Measurement of the ν_{e}-Nucleus Charged-Current Double-Differential Cross Section at ⟨E_{ν}⟩=2.4 GeV Using NOvA.

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10^{20} protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃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≤E_{ν}<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}.

New insights into NO adsorption on alkali metal and transition metal doped graphene nanoribbon surface: A DFT approach.

The aim of this article is to investigate the sensing performance of NO gas molecule on the graphene nanoribbon domain for the determination of structural and electronic properties. Effect of an alkali metal (lithium) and a transition metal (iron) on the armchair oriented graphene nanoribbon (ArGNR) surface for the sensing purpose of NO gas has been performed through the quantum mechanics based Density Functional Theory (DFT) calculations. Various configurations of ArGNR doped with Li and Fe atoms such as one-edge doped, center doped, both-edge doped Li-ArGNR and Fe-ArGNR have been simulated, and a detailed comparative study of lithium and iron doping on different configurations of ArGNRs for the adsorption energy, stability analysis, band gap analysis and density of states analysis has been quantitatively evaluated. By comparing the adsorption energy of NO, it is found that Li doping enhances the strength of NO adsorption on the different variants of ArGNR. Computational results predict that the undoped ArGNR is insensitive to the NO gas adsorption with adsorption energy of about -0.41 eV. Our results determine that substitutional doping of Li doping at one edge doped and both-edge doped position increases the adsorption abilities of ArGNRs in these configurations with adsorption energies of approximately -6.92 eV and -9.64 eV that is 16 and 23 times greater than the pristine ArGNR (Pr-ArGNR). Band nature for both type of doping estimates the changing behavior of ArGNRs from semiconductor to metallic transition after the adsorption of NO molecule. It is concluded that the Li doping at one edge and both edge position of ArGNR makes it an excellent potential sensing material for the sensing purpose of NO gas as compared to the Fe doped configurations.

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 12.51×10^{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 ν[over ¯]_{µ}→ν[over ¯]_{s} oscillation is observed. Interpreting this result within a 3+1 model, constraints are placed on the mixing angles θ_{24}<25° and θ_{34}<32° at the 90% C.L. for 0.05 eV^{2}≤Δm_{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.

Defective GaAs nanoribbon-based biosensor for lung cancer biomarkers: a DFT study.

Density functional theory-based first-principles investigation is performed on pristine and mono vacancy induced GaAs nanoribbons to detect the presence of three volatile organic compounds (VOCs), aniline, isoprene and o-toluidine, which will aid in sensing lung cancer. The study has shown that pristine nanoribbon senses all three analytes. For the pristine structure, we observe decent adsorbing parameters and the bandgap widens after the adsorption of analytes. However, the introduction of the carrier traps induced by defect causes deep energy wells that vary the electrical properties as indicated in the bandgap analysis of GaAs, wherein adsorption of aniline and o-toluidine reduces the bandgap to 0 eV, making the structure highly conductive in nature. The adsorption energies of defect-induced nanoribbon are more as compared with the pristine counterpart. Nonetheless, the introduction of defects has improved the sensitivity further.

Analysis of uric acid adsorption on armchair silicene nanoribbons: a DFT study.

Density functional theory based first-principles investigation study is done on armchair silicene nanoribbons (ASiNRs) for adsorption of uric acid molecule. Pristine and defect-induced variants of ASiNR are considered, and the electronic and transport properties are calculated with the adsorption. The pristine ASiNR with zero band gap is engineered with defect to create a band gap, and a significant change in the band structure of defective ASiNR after the adsorption is observed. The adsorption energy of the defective complex is calculated as - 9.21 eV which is more compared to that of the pristine counterpart, whose adsorption energy comes out to be 7.76 eV. The study shows that introduction of defect reduced the sensitivity of ASiNR toward uric acid molecule.

First principles investigation on armchair zinc oxide nanoribbons as uric acid sensors.

A study is done to check the sensing functionality of armchair zinc oxide (ZnO) nanoribbon towards uric acid. The main focus of the research is to observe the change in the electronic properties (adsorption energy, bandstructure and density of states) and transport properties (current-voltage characteristics) of nanoribbon on adsorption of uric acid. In this work, two armchair ZnO nanoribbons of width, N = 4 and 6 atoms are used, and additional variations are created in the nanoribbon by introducing defect and doping agent. Manganese is used as a dopant. The work reveals that chemisorption occurs only in the case of doping for both widths of nanoribbons, and there is an enormous increase in the conductivity of defective armchair ZnO nanoribbon with width, N = 6 as compared to others on adsorption of uric acid. All calculations are carried out using density functional theory (DFT) and non-equilibrium Green's function (NEGF). Graphical abstract.

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.

Constraints on Oscillation Parameters from ν_{e} Appearance and ν_{µ} Disappearance in NOvA.

Results are reported from an improved measurement of ν_{µ}→ν_{e} transitions by the NOvA experiment. Using an exposure equivalent to 6.05×10^{20} protons on target, 33 ν_{e} candidates are observed with a background of 8.2±0.8 (syst.). Combined with the latest NOvA ν_{µ} disappearance data and external constraints from reactor experiments on sin^{2}2θ_{13}, the hypothesis of inverted mass hierarchy with θ_{23} in the lower octant is disfavored at greater than 93% C.L. for all values of δ_{CP}.

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA.

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3} eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

First Measurement of Electron Neutrino Appearance in NOvA.

We report results from the first search for ν_{µ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} 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<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

First direct observation of muon antineutrino disappearance.

This Letter reports the first direct observation of muon antineutrino disappearance. The MINOS experiment has taken data with an accelerator beam optimized for ν(µ) production, accumulating an exposure of 1.71 × 10²° protons on target. In the Far Detector, 97 charged current ν(µ) events are observed. The no-oscillation hypothesis predicts 156 events and is excluded at 6.3σ. The best fit to oscillation yields |Δm²| = [3.36(-0.40)(+0.46)(stat) ± 0.06(syst)] × 10⁻³ eV², sin²(2θ) = 0.86(-0.12)(+0.11)(stat) ± 0.01(syst). The MINOS ν(µ) and ν(µ) measurements are consistent at the 2.0% confidence level, assuming identical underlying oscillation parameters.

Measurement of the neutrino mass splitting and flavor mixing by MINOS.

Measurements of neutrino oscillations using the disappearance of muon neutrinos from the Fermilab NuMI neutrino beam as observed by the two MINOS detectors are reported. New analysis methods have been applied to an enlarged data sample from an exposure of 7.25×10(20) protons on target. A fit to neutrino oscillations yields values of |Δm(2)|=(2.32(-0.08)(+0.12))×10(-3) eV(2) for the atmospheric mass splitting and sin(2)(2θ)>0.90 (90% C.L.) for the mixing angle. Pure neutrino decay and quantum decoherence hypotheses are excluded at 7 and 9 standard deviations, respectively.

Search for Lorentz invariance and CPT violation with the MINOS far detector.

We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be a consequence of Lorentz and CPT violation as described by the standard-model extension framework. It also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We found no evidence for this sidereal signature, and the upper limits placed on the magnitudes of the Lorentz and CPT violating coefficients describing the theory are an improvement by factors of 20-510 over the current best limits found by using the MINOS near detector.

Measurement of numicro and nue events in an off-axis horn-focused neutrino beam.

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 degrees) with respect to the NuMI beam axis. Samples of charged-current quasielastic numicro and nue 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.

Search for muon-neutrino to electron-neutrino transitions in MINOS.

This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 and sin2(2theta(23))=1.0 are assumed.

Search for active neutrino disappearance using neutral-current interactions in the MINOS long-baseline experiment.

We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.

Testing Lorentz invariance and CPT conservation with NuMI neutrinos in the MINOS near detector.

A search for a sidereal modulation in the MINOS near detector neutrino data was performed. If present, this signature could be a consequence of Lorentz and CPT violation as predicted by the effective field theory called the standard-model extension. No evidence for a sidereal signal in the data set was found, implying that there is no significant change in neutrino propagation that depends on the direction of the neutrino beam in a sun-centered inertial frame. Upper limits on the magnitudes of the Lorentz and CPT violating terms in the standard-model extension lie between 10(-4) and 10(-2) of the maximum expected, assuming a suppression of these signatures by a factor of 10(-17).

Measurement of neutrino oscillations with the MINOS detectors in the NuMI beam.

This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Deltam2| = (2.43+/-0.13) x 10(-3) eV2 (68% C.L.) and mixing angle sin2(2theta) > 0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively.

Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam.

This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).