E. Laird

The MiniBooNE Collaboration reports first results of a search for nu e appearance in a nu mu beam. With two largely independent analyses, we observe no significant excess of events above the background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two-neutrino appearance-only oscillation model.

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 ($\frac{d^2\sigma}{dT_\mu d\cos\theta_\mu}$) 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 ($\sigma[E_\nu]$) and the single differential cross section ($\frac{d\sigma}{dQ^2}$) 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.

The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46×1020 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 νe and ¯νe charged-current scattering or νμ 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 observed compared to an expectation of 385.9±35.7 events.Received 14 December 2008DOI:https://doi.org/10.1103/PhysRevLett.102.101802©2009 American Physical Society

The Booster Neutrino Experiment (MiniBooNE) searches for ν µ → ν e oscillations using the O(1 GeV) neutrino beam produced by the Booster synchrotron at the Fermi National Accelerator Laboratory (FNAL).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 beamline 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 beamline materials, as well as the decay of particles.The absolute double differential cross sections of pion and kaon production in the simulation have been tuned to match external measurements, as have the hadronic cross sections for nucleons and pions.The statistical precision of the flux predictions is enhanced through reweighting and resampling techniques.Systematic errors in the flux estimation have been determined by varying parameters within their uncertainties, accounting for correlations where appropriate.

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 quasielastic (CCQE) cross sections to predict signal samples. Using a high-statistics sample of νμ 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, MeffA=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, κ=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.Received 8 June 2007DOI:https://doi.org/10.1103/PhysRevLett.100.032301©2008 American Physical Society

We report a measurement of the flux-averaged neutral-current elastic differential cross section for neutrinos scattering on mineral oil (CH2) as a function of four-momentum transferred squared, Q2. 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 MA that provides a best fit for MA=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 Q2 has been measured. Additionally, single protons with kinetic energies above 350 MeV can be distinguished from neutrons and multiple nucleon events. Using this marker, the strange quark contribution to the neutral-current axial vector form factor at Q2=0, Δs, is found to be Δs=0.08±0.26.8 MoreReceived 13 August 2010DOI:https://doi.org/10.1103/PhysRevD.82.092005© 2010 The American Physical Society

The MiniBooNE neutrino detector was designed and built to look for muon-neutrino to electron-neutrino oscillations in the mixing parameter space region where the LSND experiment reported a signal. The MiniBooNE experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBooNE detector.

Using a high-statistics, high-purity sample of ${\ensuremath{\nu}}_{\ensuremath{\mu}}$-induced charged current, charged pion events in mineral oil (${\mathrm{CH}}_{2}$), MiniBooNE reports a collection of interaction cross sections for this process. This includes measurements of the $\mathrm{CC}{\ensuremath{\pi}}^{+}$ 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.

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.

MiniBooNE reports the first absolute cross sections for neutral current single π0 production on CH2 induced by neutrino and antineutrino interactions measured from the largest sets of NC π0 events collected to date. The principal result consists of differential cross sections measured as functions of π0 momentum and π0 angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76±0.05stat±0.76sys)×10−40 cm2/nucleon at a mean energy of ⟨Eν⟩=808 MeV and (1.48±0.05stat±0.23sys)×10−40 cm2/nucleon at a mean energy of ⟨Eν⟩=664 MeV for νμ and ¯νμ induced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1π0 production corrected for the effects of final state interactions to compare to prior results.5 MoreReceived 11 November 2009DOI:https://doi.org/10.1103/PhysRevD.81.013005©2010 American Physical Society

Measurement of #μ-induced

The sidereal time dependence of MiniBooNE νe and ν¯e appearance data is analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov–Smirnov (K–S) test shows both the νe and ν¯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 νe appearance data prefer a sidereal time-independent solution, and the ν¯e appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10−20GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for νμ→νe and ν¯μ→ν¯e oscillations. The fit values and limits of combinations of SME coefficients are provided.

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of π0s produced in neutral current (NC) neutrino–nucleus interactions at low energy. This Letter reports a measurement of the momentum distribution of π0s produced in mineral oil (CH2) and the first observation of coherent π0 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 π0 production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for νμ→νe oscillations.

The Booster Neutrino Experiment (MiniBooNE) searches for νμ→νe oscillations using the ~1GeV neutrino beam produced by the FNAL Booster synchrotron. The array of photomultiplier tubes (PMTs) lining the MiniBooNE detector records Cherenkov and scintillation photons from the charged particles produced in neutrino interactions. We describe a maximum likelihood fitting algorithm used to reconstruct the basic properties (position, direction, energy) of these particles from the charges and times measured by the PMTs. The likelihoods returned from fitting an event to different particle hypotheses are used to categorize it as a signal νe event or as one of the background νμ processes, in particular charged current quasi-elastic scattering and neutral current π0 production. The reconstruction and event selection techniques described here can be applied to current and future neutrino experiments using similar Cherenkov-based detection.

The MiniBooNE Collaboration reports a search for \numu and \numubar disappearance in the \dmsq region of a few \evsq. These measurements are important for constraining models with extra types of neutrinos, extra dimensions an d CPT violation. Fits to the shape of the \numu and \numubar energy spectra reveal no evidence for disappearance at 90% confidence level (CL) in either mode. This is the first test of \numubar disappearance between \dmsq=0.1-10\evsq.

Using high statistics samples of charged-current ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ interactions, the MiniBooNE Collaboration reports a measurement of the single-charged-pion production to quasielastic cross section ratio on mineral oil (${\mathrm{CH}}_{2}$), both with and without corrections for hadron reinteractions in the target nucleus. The result is provided as a function of neutrino energy in the range $0.4\text{ }\text{ }\mathrm{GeV}<{E}_{\ensuremath{\nu}}<2.4\text{ }\text{ }\mathrm{GeV}$ with 11% precision in the region of highest statistics. The results are consistent with previous measurements and the prediction from historical neutrino calculations.

We report the first observation of off-axis neutrino interactions in the MiniBooNE detector from the NuMI beam line at Fermilab. The MiniBooNE detector is located 745 m from the NuMI production target, at 110 mrad angle (6.3°) with respect to the NuMI beam axis. Samples of charged-current quasielastic νμ and νe 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.Received 12 September 2008DOI:https://doi.org/10.1103/PhysRevLett.102.211801©2009 American Physical Society

Abstract The two Zero Degree Calorimeters (ZDCs) of the CMS experiment are located at ± 140 m from the collision point and detect neutral particles in the |η| > 8.3 pseudorapidity region. This paper presents a study on the performance of the ZDC in the 2016 pPb run. The response of the detectors to ultrarelativistic neutrons is studied using in-depth Monte Carlo simulations. A method of signal extraction based on template fits is presented, along with a dedicated calibration procedure. A deconvolution technique for the correction of overlapping collision events is discussed.

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.

This article presents the compatibility of experimental data from neutrino oscillation experiments with a high-Δm2 two-neutrino oscillation hypothesis. Data is provided by the Bugey, Karlsruhe Rutherford Medium Energy Neutrino Experiment 2 (KARMEN2), Los Alamos Liquid Scintillator Neutrino Detector (LSND), and MiniBooNE experiments. The LSND, KARMEN2, and MiniBooNE results are 25.36% compatible within a two-neutrino oscillation hypothesis. However, the point of maximal compatibility is found in a region that is excluded by the Bugey data. A joint analysis of all four experiments, performed in the sin22θ vs Δm2 region common to all data, finds a maximal compatibility of 3.94%. This result does not account for additions to the neutrino oscillation model from sources such as CP violation or sterile neutrinos.3 MoreReceived 13 May 2008DOI:https://doi.org/10.1103/PhysRevD.78.012007©2008 American Physical Society

Many important phenomena in quantum devices are dynamic, meaning that they cannot be studied using time-averaged measurements alone. Experiments that measure such transient effects are collectively known as fast readout. One of the most useful techniques in fast electrical readout is radio-frequency reflectometry, which can measure changes in impedance (both resistive and reactive) even when their duration is extremely short, down to a microsecond or less. Examples of reflectometry experiments, some of which have been realised and others so far only proposed, include projective measurements of qubits and Majorana devices for quantum computing, real-time measurements of mechanical motion and detection of non-equilibrium temperature fluctuations. However, all of these experiments must overcome the central challenge of fast readout: the large mismatch between the typical impedance of quantum devices (set by the resistance quantum) and of transmission lines (set by the impedance of free space). Here, we review the physical principles of radio-frequency reflectometry and its close cousins, measurements of radio-frequency transmission and emission. We explain how to optimise the speed and sensitivity of a radio-frequency measurement, and how to incorporate new tools such as superconducting circuit elements and quantum-limited amplifiers into advanced radio-frequency experiments. Our aim is three-fold: to introduce the readers to the technique, to review the advances to date and to motivate new experiments in fast quantum device dynamics. Our intended audience includes experimentalists in the field of quantum electronics who want to implement radio-frequency experiments or improve them, together with physicists in related fields who want to understand how the most important radio-frequency measurements work.

One of the key input parameters for designing new and rehabilitated pavements is traffic loading which is currently based on the number of equivalent single axle load (ESAL) applications. The Colorado Department of Transportation (CDOT) uses a generalized, averaged, and non-site-specific equivalency factor in calculating the number of ESAL applications. Furthermore, the ESAL applications are developed using a 3-bin vehicle classification scheme instead of the Federal Highway Administration's (FHWA's) recommended 13-bin classification scheme. Lack of site-specific equivalency factors in conjunction with the use of 3-bin vehicle classification has caused under-designing and sometimes over-designing pavements based on inaccurate traffic load data. This study was approved by the CDOT's Research Implementation Committee as a high priority research with the goal of improving the accuracy of the existing and forecasted traffic loads of CDOT's highway network. The overall scope of this project involved examination of those resources directly related to the current statewide ESAL classification system and the generation of this final report discussing the research and analysis conducted and recommendation of procedures required for CDOT to develop and implement a more site-specific ESAL classification system. In this study Nichols Consulting Engineers (NCE) analyzed all available CDOT permanent and portable weigh-in-motion (WIM) data. The analyses indicated that sampling data a few times per year may preclude the installation of new costly permanent WIMs. Adjustment factors developed for reducing the temporal bias from short duration data collection were beneficial for sites. Length data could not be expanded into the FHWA classification scheme but could be used for volume information. NCE developed axle load spectra for each WIM data source and reviewed the historic trends of axle loads from the WIM systems. Equivalency factors were developed to apply to axle load data. Groups were based on functional classification in order to apply monitoring data to segments where no data source was available. NCE evaluated the number of WIM data sources per functional class group and documented the number of WIM sites that will be needed to achieve a desired accuracy. A hierarchy was formulated for new data collection efforts based on functionality of roadway and number of segments that have no monitoring data. WIM data is needed for at least functional class groups rural major collector (07) and urban principal arterial other freeways (12). NCE populated a new and more accurate ESAL design table for use in pavement design and rehabilitation activities. This will result in cost savings to CDOT by increasing the accuracy of the pavement design and rehabilitation process.

Received 4 March 2010DOI:https://doi.org/10.1103/PhysRevLett.104.109902©2010 American Physical Society

The MiniBooNE Collaboration reports a search for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} disappearance in the {Delta}m{sup 2} region of a few eV{sup 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}{sub {mu}} and {bar {nu}}{sub {mu}} energy spectra reveal no evidence for disappearance at 90% confidence level (CL) in either mode. This is the first test of {bar {nu}}{sub {mu}} disappearance between {Delta}m{sup 2} = 0.1-10 eV{sup 2}.

The MiniBooNE Collaboration observes unexplained electron-like events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46 x 10{sup 20} protons on target, 544 electron-like 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}{sub e} and {bar {nu}}{sub e} charged-current scattering or to {nu}{sub {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 observed compared to an expectation of 385.9 {+-} 35.7 events.