142 research outputs found

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

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    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 F29(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

    Search for active-sterile neutrino mixing using neutral-current interactions in NOvA

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    We report results from the first search for sterile neutrinos mixing with active neutrinos through a reduction in the rate of neutral-current interactions over a baseline of 810 km between the NOvA detectors. Analyzing a 14-kton detector equivalent exposure of 6.05 x 10(20) protons-on-target in the NuMI beam at Fermilab, we observe 95 neutral-current candidates at the Far Detector compared with 83.5 +/- 9.7(stat) +/- 9.4(syst) events predicted assuming mixing only occurs between active neutrino species. No evidence for upsilon(mu) -\u3e upsilon(mu) transitions is found. Interpreting these results within a 3 + 1 model, we place constraints on the mixing angles theta(24) \u3c 20.8 degrees and theta(34) \u3c 31.2 degrees at the 90% C.L. for 0.05 eV(2) \u3c= Delta m(41)(2) \u3c= 0.5 eV(2), the range of mass splittings that produce no significant oscillations over the Near Detector baseline

    Measurement of the Neutrino Mixing Angle theta(23) in NOvA

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    This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05 x 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 theta(23) mixing (theta(23) = pi/4). Assuming the normal mass hierarchy, we find Delta m(32)(2) = (2.67 +/- 0.11) x 10(-3) eV(2) and sin(2) theta(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 2.6 sigma significance

    Constraints on Oscillation Parameters from nu(e) Appearance and nu(mu) Disappearance in NOvA

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    Results are reported from an improved measurement of nu(mu) -\u3e nu(e) transitions by the NOvA experiment. Using an exposure equivalent to 6.05 x 10(20) protons on target, 33 nu(e) candidates are observed with a background of 8.2 +/- 0.8 (syst.). Combined with the latest NOvA nu(mu) disappearance data and external constraints from reactor experiments on sin(2) 2 theta(13), the hypothesis of inverted mass hierarchy with theta(23) in the lower octant is disfavored at greater than 93% C.L. for all values of delta(CP)

    The progressive elevation of alpha fetoprotein for the diagnosis of hepatocellular carcinoma in patients with liver cirrhosis

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    BACKGROUND: Hepatocellular carcinoma is the most common cause of primary liver neoplasms and is one of the main causes of death in patients with liver cirrhosis. High Alpha fetoprotein serum levels have been found in 60–70% of patients with Hepatocellular carcinoma; nevertheless, there are other causes that increase this protein. Alpha fetoprotein levels ≥200 and 400 ng/mL in patients with an identifiable liver mass by imaging techniques are diagnostic of hepatocellular carcinoma with high specificity. METHODS: We analysed the sensitivity and specificity of the progressive increase of the levels of alpha fetoprotein for the detection of hepatocellular carcinoma in patients with liver cirrhosis. Seventy-four patients with cirrhosis without hepatocellular carcinoma and 193 with hepatic lesions diagnosed by biopsy and shown by image scans were included. Sensitivity and specificity of transversal determination of alpha fetoprotein ≥ 200 and 400 ng/mL and monthly progressive elevation of alpha fetoprotein were analysed. Areas under the ROC curves were compared. Positive and negative predictive values adjusted to a 5 and 10% prevalence were calculated. RESULTS: For an elevation of alpha fetoprotein ≥ 200 and 400 ng/mL the specificity is of 100% in both cases, with a sensitivity of 36.3 and 20.2%, respectively. For an alpha fetoprotein elevation rate ≥7 ng/mL/month, sensitivity was of 71.4% and specificity of 100%. The area under the ROC curve of the progressive elevation was significantly greater than that of the transversal determination of alpha fetoprotein. The positive and negative predictive values modified to a 10% prevalence are of: 98.8% and 96.92%, respectively; while for a prevalence of 5% they were of 97.4% and 98.52%, respectively. CONCLUSION: The progressive elevation of alpha fetoprotein ≥7 ng/mL/month in patients with liver cirrhosis is useful for the diagnosis of hepatocellular carcinoma in patients that do not reach αFP levels ≥200 ng/mL. Prospective studies are required to confirm this observation

    Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

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    The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
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