1,448 research outputs found

    Occurrence of polychlorobiphenyls in buffalo mozzarella cheese from Campania (Italy)

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    Buffalo milk and mozzarella cheese produced in the Caserta and Salerno areas in Campania region have been investigated on the presence and the levels of polychlorobiphenyls (PCBs). Seven congeners, six non dioxin-like (NDL-PCBs nos. 28, 52, 101, 138, 153 and 180) and one dioxin-like (DL-PCB n. 118), were detected. PCBs were found at detectable levels in the 83% of the buffalo milk and in the 100% of the mozzarella cheese samples from Caserta; in those from Salerno the prevalence of contamination was 77% for milk and 73% for mozzarellas, respectively. The NDL-PCB content of mozzarellas collected in Caserta was significantly higher than that found in those from Salerno. The more diffuse congeners were PCB 28, 138 and 153 both in milk and in mozzarella cheese; PCB 118 contributed to the total PCB content for the 7% in milk and 2-3% in mozzarella cheese. On the basis of the Italian annual average consumption the contribution of mozzarella to the daily dietary intake of NDL-PCB can vary between 0.41 and 21.33 ng kg-1 bw, median value of 3.66 ng kg-1 bw. The levels of contamination in milk and dairies analyzed are similar or quite lower than those found in other European countries

    Prospects for the measurement of muon-neutrino disappearance at the FNAL-Booster

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    Neutrino physics is nowadays receiving more and more attention as a possible source of information for the long-standing problem of new physics beyond the Standard Model. The recent measurement of the mixing angle θ13\theta_{13} in the standard mixing oscillation scenario encourages us to pursue the still missing results on leptonic CP violation and absolute neutrino masses. However, puzzling measurements exist that deserve an exhaustive evaluation. The NESSiE Collaboration has been setup to undertake conclusive experiments to clarify the muon-neutrino disappearance measurements at small L/EL/E, which will be able to put severe constraints to models with more than the three-standard neutrinos, or even to robustly measure the presence of a new kind of neutrino oscillation for the first time. To this aim the use of the current FNAL-Booster neutrino beam for a Short-Baseline experiment has been carefully evaluated. This proposal refers to the use of magnetic spectrometers at two different sites, Near and Far. Their positions have been extensively studied, together with the possible performances of two OPERA-like spectrometers. The proposal is constrained by availability of existing hardware and a time-schedule compatible with the CERN project for a new more performant neutrino beam, which will nicely extend the physics results achievable at the Booster. The possible FNAL experiment will allow to clarify the current νμ\nu_{\mu} disappearance tension with νe\nu_e appearance and disappearance at the eV mass scale. Instead, a new CERN neutrino beam would allow a further span in the parameter space together with a refined control of systematics and, more relevant, the measurement of the antineutrino sector, by upgrading the spectrometer with detectors currently under R&D study.Comment: 76 pages, 52 figure

    Search for anomalies in the neutrino sector with muon spectrometers and large LArTPC imaging detectors at CERN

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    A new experiment with an intense ~2 GeV neutrino beam at CERN SPS is proposed in order to definitely clarify the possible existence of additional neutrino states, as pointed out by neutrino calibration source experiments, reactor and accelerator experiments and measure the corresponding oscillation parameters. The experiment is based on two identical LAr-TPCs complemented by magnetized spectrometers detecting electron and muon neutrino events at Far and Near positions, 1600 m and 300 m from the proton target, respectively. The ICARUS T600 detector, the largest LAr-TPC ever built with a size of about 600 ton of imaging mass, now running in the LNGS underground laboratory, will be moved at the CERN Far position. An additional 1/4 of the T600 detector (T150) will be constructed and located in the Near position. Two large area spectrometers will be placed downstream of the two LAr-TPC detectors to perform charge identification and muon momentum measurements from sub-GeV to several GeV energy range, greatly complementing the physics capabilities. This experiment will offer remarkable discovery potentialities, collecting a very large number of unbiased events both in the neutrino and antineutrino channels, largely adequate to definitely settle the origin of the observed neutrino-related anomalies.Comment: Contribution to the European Strategy for Particle Physics - Open Symposium Preparatory Group, Kracow 10-12 September 201

    Final NOMAD results on nu_mu->nu_tau and nu_e->nu_tau oscillations including a new search for nu_tau appearance using hadronic tau decays

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    Results from the nu_tau appearance search in a neutrino beam using the full NOMAD data sample are reported. A new analysis unifies all the hadronic tau decays, significantly improving the overall sensitivity of the experiment to oscillations. The "blind analysis" of all topologies yields no evidence for an oscillation signal. In the two-family oscillation scenario, this sets a 90% C.L. allowed region in the sin^2(2theta)-Delta m^2 plane which includes sin^2(2theta)<3.3 x 10^{-4} at large Delta m^2 and Delta m^2 < 0.7 eV^2/c^4 at sin^2(2theta)=1. The corresponding contour in the nu_e->nu_tau oscillation hypothesis results in sin^2(2theta)<1.5 x 10^{-2} at large Delta m^2 and Delta m^2 < 5.9 eV^2/c^4 at sin^2(2theta)=1. We also derive limits on effective couplings of the tau lepton to nu_mu or nu_e.Comment: 46 pages, 16 figures, Latex, to appear on Nucl. Phys.

    Prediction of Neutrino Fluxes in the NOMAD Experiment

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    The method developed for the calculation of the flux and composition of the West Area Neutrino Beam used by NOMAD in its search for neutrino oscillations is described. The calculation is based on particle production rates computed using a recent version of FLUKA and modified to take into account the cross sections measured by the SPY and NA20 experiments. These particles are propagated through the beam line taking into account the material and magnetic fields they traverse. The neutrinos produced through their decays are tracked to the NOMAD detector. The fluxes of the four neutrino flavours at NOMAD are predicted with an uncertainty of about 8% for nu(mu) and nu(e), 10% for antinu(mu), and 12% for antinu(e). The energy-dependent uncertainty achieved on the R(e, mu) prediction needed for a nu(mu)->nu(e) oscillation search ranges from 4% to 7%, whereas the overall normalization uncertainty on this ratio is 4.2%.Comment: 43 pages, 20 figures. Submitted to Nucl. Phys.

    Inclusive production of ρ0(770),f0(980)\rho^{0}(770), f_0(980) and f2(1270)f_2(1270) mesons in νμ\nu_{\mu} charged current interactions

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    The inclusive production of the meson resonances ρ0(770)\rho^{0}(770), f0(980)f_0(980) and f2(1270)f_2(1270) in neutrino-nucleus charged current interactions has been studied with the NOMAD detector exposed to the wide band neutrino beam generated by 450 GeV protons at the CERN SPS. For the first time the f0(980)f_{0}(980) meson is observed in neutrino interactions. The statistical significance of its observation is 6 standard deviations. The presence of f2(1270)f_{2}(1270) in neutrino interactions is reliably established. The average multiplicity of these three resonances is measured as a function of several kinematic variables. The experimental results are compared to the multiplicities obtained from a simulation based on the Lund model. In addition, the average multiplicity of ρ0(770)\rho^{0}(770) in antineutrino - nucleus interactions is measured.Comment: 23 pages, 14 figures, 8 tables. To appear in Nucl. Phys.

    Search for nu(mu)-->nu(e) Oscillations in the NOMAD Experiment

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    We present the results of a search for nu(mu)-->nu(e) oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of nu(e) in a predominantly nu(mu) wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are delta m^2 < 0.4 eV^2 for maximal mixing and sin^2(2theta) < 1.4x10^{-3} for large delta m^2. This result excludes the LSND allowed region of oscillation parameters with delta m^2 > 10 eV^2.Comment: 19 pages, 8 figures. Submitted to Phys. Lett.

    Search for the exotic Θ+\Theta^+ resonance in the NOMAD experiment

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    A search for exotic Theta baryon via Theta -> proton +Ks decay mode in the NOMAD muon neutrino DIS data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Theta signal as a function of xF which allows to study the Theta production mechanism. We do not observe any evidence for the Theta state in the NOMAD data. We provide an upper limit on Theta production rate at 90% CL as 2.13 per 1000 of neutrino interactions.Comment: Accepted to European Physics Journal
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