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 \numu charged-current interactions in the NOvA near detector using an accumulated 8.09$\times10^{20}$ 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, $E_\nu$, and square of the four-momentum transfer, $Q^2$. We compare the results to inclusive cross-section predictions from various neutrino event generators via $\chi^2$ 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 $Q^2$, indicating a missing suppression of the cross section in current neutrino-nucleus scattering models

Measurement of the νe−\nu_e-Nucleus Charged-Current Double-Differential Cross Section at <Eν>=\left< E_{\nu} \right> = 2.4 GeV using NOvA

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using $8.02\times10^{20}$ protons-on-target (POT) in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by $\simeq$ 17\% systematic rather than the $\simeq$ 7.4\% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on $Q^{2}$ (squared four-momentum transfer) and energy, in the range 1 GeV $\leq E_{\nu} <$6 GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs. $Q^{2}$

Seasonal variation of multiple-muon cosmic ray air showers observed in the NOvA detector on the surface

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 and 230 K and 940 mbar and 990 mbar, respectively; the shower rates are anticorrelated 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

Extended search for supernovalike neutrinos in NOvA coincident with LIGO/Virgo detections

A search is performed for supernovalike 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 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

Improved measurement of neutrino oscillation parameters by the NOvA experiment

We present new nu(mu) -> nu(e), nu(mu) -> nu(mu), (nu) over bar (mu) -> (nu) over bar (e), and (nu) over bar (mu) -> (nu) over bar (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 nu(e), nu(mu), (nu) over bar (e), and (nu) over bar (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 theta(23) mixing angle, with Delta m(32)(2) = (2.41 +/- 0.07) x 10(-3) eV(2) and sin(2)theta(23) = 0.57(-0.04)(+0.03). The data disfavor combinations of oscillation parameters that give rise to a large asymmetry in the rates of nu(e) and (nu) over bar (e) appearance. This includes values of the charge parity symmetry (CP) violating phase in the vicinity of delta(CP) = pi/2 which arc excluded by > 3 sigma for the inverted mass ordering, and values around delta(CP) = 3 pi/2 in the normal ordering which are disfavored at 2 sigma confidence

Search for Active-Sterile Antineutrino Mixing Using Neutral-Current Interactions with the NOvA Experiment

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51 x 10(20) protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122 +/- 11(stat.) 15(syst.) assuming mixing only between three active flavors. No evidence for (v) over bar (mu)-> (v) over bar (s) oscillation is observed. Interpreting this result within a 3 + 1 model, constraints are placed on the mixing angles theta(24) < 25 degrees and theta(34) < 32 degrees at the 90% C.L. for 0.05 eV(2) <= Delta m(41)(2) <= 0.5 eV(2), the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3 + 1 confidence limits set using long-baseline accelerator antineutrinos