1,166 research outputs found

    Precision on leptonic mixing parameters at future neutrino oscillation experiments

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    We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta_{13} and the CP phase, delta, assuming that theta_{13} is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effect, the comparison of the physics reach of different experiments on the basis of the CP discovery potential, as usually done, can be misleading. We have compared various proposed super-beam, beta-beam and neutrino factory setups on the basis of the relative precision of theta_{13} and the error on delta. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on theta_{13} below 3% and an error on delta of < 7^{\circ} at 1 sigma (1 d.o.f.) can be obtained at a neutrino factory.Comment: Minor changes, matches version accepted in JHEP. 30 pages, 9 figure

    Potential of optimized NOvA for large theta(13) & combined performance with a LArTPC & T2K

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    NOvA experiment has reoptimized its event selection criteria in light of the recently measured moderately large value of theta(13). We study the improvement in the sensitivity to the neutrino mass hierarchy and to leptonic CP violation due to these new features. For favourable values of deltacp, NOvA sensitivity to mass hierarchy and leptonic CP violation is increased by 20%. Addition of 5 years of neutrino data from T2K to NOvA more than doubles the range of deltacp for which the leptonic CP violation can be discovered, compared to stand alone NOvA. But for unfavourable values of deltacp, the combination of NOvA and T2K are not enough to provide even a 90% C.L. hint of hierarchy discovery. Therefore, we further explore the improvement in the hierarchy and CP violation sensitivities due to the addition of a 10 kt liquid argon detector placed close to NOvA site. The capabilities of such a detector are equivalent to those of NOvA in all respects. We find that combined data from 10 kt liquid argon detector (3 years of nu + 3 years of nubar run), NOvA (6 years of nu + 6 years of nubar run) and T2K (5 years of nu run) can give a close to 2 sigma hint of hierarchy discovery for all values of deltacp. With this combined data, we can achieve CP violation discovery at 95% C.L. for roughly 60% values of deltacp.Comment: 22 pages, 24 pdf figures, 5 tables. In the appendix, new results are presented with conservative choices of central values of oscillation parameters. New references are added. Accepted in JHE

    Antibacterial effect of a fluoride-containing ZnO/CuO nanocomposite

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    © 2019 Elsevier B.V. Dental materials that are antimicrobial and acid-resistant can inhibit bacterial colonization and demineralization, thereby preventing caries. Zinc and copper are well-known for their antibacterial effect, as is nanostructured ZnO–CuO composite. Minerals such as fluorine and calcium, can remineralize and demineralize teeth. Therefore, we developed novel fluoride-containing ZnO–CuO (ZCF) nanocomposites; to the best of our knowledge, these are the first nanocomposites of this kind. The fluoride concentrations and antibacterial effects of the ZCF nanocomposites were evaluated. Nanocomposites comprising zinc and copper (ZC), and zinc, copper, and fluorine (ZCF), were prepared by a simple one-step homogeneous coprecipitation method at a low temperature (80 °C), without the use of organic solvent or surfactant. The structure and composition of the ZC and ZCF nanocomposites were examined by scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS). Quantitative analysis of the mass concentration was performed by using ZAF correction methods. The fluorine content in nanocomposites was evaluated by using proton-induced gamma emission (PIGE) at the Takasaki Advanced Radiation Research Institute in Japan. By using 96-well microtiter plates, we analyzed the antibiotic susceptibility of ZC, ZCF, and the control buffer (phosphate-buffered saline) with Streptococcus mutans (ATCC 25175). The SEM images showed that ZC and ZCF nanocomposites were composed of 3D flower-like microstructures with diameters of approximately 1 μm. Environmental SEM-EDS analysis revealed that ZC contained 43.2% Cu, 55.1% Zn, 2.2% F, and 0.1% Cl, whereas ZCF contained 47.5% Cu, 40.5% Zn, 6.7% F, and 5.9% Cl. Analysis by PIGE showed that ZCF nanocomposite contained 2553.6 ± 199.2 ppm fluorine, whereas no fluoride was detected in ZC. The control buffer enabled bacterial growth to 4 × 107 ± 9 × 106 CFU/mL, whereas ZC allowed growth of 12 ± 8 CFU/mL, and ZCF showed no bacterial growth. Thus, we developed novel fluoride-containing ZnO–CuO nanocomposites, which exhibited antibacterial effects and have the potential for remineralization, thereby demonstrating their potential as multifunctional dental materials

    Study of the Baryon-Antibaryon Low-Mass Enhancements in Charmless Three-body Baryonic B Decays

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    The angular distributions of the baryon-antibaryon low-mass enhancements seen in the charmless three-body baryonic B decays B+ -> p pbar K+, B0 -> p pbar Ks, and B0 -> p Lambdabar pi- are reported. A quark fragmentation interpretation is supported, while the gluonic resonance picture is disfavored. Searches for the Theta+ and Theta++ pentaquarks in the relevant decay modes and possible glueball states G with 2.2 GeV/c2 < M-ppbar < 2.4 GeV/c2 in the ppbar systems give null results. We set upper limits on the products of branching fractions, B(B0 -> Theta+ p)\times B(Theta+ -> p Ks) Theta++ pbar) \times B(Theta++ -> p K+) G K+) \times B(G -> p pbar) < 4.1 \times 10^{-7} at the 90% confidence level. The analysis is based on a 140 fb^{-1} data sample recorded on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.Comment: 14 pages, 13 figure files, update of hep-ex/0409010 for journal submisssio

    Probing the Neutrino Mass Hierarchy with Super-Kamiokande

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    We show that for recently discovered large values of theta(13), a superbeam with an average neutrino energy of ~ 5 GeV, such as those being proposed at CERN, if pointing to Super-Kamiokande (L = 8770 km), could reveal the neutrino mass hierarchy at 5 sigma in less than two years irrespective of the true hierarchy and CP phase. The measurement relies on the near resonant matter effect in the numu to nue oscillation channel, and can be done counting the total number of appearance events with just a neutrino beam.Comment: 16 pages, 7 pdf figures, 2 tables. Format changed and text extended. Four new pdf figures added. Dependency of the result on 1-3 mixing angle discussed. Conclusions unchanged. Accepted in JHE

    Mass hierarchy discrimination with atmospheric neutrinos in large volume ice/water Cherenkov detectors

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    Large mass ice/water Cherenkov experiments, optimized to detect low energy (1-20 GeV) atmospheric neutrinos, have the potential to discriminate between normal and inverted neutrino mass hierarchies. The sensitivity depends on several model and detector parameters, such as the neutrino flux profile and normalization, the Earth density profile, the oscillation parameter uncertainties, and the detector effective mass and resolution. A proper evaluation of the mass hierarchy discrimination power requires a robust statistical approach. In this work, the Toy Monte Carlo, based on an extended unbinned likelihood ratio test statistic, was used. The effect of each model and detector parameter, as well as the required detector exposure, was then studied. While uncertainties on the Earth density and atmospheric neutrino flux profiles were found to have a minor impact on the mass hierarchy discrimination, the flux normalization, as well as some of the oscillation parameter (\Delta m^2_{31}, \theta_{13}, \theta_{23}, and \delta_{CP}) uncertainties and correlations resulted critical. Finally, the minimum required detector exposure, the optimization of the low energy threshold, and the detector resolutions were also investigated.Comment: 23 pages, 16 figure

    Repressing Anarchy in Neutrino Mass Textures

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    The recent results that θ13\theta_{13} is relatively large, of the order of the previous upper bound, and the indications of a sizable deviation of θ23\theta_{23} from the maximal value are in agreement with the predictions of Anarchy in the lepton sector. The quark and charged lepton hierarchies can then be reproduced in a SU(5) GUT context by attributing non-vanishing U(1)FNU(1)_{FN} charges, different for each family, only to the SU(5) tenplet states. The fact that the observed mass hierarchies are stronger for up quarks than for down quarks and charged leptons supports this idea. As discussed in the past, in the flexible context of SU(5)U(1)FNSU(5)\otimes U(1)_{FN}, different patterns of charges can be adopted going from Anarchy to various types of hierarchy. We revisit this approach by also considering new models and we compare all versions to the present data. As a result we confirm that, by relaxing the extreme ansatz of equal U(1)FNU(1)_{FN} charges for all SU(5) pentaplets and singlets, better agreement with the data than for Anarchy is obtained without increasing the model complexity. We also present the distributions obtained in the different models for the Dirac CP-violating phase. Finally we discuss the relative merits of these simple models.Comment: v1: 12 pages, 3 figures; v2: 13 pages, 3 figures, text improved, matches version accepted for publication; v3: submitted to add an acknowledgment to a networ

    Progress toward universal health coverage. A comparative analysis in 5 South Asian countries

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    Importance: Achieving universal health coverage is one of the key targets in the newly adopted Sustainable Development Goals of the United Nations. Objective: To investigate progress toward universal health coverage in 5 South Asian countries and assess inequalities in health services and financial risk protection indicators. Design and Settings: In a population-based study, nationally representative household (335 373 households) survey data from Afghanistan (2014 and 2015), Bangladesh (2010 and 2014), India (2012 and 2014), Nepal (2014 and 2015), and Pakistan (2014) were used to calculate relative indices of health coverage, financial risk protection, and inequality in coverage among wealth quintiles. The study was conducted from June 2012 to February 2016. Main Outcomes and Measures: Three dimensions of universal health coverage were assessed: access to basic services, financial risk protection, and equity. Composite and indicator-specific coverage rates, stratified by wealth quintiles, were then estimated. Slope and relative index of inequality were used to assess inequalities in service and financial indicators. Results Access to basic care varied substantially across all South Asian countries, with mean rates of overall prevention coverage and treatment coverage of 53.0% (95% CI, 42.2%-63.6%) and 51.2% (95% CI, 45.2%-57.1%) in Afghanistan, 76.5% (95% CI, 61.0%-89.0%) and 44.8% (95% CI, 37.1%-52.5%) in Bangladesh, 74.2% (95% CI, 57.0%-88.1%) and 83.5% (95% CI, 54.4%-99.1%) in India, 76.8% (95% CI, 66.5%-85.7%) and 57.8% (95% CI, 50.1%-65.4%) in Nepal, and 69.8% (95% CI, 58.3%-80.2%) and 50.4% (95% CI, 37.1%-63.6%) in Pakistan. Financial risk protection was generally low, with 15.3% (95% CI, 14.7%-16.0%) of respondents in Afghanistan, 15.8% (95% CI, 14.9%-16.8%) in Bangladesh, 17.9% (95% CI, 17.7%-18.2%) in India, 11.8% (95% CI, 11.8%-11.9%) in Nepal, and 4.4% (95% CI, 4.0%-4.9%) in Pakistan reporting incurred catastrophic payments due to health care costs. Access to at least 4 antenatal care visits, institutional delivery, and presence of skilled attendant during delivery were at least 3 times higher among the wealthiest mothers in Afghanistan, Bangladesh, Nepal, and Pakistan compared with the rates among poor mothers. Access to institutional delivery was 60 to 65 percentage points higher among wealthy than poor mothers in Afghanistan, Bangladesh, Nepal, and Pakistan compared with 21 percentage points higher in India. Coverage was least equitable among the countries for adequate sanitation, institutional delivery, and the presence of skilled birth attendants. Conclusions and Relevance: Health coverage and financial risk protection was low, and inequality in access to health care remains a serious issue for these South Asian countries. Greater progress is needed to improve treatment and preventive services and financial security
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