231 research outputs found
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First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA.
The NOvA experiment has seen a 4.4σ signal of ν[over ¯]_{e} appearance in a 2 GeV ν[over ¯]_{μ} beam at a distance of 810 km. Using 12.33×10^{20} protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ν[over ¯]_{μ}→ν[over ¯]_{e} candidates with a background of 10.3 and 102 ν[over ¯]_{μ}→ν[over ¯]_{μ} candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm_{32}^{2}|=2.48_{-0.06}^{+0.11}×10^{-3} eV^{2}/c^{4} and sin^{2}θ_{23} in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δ_{CP}=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ_{23} values in the upper octant by 1.6σ
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Observation of seasonal variation of atmospheric multiple-muon events in the NOvA Near Detector
Using two years of data from the NOvA Near Detector at Fermilab, we report a seasonal variation of cosmic ray induced multiple-muon (Nμ≥2) event rates which has an opposite phase to the seasonal variation in the atmospheric temperature. The strength of the seasonal multiple-muon variation is shown to increase as a function of the muon multiplicity. However, no significant dependence of the strength of the seasonal variation of the multiple-muon variation is seen as a function of the muon zenith angle, or the spatial or angular separation between the correlated muons
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at
the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
Precision measurement of reactor antineutrino oscillation at kilometer-scale baselines by Daya Bay
We present a new determination of the smallest neutrino mixing angle
and the mass-squared difference
using a final sample of inverse beta-decay (IBD)
candidates with the final-state neutron captured on gadolinium. This sample was
selected from the complete data set obtained by the Daya Bay reactor neutrino
experiment in 3158 days of operation. Compared to the previous Daya Bay
results, selection of IBD candidates has been optimized, energy calibration
refined, and treatment of backgrounds further improved. The resulting
oscillation parameters are ,
for
the normal mass ordering or for the inverted mass ordering.Comment: 7 pages, 3 figures, 1 table, 10 supplementary file
Measurement of the double-differential muon-neutrino charged-current inclusive cross section in the NOvA near detector
We report cross-section measurements of the final-state muon kinematics for νμ charged-current interactions in the NOvA near detector using an accumulated 8.09×1020 protons on target 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, Eν, and square of the four-momentum transfer, Q2. We compare the results to inclusive cross-section predictions from various neutrino event generators via χ2 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 Q2, indicating a missing suppression of the cross section in current neutrino-nucleus scattering models
Search for slow magnetic monopoles with the NOvA detector on the surface
We report a search for a magnetic monopole component of the cosmic-ray flux in a 95-day exposure
of the NOvA experiment’s Far Detector, a 14 kt segmented liquid scintillator detector designed primarily to
observe GeV-scale electron neutrinos. No events consistent with monopoles were observed, setting an
upper limit on the flux of 2 × 10−14 cm−2 s−1 sr−1 at 90% C.L. for monopole speed 6 × 10−4 < β <
5 × 10−3 and mass greater than 5 × 108 GeV. Because of NOvA’s small overburden of 3 meters-water
equivalent, this constraint covers a previously unexplored low-mass region
First measurement of electron neutrino appearance in NOvA
We report results from the first search for νμ→νe transitions by the NOvA experiment. In an exposure equivalent to 2.74×1020 protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δCP<0.5π in the inverted mass hierarchy at the 90% C.L
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