fit. The data are consistent with neutrino oscillations in the $0.01 < Δm^2 < 1.0$ eV$^2$ range and with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector (LSND).
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Submitted 27 August, 2012; v1 submitted 19 July, 2012;
originally announced July 2012.
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Test of Lorentz and CPT violation with Short Baseline Neutrino Oscillation Excesses
Authors:
The MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
W. Huelsnitz
, et al. (63 additional authors not shown)
Abstract:
The sidereal time dependence of MiniBooNE electron neutrino and anti-electron neutrino appearance data are analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov-Smirnov test shows both the electron neutrino and anti-electron neutrino appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lor…
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The sidereal time dependence of MiniBooNE electron neutrino and anti-electron neutrino appearance data are analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov-Smirnov test shows both the electron neutrino and anti-electron neutrino appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lorentz-violating oscillation model derived from the Standard Model Extension (SME) to describe any excess events over background, we find that the electron neutrino appearance data prefer a sidereal time-independent solution, and the anti-electron neutrino appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10E-20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for muon neutrino to electron neutrino and anti-muon neutrino to anti-electron neutrino oscillations. The fit values and limits of combinations of SME coefficients are provided.
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Submitted 22 June, 2012; v1 submitted 15 September, 2011;
originally announced September 2011.
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Dual baseline search for muon neutrino disappearance at 0.5 eV^2 < Δm^2 < 40 eV^2
Authors:
MiniBooNE,
SciBooNE Collaborations,
:,
K. B. M. Mahn,
Y. Nakajima,
A. A. Aguilar-Arevalo,
J. L. Alcaraz-Aunion,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
J. Catala-Perez,
G. Cheng,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
R. Dharmapalan,
Z. Djurcic,
U. Dore,
D. A. Finley,
B. T. Fleming,
R. Ford
, et al. (105 additional authors not shown)
Abstract:
The SciBooNE and MiniBooNE collaborations report the results of a ν_μdisappearance search in the Δm^2 region of 0.5-40 eV^2. The neutrino rate as measured by the SciBooNE tracking detectors is used to constrain the rate at the MiniBooNE Cherenkov detector in the first joint analysis of data from both collaborations. Two separate analyses of the combined data samples set 90% confidence level (CL) l…
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The SciBooNE and MiniBooNE collaborations report the results of a ν_μdisappearance search in the Δm^2 region of 0.5-40 eV^2. The neutrino rate as measured by the SciBooNE tracking detectors is used to constrain the rate at the MiniBooNE Cherenkov detector in the first joint analysis of data from both collaborations. Two separate analyses of the combined data samples set 90% confidence level (CL) limits on ν_μdisappearance in the 0.5-40 eV^2 Δm^2 region, with an improvement over previous experimental constraints between 10 and 30 eV^2.
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Submitted 28 December, 2011; v1 submitted 28 June, 2011;
originally announced June 2011.
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Measurement of the neutrino component of an anti-neutrino beam observed by a non-magnetized detector
Authors:
A. A. Aguilar-Arevalo,
C. E. Anderson,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. M. Conrad,
R. Dharmapalan,
Z. Djurcic,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
J. A. Green,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
T. Katori,
T. Kobilarcik,
S. K. Linden,
W. C. Louis,
K. B. M. Mahn,
W. Marsh,
C. Mauger,
W. Metcalf
, et al. (29 additional authors not shown)
Abstract:
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-curre…
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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 $0.76 \pm 0.11$, while the CCQE angular fit yields $0.65 \pm 0.23$. 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.
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Submitted 29 January, 2013; v1 submitted 9 February, 2011;
originally announced February 2011.
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Measurement of Neutrino-Induced Charged-Current Charged Pion Production Cross Sections on Mineral Oil at E$_ν\sim 1~\textrm{GeV}$
Authors:
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
R. Imlay,
R. A. Johnson
, et al. (61 additional authors not shown)
Abstract:
Using a high-statistics, high-purity sample of $ν_μ$-induced charged current, charged pion events in mineral oil (CH$_2$), MiniBooNE reports a collection of interaction cross sections for this process. This includes measurements of the CC$π^+$ cross section as a function of neutrino energy, as well as flux-averaged single- and double-differential cross sections of the energy and direction of both…
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Using a high-statistics, high-purity sample of $ν_μ$-induced charged current, charged pion events in mineral oil (CH$_2$), MiniBooNE reports a collection of interaction cross sections for this process. This includes measurements of the CC$π^+$ cross section as a function of neutrino energy, as well as flux-averaged single- and double-differential cross sections of the energy and direction of both the final-state muon and pion. In addition, each of the single-differential cross sections are extracted as a function of neutrino energy to decouple the shape of the MiniBooNE energy spectrum from the results. In many cases, these cross sections are the first time such quantities have been measured on a nuclear target and in the 1 GeV energy range.
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Submitted 31 March, 2011; v1 submitted 15 November, 2010;
originally announced November 2010.
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Measurement of $ν_μ$-induced charged-current neutral pion production cross sections on mineral oil at $E_ν\in0.5-2.0$ GeV
Authors:
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
R. Dharmapalan,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
R. Imlay,
R. A. Johnson
, et al. (61 additional authors not shown)
Abstract:
Using a custom 3 Čerenkov-ring fitter, we report cross sections for $ν_μ$-induced charged-current single $π^0$ production on mineral oil (\chtwo) from a sample of 5810 candidate events with 57% signal purity over an energy range of $0.5-2.0$GeV. This includes measurements of the absolute total cross section as a function of neutrino energy, and flux-averaged differential cross sections measured in…
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Using a custom 3 Čerenkov-ring fitter, we report cross sections for $ν_μ$-induced charged-current single $π^0$ production on mineral oil (\chtwo) from a sample of 5810 candidate events with 57% signal purity over an energy range of $0.5-2.0$GeV. This includes measurements of the absolute total cross section as a function of neutrino energy, and flux-averaged differential cross sections measured in terms of $Q^2$, $μ^-$ kinematics, and $π^0$ kinematics. The sample yields a flux-averaged total cross section of $(9.2\pm0.3_{stat.}\pm1.5_{syst.})\times10^{-39}$cm$^2$/CH$_2$ at mean neutrino energy of 0.965GeV.
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Submitted 10 February, 2011; v1 submitted 15 October, 2010;
originally announced October 2010.
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First Measurement of the Muon Neutrino Charged Current Quasielastic Double Differential Cross Section
Authors:
MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Grange,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
R. Imlay,
R. A. Johnson
, et al. (61 additional authors not shown)
Abstract:
A high-statistics sample of charged-current muon neutrino scattering events collected with the MiniBooNE experiment is analyzed to extract the first measurement of the double differential cross section ($\frac{d^2σ}{dT_μd\cosθ_μ}$) for charged-current quasielastic (CCQE) scattering on carbon. This result features minimal model dependence and provides the most complete information on this process t…
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A high-statistics sample of charged-current muon neutrino scattering events collected with the MiniBooNE experiment is analyzed to extract the first measurement of the double differential cross section ($\frac{d^2σ}{dT_μd\cosθ_μ}$) for charged-current quasielastic (CCQE) scattering on carbon. This result features minimal model dependence and provides the most complete information on this process to date. With the assumption of CCQE scattering, the absolute cross section as a function of neutrino energy ($σ[E_ν]$) and the single differential cross section ($\frac{dσ}{dQ^2}$) are extracted to facilitate comparison with previous measurements. These quantities may be used to characterize an effective axial-vector form factor of the nucleon and to improve the modeling of low-energy neutrino interactions on nuclear targets. The results are relevant for experiments searching for neutrino oscillations.
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Submitted 29 July, 2010; v1 submitted 12 February, 2010;
originally announced February 2010.
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Measurement of ν_μand \barν_μinduced neutral current single $π^0$ production cross sections on mineral oil at E_νO(1 GeV)
Authors:
The MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
J. Gonzales,
J. Grange,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
R. Imlay
, et al. (62 additional authors not shown)
Abstract:
MiniBooNE reports the first absolute cross sections for neutral current single π^0 production on CH_2 induced by neutrino and antineutrino interactions measured from the largest sets of NC π^0 events collected to date. The principal result consists of differential cross sections measured as functions of π^0 momentum and π^0 angle averaged over the neutrino flux at MiniBooNE. We find total cross…
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MiniBooNE reports the first absolute cross sections for neutral current single π^0 production on CH_2 induced by neutrino and antineutrino interactions measured from the largest sets of NC π^0 events collected to date. The principal result consists of differential cross sections measured as functions of π^0 momentum and π^0 angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76+/-0.05_{stat}+/-0.76_{sys})*10^{-40} cm^2/nucleon at a mean energy of <E_ν>=808 MeV and (1.48+/-0.05_{stat}+/-0.23_{sys})*10^{-40} cm^2/nucleon at a mean energy of <E_ν>=664 MeV for ν_μand \barν_μinduced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1π^0 production corrected for the effects of final state interactions to compare to prior results.
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Submitted 27 January, 2010; v1 submitted 11 November, 2009;
originally announced November 2009.
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A Letter of Intent to Build a MiniBooNE Near Detector: BooNE
Authors:
I. Stancu,
Z. Djurcic,
D. Smith,
R. Ford,
T. Kobilarcik,
W. Marsh,
C. D. Moore,
J. Grange,
B. Osmanov,
H. Ray,
G. T. Garvey,
J. A. Green,
W. C. Louis,
C. Mauger,
G. B. Mills,
Z. Pavlovic,
R. Van de Water,
D. H. White,
G. P. Zeller,
W. Metcalf,
B. P. Roe,
A. A. Aguilar-Arevalo
Abstract:
There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the $\sim 1$ eV$^2$ scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrin…
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There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the $\sim 1$ eV$^2$ scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrinos and which may be related to the LSND signal. No excess of electron-like events ($-0.5 \pm 7.8 \pm 8.7$), however, is observed so far at low energies in antineutrino mode. Furthermore, global 3+1 and 3+2 sterile neutrino fits to the world neutrino and antineutrino data suggest a difference between neutrinos and antineutrinos with significant ($\sin^22θ_{μμ} \sim 35%$) $\bar ν_μ$ disappearance. In order to test whether the low-energy excess is due to neutrino oscillations and whether there is a difference between $ν_μ$ and $\bar ν_μ$ disappearance, we propose building a second MiniBooNE detector at (or moving the existing MiniBooNE detector to) a distance of $\sim 200$ m from the Booster Neutrino Beam (BNB) production target. With identical detectors at different distances, most of the systematic errors will cancel when taking a ratio of events in the two detectors, as the neutrino flux varies as $1/r^2$ to a calculable approximation. This will allow sensitive tests of oscillations for both $ν_e$ and $\bar ν_e$ appearance and $ν_μ$ and $\bar ν_μ$ disappearance. Furthermore, a comparison between oscillations in neutrino mode and antineutrino mode will allow a sensitive search for CP and CPT violation in the lepton sector at short baseline ($Δm^2 > 0.1$ eV$^2$).
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Submitted 14 October, 2009;
originally announced October 2009.
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Measurement of the ν_μcharged current π^+ to quasi-elastic cross section ratio on mineral oil in a 0.8 GeV neutrino beam
Authors:
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Buge,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
R. Imlay,
R. A. Johnson,
G. Karagiorgi,
P. Kasper
, et al. (56 additional authors not shown)
Abstract:
Using high statistics samples of charged current $ν_μ$ interactions, MiniBooNE reports a measurement of the single charged pion production to quasi-elastic cross section ratio on mineral oil (CH$_2$), 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 $< E_ν<$ 2.4 GeV with 11% precision…
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Using high statistics samples of charged current $ν_μ$ interactions, MiniBooNE reports a measurement of the single charged pion production to quasi-elastic cross section ratio on mineral oil (CH$_2$), 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 $< E_ν<$ 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.
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Submitted 20 April, 2009;
originally announced April 2009.
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First Measurement of $ν_μ$ and $ν_e$ Events in an Off-Axis Horn-Focused Neutrino Beam
Authors:
P. Adamson,
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
M. Bishai,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
B. C. Choudhary,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
H. R. Gallagher,
F. G. Garcia,
G. T. Garvey,
C. Green,
J. A. Green,
D. Harris,
T. L. Hart
, et al. (71 additional authors not shown)
Abstract:
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 ($6.3^{\circ}$) with respect to the NuMI beam axis. Samples of charged current quasi-elastic $ν_μ$ and $ν_e$ interactions are analyzed and found to be in agreement with expectatio…
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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 ($6.3^{\circ}$) with respect to the NuMI beam axis. Samples of charged current quasi-elastic $ν_μ$ and $ν_e$ 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.
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Submitted 21 July, 2009; v1 submitted 15 September, 2008;
originally announced September 2008.
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Recent Results from MiniBooNE
Authors:
Byron P. Roe
Abstract:
Recent results from MiniBooNE are described. These include neutrino oscillation results, low energy anomaly, and neutrino/antineutrino cross sections.
Recent results from MiniBooNE are described. These include neutrino oscillation results, low energy anomaly, and neutrino/antineutrino cross sections.
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Submitted 19 May, 2008;
originally announced May 2008.
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First Observation of Coherent $π^0$ Production in Neutrino Nucleus Interactions with $E_ν<$ 2 GeV
Authors:
The MiniBooNE Collaboration,
A. A. Aguilar-Arevalo,
C. E. Anderson,
A. O. Bazarko,
S. J. Brice,
B. C. Brown,
L. Bugel,
J. Cao,
L. Coney,
J. M. Conrad,
D. C. Cox,
A. Curioni,
Z. Djurcic,
D. A. Finley,
B. T. Fleming,
R. Ford,
F. G. Garcia,
G. T. Garvey,
C. Green,
J. A. Green,
T. L. Hart,
E. Hawker,
R. Imlay,
R. A. Johnson,
G. Karagiori
, et al. (56 additional authors not shown)
Abstract:
The MiniBooNE experiment at Fermilab has amassed the largest sample to date of $π^0$s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of $π^0$s produced in mineral oil (CH$_2$) and the first observation of coherent $π^0$ production below 2 GeV. In the forward direction, the yield of events observed above…
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The MiniBooNE experiment at Fermilab has amassed the largest sample to date of $π^0$s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of $π^0$s produced in mineral oil (CH$_2$) and the first observation of coherent $π^0$ 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 $\pm$1.1 (stat) $\pm$2.5 (sys))% of all exclusive NC $π^0$ production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for $ν_μ \to ν_e$ oscillations.
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Submitted 24 March, 2008;
originally announced March 2008.
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Studies of Stability and Robustness for Artificial Neural Networks and Boosted Decision Trees
Authors:
Hai-Jun Yang,
Byron P. Roe,
Ji Zhu
Abstract:
In this paper, we compare the performance, stability and robustness of Artificial Neural Networks (ANN) and Boosted Decision Trees (BDT) using MiniBooNE Monte Carlo samples. These methods attempt to classify events given a number of identification variables. The BDT algorithm has been discussed by us in previous publications. Testing is done in this paper by smearing and shifting the input varia…
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In this paper, we compare the performance, stability and robustness of Artificial Neural Networks (ANN) and Boosted Decision Trees (BDT) using MiniBooNE Monte Carlo samples. These methods attempt to classify events given a number of identification variables. The BDT algorithm has been discussed by us in previous publications. Testing is done in this paper by smearing and shifting the input variables of testing samples. Based on these studies, BDT has better particle identification performance than ANN. The degradation of the classifications obtained by shifting or smearing variables of testing results is smaller for BDT than for ANN.
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Submitted 8 February, 2007; v1 submitted 31 October, 2006;
originally announced October 2006.
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Studies of Boosted Decision Trees for MiniBooNE Particle Identification
Authors:
Hai-Jun Yang,
Byron P. Roe,
Ji Zhu
Abstract:
Boosted decision trees are applied to particle identification in the MiniBooNE experiment operated at Fermi National Accelerator Laboratory (Fermilab) for neutrino oscillations. Numerous attempts are made to tune the boosted decision trees, to compare performance of various boosting algorithms, and to select input variables for optimal performance.
Boosted decision trees are applied to particle identification in the MiniBooNE experiment operated at Fermi National Accelerator Laboratory (Fermilab) for neutrino oscillations. Numerous attempts are made to tune the boosted decision trees, to compare performance of various boosting algorithms, and to select input variables for optimal performance.
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Submitted 7 August, 2005;
originally announced August 2005.
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Boosted Decision Trees as an Alternative to Artificial Neural Networks for Particle Identification
Authors:
Byron P. Roe,
Hai-Jun Yang,
Ji Zhu,
Yong Liu,
Ion Stancu,
Gordon McGregor
Abstract:
The efficacy of particle identification is compared using artificial neutral networks and boosted decision trees. The comparison is performed in the context of the MiniBooNE, an experiment at Fermilab searching for neutrino oscillations. Based on studies of Monte Carlo samples of simulated data, particle identification with boosting algorithms has better performance than that with artificial neu…
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The efficacy of particle identification is compared using artificial neutral networks and boosted decision trees. The comparison is performed in the context of the MiniBooNE, an experiment at Fermilab searching for neutrino oscillations. Based on studies of Monte Carlo samples of simulated data, particle identification with boosting algorithms has better performance than that with artificial neural networks for the MiniBooNE experiment. Although the tests in this paper were for one experiment, it is expected that boosting algorithms will find wide application in physics.
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Submitted 19 November, 2004; v1 submitted 30 August, 2004;
originally announced August 2004.
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Event Selection Using an Extended Fisher Discriminant Method
Authors:
Byron P. Roe
Abstract:
This note discusses the problem of choosing between hypotheses in a situation with many, correlated non-normal variables. A new method is introduced to shrink the many variables into a smaller subset of variables with zero mean, unit variance, and zero correlation coefficient between variables. These new variables are well suited to use in a neural net.
This note discusses the problem of choosing between hypotheses in a situation with many, correlated non-normal variables. A new method is introduced to shrink the many variables into a smaller subset of variables with zero mean, unit variance, and zero correlation coefficient between variables. These new variables are well suited to use in a neural net.
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Submitted 29 October, 2003;
originally announced October 2003.
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Setting Confidence Belts
Authors:
Byron P. Roe,
Michael B. Woodroofe
Abstract:
We propose using a Bayes procedure with uniform improper prior to determine credible belts for the mean of a Poisson distribution in the presence of background and for the continuous problem of measuring a non-negative quantity $θ$ with a normally distributed measurement error. Within the Bayesian framework, these belts are optimal. The credible limits are then examined from a frequentist point…
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We propose using a Bayes procedure with uniform improper prior to determine credible belts for the mean of a Poisson distribution in the presence of background and for the continuous problem of measuring a non-negative quantity $θ$ with a normally distributed measurement error. Within the Bayesian framework, these belts are optimal. The credible limits are then examined from a frequentist point of view and found to have good frequentist and conditional frequentist properties.
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Submitted 13 October, 2000; v1 submitted 24 July, 2000;
originally announced July 2000.
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Improved Probability Method for Estimating Signal in the Presence of Background
Authors:
Byron P. Roe,
Michael B. Woodroofe
Abstract:
A suggestion is made for improving the Feldman Cousins method of estimating signal counts in the presence of background. The method concentrates on finding essential information about the signal and ignoring extraneous information about background. An appropriate method is found which uses the condition that the number of background events obtained does not exceed the total number of events obta…
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A suggestion is made for improving the Feldman Cousins method of estimating signal counts in the presence of background. The method concentrates on finding essential information about the signal and ignoring extraneous information about background. An appropriate method is found which uses the condition that the number of background events obtained does not exceed the total number of events obtained. Several alternative approaches are explored.
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Submitted 11 August, 1999; v1 submitted 18 December, 1998;
originally announced December 1998.
