36 research outputs found

    Search for slow magnetic monopoles with the NOvA detector on the surface

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    We report a search for a magnetic monopole component of the cosmic-ray flux in a 95-day exposure of the NOvA experimentā€™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 Ɨ 10āˆ’14 cmāˆ’2 sāˆ’1 srāˆ’1 at 90% C.L. for monopole speed 6 Ɨ 10āˆ’4 < Ī² < 5 Ɨ 10āˆ’3 and mass greater than 5 Ɨ 108 GeV. Because of NOvAā€™s small overburden of 3 meters-water equivalent, this constraint covers a previously unexplored low-mass region

    First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA

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    The NOvA experiment has seen a 4.4Ļƒ signal of Ī½Ģ„e appearance in a 2 GeV Ī½Ģ„Ī¼ beam at a distance of 810 km. Using 12.33Ɨ1020 protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 Ī½Ģ„Ī¼ā†’Ī½Ģ„e candidates with a background of 10.3 and 102 Ī½Ģ„Ī¼ā†’Ī½Ģ„Ī¼ candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Ī”m322|=2.48-0.06+0.11Ɨ10-3 eV2/c4 and sin2Īø23 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 Ī“CP=Ļ€/2 for the inverted mass hierarchy by more than 3Ļƒ and favor the normal neutrino mass hierarchy by 1.9Ļƒ and Īø23 values in the upper octant by 1.6Ļƒ

    First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA

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    The NOvA experiment has seen a 4.4 Ļƒ signal of ĀÆ Ī½ e appearance in a 2 GeV ĀÆ Ī½ Ī¼ beam at a distance of 810 km. Using 12.33 Ɨ 10 20 protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ĀÆ Ī½ Ī¼ ā†’ ĀÆ Ī½ e candidates with a background of 10.3 and 102 ĀÆ Ī½ Ī¼ ā†’ ĀÆ Ī½ Ī¼ candidates. This new antineutrino data are combined with neutrino data to measure the parameters | Ī” m 2 32 | = 2.4 8 + 0.11 āˆ’ 0.06 Ɨ 10 āˆ’ 3 ā€‰ ā€‰ eV 2 / c 4 and sin 2 Īø 23 in the ranges from (0.53ā€“0.60) and (0.45ā€“0.48) in the normal neutrino mass hierarchy. The data exclude most values near Ī“ C P = Ļ€ / 2 for the inverted mass hierarchy by more than 3 Ļƒ and favor the normal neutrino mass hierarchy by 1.9 Ļƒ and Īø 23 values in the upper octant by 1.6 Ļƒ

    Measurement of neutrino-induced neutral-current coherent Ļ€0 production in the NOvA near detector

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    The cross section of neutrino-induced neutral-current coherent Ļ€0 production on a carbon-dominated target is measured in the NOvA near detector. This measurement uses a narrow-band neutrino beam with an average neutrino energy of 2.7 GeV, which is of interest to ongoing and future long-baseline neutrino oscillation experiments. The measured, flux-averaged cross section is Ļƒ=13.8Ā±0.9(stat)Ā±2.3(syst)Ɨ10āˆ’40cm2/nucleus, consistent with model prediction. This result is the most precise measurement of neutral-current coherent Ļ€0 production in the few-GeV neutrino energy region

    Limits on active to sterile neutrino oscillations from disappearance searches in the MINOS, Daya Bay, and bugey-3 experiments

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    Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^2 2ĪøĪ¼e are set over 6 orders of magnitude in the sterile mass-squared splitting Ī”m^2 41. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Ī”m^2 41 < 0.8 eV^2 at 95% CLs

    ICAR: endoscopic skullā€base surgery

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