0000000001017866
AUTHOR
R. A. Johnson
T2K neutrino flux prediction
The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an off-axismuon neutrino beam with a peak energy of about 0.6 GeV that originates at the Japan Proton Accelerator Research Complex accelerator facility. Interactions of the neutrinos are observed at near detectors placed at 280 m from the production target and at the far detector-Super-Kamiokande-located 295 km away. The flux prediction is an essential part of the successful prediction of neutrino interaction rates at the T2K detectors and is an important input to T2K neutrino oscillation and cross section measurements. A FLUKA and GEANT3-based simulation models the physical processes involved in the neutrino producti…
Optimization of the JUNO liquid scintillator composition using a Daya Bay antineutrino detector
To maximize the light yield of the liquid scintillator (LS) for the Jiangmen Underground Neutrino Observatory (JUNO), a 20 t LS sample was produced in a pilot plant at Daya Bay. The optical properties of the new LS in various compositions were studied by replacing the gadolinium-loaded LS in one antineutrino detector. The concentrations of the fluor, PPO, and the wavelength shifter, bis-MSB, were increased in 12 steps from 0.5 g/L and <0.01 mg/L to 4 g/L and 13 mg/L, respectively. The numbers of total detected photoelectrons suggest that, with the optically purified solvent, the bis-MSB concentration does not need to be more than 4 mg/L. To bridge the one order of magnitude in the detect…
Measurement of neutrino-induced charged-current charged pion production cross sections on mineral oil atEν∼1 GeV
Using a high-statistics, high-purity sample of {nu}{sub {mu}-}induced charged current, charged pion events in mineral oil (CH{sub 2}), MiniBooNE reports a collection of interaction cross sections for this process. This includes measurements of the CC{pi}{sup +} 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…
Measurements of the T2K neutrino beam properties using the INGRID on-axis near detector
Precise measurement of neutrino beam direction and intensity was achieved based on a new concept with modularized neutrino detectors. INGRID (Interactive Neutrino GRID) is an on-axis near detector for the T2K long baseline neutrino oscillation experiment. INGRID consists of 16 identical modules arranged in horizontal and vertical arrays around the beam center. The module has a sandwich structure of iron target plates and scintillator trackers. INGRID directly monitors the muon neutrino beam profile center and intensity using the number of observed neutrino events in each module. The neutrino beam direction is measured with accuracy better than 0.4 mrad from the measured profile center. The …
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 $0.76 \pm 0.11$, while the CCQE an…
Measurement ofνμandν¯μinduced neutral current singleπ0production cross sections on mineral oil atEν∼O(1 GeV)
MiniBooNE reports the first absolute cross sections for neutral current single {pi}{sup 0} production on CH{sub 2} induced by neutrino and antineutrino interactions measured from the largest sets of NC {pi}{sup 0} events collected to date. The principal result consists of differential cross sections measured as functions of {pi}{sup 0} momentum and {pi}{sup 0} angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76 {+-} 0.05{sub stat} {+-} 0.40{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of = 808 MeV and (1.48 {+-} 0.05{sub stat} {+-} 0.14{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of = 664 MeV for {nu}{sub {mu}} and {bar {nu}…
Measurement ofνμ-induced charged-current neutral pion production cross sections on mineral oil atEν∈0.5–2.0 GeV
The authors would like to acknowledge the support of Fermilab, the Department of Energy, and the National Science Foundation in the construction, operation, and data analysis of the Mini Booster Neutrino Experiment.
Dual baseline search for muon neutrino disappearance at0.5 eV2<Δm2<40 eV2
The SciBooNE and MiniBooNE collaborations report the results of a νμ disappearance search in the Δ'm2 region of 0.5-40 eV2. 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 νμ disappearance in the 0.5-40 eV2 Δm2 region, with an improvement over previous experimental constraints between 10 and 30 eV2
Measurement of the inclusive $\nu_{\mu}$ charged current cross section on iron and hydrocarbon in the T2K on-axis neutrino beam
We report a measurement of the $\nu_\mu$ inclusive charged current cross sections on iron and hydrocarbon in the T2K on-axis neutrino beam. The measured inclusive charged current cross sections on iron and hydrocarbon averaged over the T2K on-axis flux with a mean neutrino energy of 1.51 GeV are $(1.444\pm0.002(stat.)_{-0.157}^{+0.189}(syst.))\times 10^{-38}\mathrm{cm}^2/\mathrm{nucleon}$, and $(1.379\pm0.009(stat.)_{-0.147}^{+0.178}(syst.))\times 10^{-38}\mathrm{cm}^2/\mathrm{nucleon}$, respectively, and their cross section ratio is $1.047\pm0.007(stat.)\pm0.035(syst.)$. These results agree well with the predictions of the neutrino interaction model, and thus we checked the correct treatme…
Measurement of the Ratio of theνμCharged-Current Single-Pion Production to Quasielastic Scattering with a 0.8 GeV Neutrino Beam on Mineral Oil
Charged current single pion production (CC{pi}{sup +}) and charged current quasi-elastic scattering (CCQE) are the most abundant interaction types for neutrinos at energies around 1 GeV, a region of great interest to oscillation experiments. The cross-sections for these processes, however, are not well understood in this energy range. This dissertation presents a measurement of the ratio of CC{pi}{sup +} to CCQE cross-sections for muon neutrinos on mineral oil (CH{sub 2}) in the MiniBooNE experiment. The measurement is presented here both with and without corrections for hadronic re-interactions in the target nucleus and is given as a function of neutrino energy in the range 0.4 GeV < E{sub…
Observation of Electron Neutrino Appearance in a Muon Neutrino Beam
The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3$\sigma$ when compared to 4.92 $\pm$ 0.55 expected background events. In the PMNS mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles $\theta_{12}$, $\theta_{23}$, $\theta_{13}$, a mass difference $\Delta m^2_{32}$ and a CP violating phase $\delta_{\mathrm{CP}}$. In this neutrino oscillation scenario, assuming $…
Search for Core-Collapse Supernovae using the MiniBooNE Neutrino Detector
We present a search for core-collapse supernovae in the Milky Way galaxy, using the MiniBooNE neutrino detector. No evidence is found for core-collapse supernovae occurring in our Galaxy in the period from December 14, 2004 to July 31, 2008, corresponding to 98% live time for collection. We set a limit on the core-collapse supernova rate out to a distance of 13.4 kpc to be less than 0.69 supernovae per year at 90% C. L.
Test of Lorentz and CPT violation with short baseline neutrino oscillation excesses
The sidereal time dependence of MiniBooNE ν[subscript e] and ν[over-bar][subscript e] appearance data is analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov–Smirnov (K–S) test shows both the ν[subscript e] and ν[over-bar][subscript e] 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 ν[subscript e] appearance data prefer a sidereal time-independent solution, and the ν[over-bar][subscript e] appearance data slightly prefer a sidereal…
Search for Electron Antineutrino Appearance at theΔm2∼1 eV2Scale
The MiniBooNE Collaboration reports initial results from a search for nu{sub m}u->nu{sub e} oscillations. A signal-blind analysis was performed using a data sample corresponding to 3.39x10{sup 20} protons on target. The data are consistent with background prediction across the full range of neutrino energy reconstructed assuming quasielastic scattering, 200<E{sub n}u{sup QE}<3000 MeV: 144 electronlike events have been observed in this energy range, compared to an expectation of 139.2+-17.6 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 …
Volume I. Introduction to DUNE
Journal of Instrumentation 15(08), T08008 (1-228) (2020). doi:10.1088/1748-0221/15/08/T08008
Measurement of the neutrino neutral-current elastic differential cross section on mineral oil atEν∼1 GeV
We report a measurement of the flux-averaged neutral-current elastic differential cross section for neutrinos scattering on mineral oil (CH{sub 2}) as a function of four-momentum transferred squared, Q{sup 2}. It is obtained by measuring the kinematics of recoiling nucleons with kinetic energy greater than 50 MeV which are readily detected in MiniBooNE. This differential cross-section distribution is fit with fixed nucleon form factors apart from an axial mass M{sub A} that provides a best fit for M{sub A}=1.39{+-}0.11 GeV. Using the data from the charged-current neutrino interaction sample, a ratio of neutral-current to charged-current quasielastic cross sections as a function of Q{sup 2} …
Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam
The T2K experiment observes indications of $\nu_\mu\rightarrow \nu_e$ appearance in data accumulated with $1.43\times10^{20}$ protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with $|\Delta m_{23}^2|=2.4\times10^{-3}$ eV$^2$, $\sin^2 2\theta_{23}=1$ and $\sin^2 2\theta_{13}=0$, the expected number of such events is 1.5$\pm$0.3(syst.). Under this hypothesis, the probability to observe six or more candidate events is 7$\times10^{-3}$, equivalent to 2.5$\sigma$ significance. At 90% C.L., the data are consistent with 0.03(0.04)$<\sin^2 2\theta_{13}<$ 0.28(0.34) for $\delta_{\rm CP}=0$ and a normal (inverted) hierarchy.
First Muon-Neutrino Disappearance Study with an Off-Axis Beam
We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 × 10(20) protons on target, we observe 31 fully-contained single μ-like ring events in Super-Kamiokande, compared with an expectation of 104 ± 14(syst) events without neutrino oscillations. The best-fit point for two-flavor νμ → ντ oscillations is sin 2(2θ(23)) = 0.98 and |Δm(2)(32)| = 2.65 × 10(−3) eV2. The boundary of the 90% confidence region includes the points (sin2 (2θ(23)), |Δm(2)(32)|) = (1.0, 3.1 × 10(−3) eV2), (0.84, …
Precise measurement of the neutrino mixing parameter θ23 from muon neutrino disappearance in an off-axis beam
New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter theta_{23}. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57 x 10^{20} protons on target, T2K has fit the energy-dependent nu_mu oscillation probability to determine oscillation parameters. Marginalizing over the values of other oscillation parameters yields sin^2 (theta_{23}) = 0.514 +0.055/-0.056 (0.511 +- 0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Delta m^2_{32} = (2.51 +- 0.10) x 10^{-3} eV^2/c^4 (inverted hierarchy: Delta m^2_{13} = (2.48 +- 0.10) …
Event Excess in the MiniBooNE Search forν¯μ→ν¯eOscillations
The MiniBooNE experiment at Fermilab reports results from a search for {nu}{sub {mu}{yields}{nu}e} oscillations, using a data sample corresponding to 5.66x10{sup 20} protons on target. An excess of 20.9{+-}14.0 events is observed in the energy range 475<E{sub {nu}}{sup QE}<1250 MeV, which, when constrained by the observed {nu}{sub {mu}} events, has a probability for consistency with the background-only hypothesis of 0.5%. On the other hand, fitting for {nu}{sub {mu}{yields}{nu}e} oscillations, the best-fit point has a {chi}{sup 2} probability of 8.7%. The data are consistent with {nu}{sub {mu}{yields}{nu}e} oscillations in the 0.1 to 1.0 eV{sup 2} {Delta}m{sup 2} range and with the evidence…
Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation gamma rays
We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section. It is obtained by observing nuclear deexcitation $\gamma$-rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to $3.01 \times 10^{20}$ protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the $4-30$ MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background …
Search for Muon Neutrino and Antineutrino Disappearance in MiniBooNE
The MiniBooNE Collaboration reports a search for nu(mu) and nu(mu) disappearance in the Delta m(2) region of 0.5-40 eV(2). These measurements are important for constraining models with extra types of neutrinos, extra dimensions, and CPT violation. Fits to the shape of the nu(mu) and nu(mu) energy spectra reveal no evidence for disappearance at the 90% confidence level (C.L.) in either mode. The test of nu(mu) disappearance probes a region below Delta m(2)=40 eV(2) never explored before.
Neutrino flux prediction at MiniBooNE
The booster neutrino experiment (MiniBooNE) searches for nu(mu)->nu(e) oscillations using the O(1 GeV) neutrino beam produced by the booster synchrotron at the Fermi National Accelerator Laboratory). The booster delivers protons with 8 GeV kinetic energy (8.89 GeV/c momentum) to a beryllium target, producing neutrinos from the decay of secondary particles in the beam line. We describe the Monte Carlo simulation methods used to estimate the flux of neutrinos from the beam line incident on the MiniBooNE detector for both polarities of the focusing horn. The simulation uses the Geant4 framework for propagating particles, accounting for electromagnetic processes and hadronic interactions in the…
Unifying Concepts for Ion-Induced Leakage Current Degradation in Silicon Carbide Schottky Power Diodes
The onset of ion-induced reverse leakage current in SiC Schottky diodes is shown to depend on material properties, ion LET, and bias during irradiation, but not the voltage rating of the parts. This is demonstrated experimentally for devices from multiple manufacturers with voltage ratings from 600 V to 1700 V. Using a device with a higher breakdown voltage than required in the application does not provide increased robustness related to leakage current degradation, compared to using a device with a lower voltage rating. peerReviewed
Unexplained Excess of Electronlike Events from a 1-GeV Neutrino Beam
The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46 x 10(20) protons on target, 544 electronlike events are observed in this energy range, compared to an expectation of 415.2 +/- 43.4 events, corresponding to an excess of 128.8 +/- 20.4 +/- 38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu(e) and (nu) over bar (e) charged-current scattering or nu(mu) neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are obse…
Measurement of the Inclusive NuMu Charged Current Cross Section on Carbon in the Near Detector of the T2K Experiment
T2K has performed the first measurement of nu(mu) inclusive charged current interactions on carbon at neutrino energies of similar to 1 GeV where the measurement is reported as a flux-averaged double differential cross section in muon momentum and angle. The flux is predicted by the beam Monte Carlo and external data, including the results from the NA61/SHINE experiment. The data used for this measurement were taken in 2010 and 2011, with a total of 10.8 x 10(19) protons-on-target. The analysis is performed on 4485 inclusive charged current interaction candidates selected in the most upstream fine-grained scintillator detector of the near detector. The flux-averaged total cross section is (…
Volume III. DUNE far detector technical coordination
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay-these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the st…
Estimating Terrestrial Neutron-Induced SEB Cross-Sections and FIT Rates for High-Voltage SiC Power MOSFETs
Cross sections and failure in time rates for neutron-induced single-event burnout (SEB) are estimated for SiC power MOSFETs using a method based on combining results from heavy ion SEB experimental data, 3-D TCAD prediction of sensitive volumes, and Monte Carlo radiation transport simulations of secondary particle production. The results agree well with experimental data and are useful in understanding the mechanisms for neutron-induced SEB data. peerReviewed
Measurement of the Inclusive Electron Neutrino Charged Current Cross Section on Carbon with the T2K Near Detector
The T2K off-axis near detector, ND280, is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies ~1 GeV as a function of electron momentum, electron scattering angle and four-momentum transfer of the interaction. The total flux-averaged $\nu_e$ charged current cross-section on carbon is measured to be $1.11\pm0.09~(stat)\pm0.18~(syst)\times10^{-38} cm^2/nucleon$. The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is $1.23\times10^{-38} cm^2/nucleon$ and the GENIE prediction is $1.08\times10^{-38} cm^2/nucleon$…
The T2K Experiment
The T2K experiment is a long-baseline neutrino oscillation experiment. Its main goal is to measure the last unknown lepton sector mixing angle {\theta}_{13} by observing {\nu}_e appearance in a {\nu}_{\mu} beam. It also aims to make a precision measurement of the known oscillation parameters, {\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via {\nu}_{\mu} disappearance studies. Other goals of the experiment include various neutrino cross section measurements and sterile neutrino searches. The experiment uses an intense proton beam generated by the J-PARC accelerator in Tokai, Japan, and is composed of a neutrino beamline, a near detector complex (ND280), and a far detector (Super-Kamiokande)…
Evidence of Electron Neutrino Appearance in a Muon Neutrino Beam
The T2K Collaboration reports evidence for electron neutrino appearance at the atmospheric mass splitting, vertical bar Delta m(32)(2)vertical bar approximate to 2.4 X 10(-3) eV(2). An excess of electron neutrino interactions over background is observed from a muon neutrino beam with a peak energy of 0.6 GeV at the Super-Kamiokande (SK) detector 295 km from the beam's origin. Signal and background predictions are constrained by data from near detectors located 280 m from the neutrino production target. We observe 11 electron neutrino candidate events at the SK detector when a background of 3.3 +/- 0.4(syst) events is expected. The background-only hypothesis is rejected with a p value of 0.0…