214 research outputs found

    Measurement of νˉμ\bar{\nu}_{\mu} and νμ\nu_{\mu} charged current inclusive cross sections and their ratio with the T2K off-axis near detector

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    We report a measurement of cross section σ(νμ+nucleusμ+X)\sigma(\nu_{\mu}+{\rm nucleus}\rightarrow\mu^{-}+X) and the first measurements of the cross section σ(νˉμ+nucleusμ++X)\sigma(\bar{\nu}_{\mu}+{\rm nucleus}\rightarrow\mu^{+}+X) and their ratio R(σ(νˉ)σ(ν))R(\frac{\sigma(\bar \nu)}{\sigma(\nu)}) at (anti-)neutrino energies below 1.5 GeV. We determine the single momentum bin cross section measurements, averaged over the T2K νˉ/ν\bar{\nu}/\nu-flux, for the detector target material (mainly Carbon, Oxygen, Hydrogen and Copper) with phase space restricted laboratory frame kinematics of θμ\theta_{\mu}500 MeV/c. The results are σ(νˉ)=(0.900±0.029(stat.)±0.088(syst.))×1039\sigma(\bar{\nu})=\left( 0.900\pm0.029{\rm (stat.)}\pm0.088{\rm (syst.)}\right)\times10^{-39} and $\sigma(\nu)=\left( 2.41\ \pm0.022{\rm{(stat.)}}\pm0.231{\rm (syst.)}\ \right)\times10^{-39}inunitsofcm in units of cm^{2}/nucleonand/nucleon and R\left(\frac{\sigma(\bar{\nu})}{\sigma(\nu)}\right)= 0.373\pm0.012{\rm (stat.)}\pm0.015{\rm (syst.)}$.Comment: 18 pages, 8 figure

    Measurement of the Double-Differential Muon-neutrino Charged-Current Inclusive Cross Section in the NOvA Near Detector

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    We report cross-section measurements of the final-state muon kinematics for \numu charged-current interactions in the NOvA near detector using an accumulated 8.09×1020\times10^{20} protons-on-target (POT) in the NuMI beam. We present the results as a double-differential cross section in the observed outgoing muon energy and angle, as well as single-differential cross sections in the derived neutrino energy, EνE_\nu, and square of the four-momentum transfer, Q2Q^2. We compare the results to inclusive cross-section predictions from various neutrino event generators via χ2\chi^2 calculations using a covariance matrix that accounts for bin-to-bin correlations of systematic uncertainties. These comparisons show a clear discrepancy between the data and each of the tested predictions at forward muon angle and low Q2Q^2, indicating a missing suppression of the cross section in current neutrino-nucleus scattering models

    An Improved Measurement of Neutrino Oscillation Parameters by the NOvA Experiment

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    We present new νμνe\nu_\mu\rightarrow\nu_e, νμνμ\nu_\mu\rightarrow\nu_\mu, νμνe\overline{\nu}_\mu\rightarrow\overline{\nu}_e, and νμνμ\overline{\nu}_\mu\rightarrow\overline{\nu}_\mu oscillation measurements by the NOvA experiment, with a 50% increase in neutrino-mode beam exposure over the previously reported results. The additional data, combined with previously published neutrino and antineutrino data, are all analyzed using improved techniques and simulations. A joint fit to the νe\nu_e, νμ\nu_\mu, νe\overline{\nu}_e, and νμ\overline{\nu}_\mu candidate samples within the 3-flavor neutrino oscillation framework continues to yield a best-fit point in the normal mass ordering and the upper octant of the θ23\theta_{23} mixing angle, with Δm322=(2.41±0.07)×103\Delta m^{2}_{32} = (2.41\pm0.07)\times 10^{-3} eV2^2 and sin2θ23=0.570.04+0.03\sin^2\theta_{23} = 0.57^{+0.03}_{-0.04}. The data disfavor combinations of oscillation parameters that give rise to a large asymmetry in the rates of νe\nu_e and νe\overline{\nu}_e appearance. This includes values of the CP-violating phase in the vicinity of δCP=π/2\delta_\text{CP} = \pi/2 which are excluded by >3σ>3\sigma for the inverted mass ordering, and values around δCP=3π/2\delta_\text{CP} = 3\pi/2 in the normal ordering which are disfavored at 2σ\sigma confidence.Comment: 11 pages, 6 figures. Supplementary material attached (7 figures

    Seasonal Variation of Multiple-Muon Cosmic Ray Air Showers Observed in the NOvA Detector on the Surface

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    We report the rate of cosmic ray air showers with multiplicities exceeding 15 muon tracks recorded in the NOvA Far Detector between May 2016 and May 2018. The detector is located on the surface under an overburden of 3.6 meters water equivalent. We observe a seasonal dependence in the rate of multiple-muon showers, which varies in magnitude with multiplicity and zenith angle. During this period, the effective atmospheric temperature and surface pressure ranged between 210 K to 230 K and 940mbar to 990mbar, respectively; the shower rates are anti-correlated with the variation in the effective temperature. The variations are about 30% larger for the highest multiplicities than the lowest multiplicities and 20% larger for showers near the horizon than vertical showers

    TITUS: the Tokai Intermediate Tank for the Unoscillated Spectrum

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    68 pages.38 figures68 pages.38 figures68 pages.38 figures70 pages, 41 figuresThe TITUS, Tokai Intermediate Tank for Unoscillated Spectrum, detector, is a proposed Gd-doped Water Cherenkov tank with a magnetised muon range detector downstream. It is located at J-PARC at about 2 km from the neutrino target and it is proposed as a potential near detector for the Hyper-Kamiokande experiment. Assuming a beam power of 1.3 MW and 27.05 x 10^{21} protons-on-target the sensitivity to CP and mixing parameters achieved by Hyper-Kamiokande with TITUS as a near detector is presented. Also, the potential of the detector for cross sections and Standard Model parameter determination, supernova neutrino and dark matter are shown

    Extended search for supernova-like neutrinos in NOvA coincident with LIGO/Virgo detections

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    A search is performed for supernova-like neutrino interactions coincident with 76 gravitational wave events detected by the LIGO/Virgo Collaboration. For 40 of these events, full readout of the time around the gravitational wave is available from the NOvA Far Detector. For these events, we set limits on the fluence of the sum of all neutrino flavors of F<7(4)×1010cm2F < 7(4)\times 10^{10}\mathrm{cm}^{-2} at 90% C.L. assuming energy and time distributions corresponding to the Garching supernova models with masses 9.6(27)M\mathrm{M}_\odot. Under the hypothesis that any given gravitational wave event was caused by a supernova, this corresponds to a distance of r>29(50)r > 29(50)kpc at 90% C.L. Weaker limits are set for other gravitational wave events with partial Far Detector data and/or Near Detector data.Comment: 10 pages, 2 figure
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