26 research outputs found
Measurement of νΟ charged-current single Ď0 production on hydrocarbon in the few-GeV region using MINERvA
The semiexclusive channel νΟ+CHâÎź-Ď0+nucleon(s) is analyzed using MINERvA exposed to the low-energy NuMI νΟ beam with spectral peak at Eνâ3 GeV. Differential cross sections for muon momentum and production angle, Ď0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section Ď(Eν) is obtained over the range 1.5 GeVâ¤Eν<20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current Ď+(Ď0) production by νΟ(νΟ) neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflect shortfalls in modeling of interactions on carbon. For Ď0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as Ď0 mesons, the pĎ0 invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the pĎ0 system are measured in the region of Î(1232)+ production, W<1.4 GeV
Neutrino flux predictions for the NuMI beam
Knowledge of the neutrino flux produced by the Neutrinos at the Main Injector (NuMI) beamline is essential to the neutrino oscillation and neutrino interaction measurements of the MINERvA, MINOS+, NOvA and MicroBooNE experiments at Fermi National Accelerator Laboratory. We have produced a flux prediction which uses all available and relevant hadron production data, incorporating measurements of particle production off of thin targets as well as measurements of particle yields from a spare NuMI target exposed to a 120 GeV proton beam. The result is the most precise flux prediction achieved for a neutrino beam in the one to tens of GeV energy region. We have also compared the prediction to in situ measurements of the neutrino flux and find good agreement
Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA
We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a subsample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, RCC, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of âź5% at low energy. Our results for the antineutrino-nucleus scattering cross section and for RCC are the most precise to date in the energy range Eν<6 GeV
Cross sections for νΟ and ν Ο induced pion production on hydrocarbon in the few-GeV region using MINERvA CROSS SECTIONS for νΟ and ν Ο ... C. L. MCGIVERN et al
Separate samples of charged-current pion production events representing two semi-inclusive channels νΟ-CC(Ď+) and νΟ-CC(Ď0) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon Ο¹-track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer Q2 are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the Î(1232) and higher-mass baryon resonances in CC pion production and to show the importance of pion final-state interactions. For the νΟ-CC(Ď+) [νΟ-CC(Ď0)] sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to- 2Ď. However the generators are able to reproduce the shapes of the differential cross sections for all kinematic variables of either data set
Evidence for Neutral-Current Diffractive Ď0 Production from Hydrogen in Neutrino Interactions on Hydrocarbon
The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current Ď0 production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26Âą0.02(stat.)Âą0.08(sys.)Ă10-39 cm2. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive Ď0 production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for νΟ to νe oscillations
Measurement of partonic nuclear effects in deep-inelastic neutrino scattering using MINERvA
The MINERvA Collaboration reports a novel study of neutrino-nucleus charged-current deep inelastic scattering (DIS) using the same neutrino beam incident on targets of polystyrene, graphite, iron, and lead. Results are presented as ratios of C, Fe, and Pb to CH. The ratios of total DIS cross sections as a function of neutrino energy and flux-integrated differential cross sections as a function of the Bjorken scaling variable x are presented in the neutrino-energy range of 5-50 GeV. Based on the predictions of charged-lepton scattering ratios, good agreement is found between the data and prediction at medium x and low neutrino energy. However, the ratios appear to be below predictions in the vicinity of the nuclear shadowing region, x<0.1. This apparent deficit, reflected in the DIS cross-section ratio at high Eν, is consistent with previous MINERvA observations [B. Tice (MINERvA Collaboration), Phys. Rev. Lett. 112, 231801 (2014).] and with the predicted onset of nuclear shadowing with the axial-vector current in neutrino scattering
Measurement of Neutral-Current K+ Production by Neutrinos using MINERvA
Neutral-current production of K+ by atmospheric neutrinos is a background in searches for the proton decay pâK+ν. Reactions such as νpâνK+Î are indistinguishable from proton decays when the decay products of the Î are below detection threshold. Events with K+ are identified in MINERvA by reconstructing the timing signature of a K+ decay at rest. A sample of 201 neutrino-induced neutral-current K+ events is used to measure differential cross sections with respect to the K+ kinetic energy, and the non-K+ hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the neut event generator. Good agreement is observed with the cross section prediction of the genie generator. A search for photons from Ď0 decay, which would veto a neutral-current K+ event in a proton decay search, is performed, and a 2Ď deficit of detached photons is observed relative to the genie prediction
Measurement of K+ production in charged-current νΟ interactions
Production of K+ mesons in charged-current νΟ interactions on plastic scintillator (CH) is measured using MINERvA exposed to the low-energy NuMI beam at Fermilab. Timing information is used to isolate a sample of 885 charged-current events containing a stopping K+ which decays at rest. The differential cross section in K+ kinetic energy, dĎ/dTK, is observed to be relatively flat between 0 and 500 MeV. Its shape is in good agreement with the prediction by the genie neutrino event generator when final-state interactions are included, however the data rate is lower than the prediction by 15%
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Neutrino factory
The properties of the neutrino provide a unique window on physics beyond that described by the standard model. The study of subleading effects in neutrino oscillations, and the race to discover CP-invariance violation in the lepton sector, has begun with the recent discovery that θ13>0. The measured value of θ13 is large, emphasizing the need for a facility at which the systematic uncertainties can be reduced to the percent level. The neutrino factory, in which intense neutrino beams are produced from the decay of muons, has been shown to outperform all realistic alternatives and to be capable of making measurements of the requisite precision. Its unique discovery potential arises from the fact that only at the neutrino factory is it practical to produce high-energy electron (anti)neutrino beams of the required intensity. This paper presents the conceptual design of the neutrino factory accelerator facility developed by the European Commission Framework Programme 7 EUROν Design Study consortium. EUROν coordinated the European contributions to the International Design Study for the Neutrino Factory (the IDS-NF) collaboration. The EUROν baseline accelerator facility will provide 10^21 muon decays per year from 12.6 GeV stored muon beams serving a single neutrino detector situated at a source-detector distance of between 1â500 km and 2â500 km. A suite of near detectors will allow definitive neutrino-scattering experiments to be performed