292 research outputs found

    A low energy optimization of the CERN-NGS neutrino beam for a theta_{13} driven neutrino oscillation search

    Full text link
    The possibility to improve the CERN to Gran Sasso neutrino beam performances for theta_{13} searches is investigated. We show that by an appropriate optimization of the target and focusing optics of the present CNGS design, we can increase the flux of low energy neutrinos by about a factor 5 compared to the current tau optimized focalisation. With the ICARUS 2.35 kton detector at LNGS and in case of negative result, this would allow to improve the limit to sin^22 theta_{13} by an order of magnitude better than the current limit of CHOOZ at Delta m^2 approximately 3 times 10^{-3} eV^2 within 5 years of nominal CNGS running. This is by far the most sensitive setup of the currently approved long-baseline experiments and is competitive with the proposed JHF superbeam.Comment: 19 pages, 8 figure

    Complications associated with distraction osteogenesis for infected nonunion of the femoral shaft in the presence of a bone defect A RETROSPECTIVE SERIES

    Get PDF
    We undertook a retrospective study of 50 consecutive patients (41 male, 9 female) with an infected nonunion and bone defect of the femoral shaft who had been treated by radical debridement and distraction osteogenesis. Their mean age was 29.9 years (9 to 58) and they had a mean of 3.8 (2 to 19) previous operations. They were followed for a mean of 5.9 years (2.0 to 19.0). the mean duration of the distraction osteogenesis was 24.5 months (2 to 39). Pin-track infection was observed in all patients. the range of knee movement was reduced and there was a mean residual leg-length discrepancy of 1.9 cm (0 to 8) after treatment. One patient required hip disarticulation to manage intractable sepsis. in all, 13 patients had persistant pain. Bony union was achieved in 49 patients at a mean of 20.7 months (12 to 35).Although distraction osteogenesis is commonly used for the treatment of infected femoral nonunion with bone defects, it is associated with a high rate of complications.Universidade Federal de SĂŁo Paulo, Dept Orthopaed & Traumatol, BR-04038032 SĂŁo Paulo, BrazilUniversidade Federal de SĂŁo Paulo, Dept Orthopaed & Traumatol, BR-04038032 SĂŁo Paulo, BrazilWeb of Scienc

    Neutrino oscillation physics at an upgraded CNGS with large next generation liquid Argon TPC detectors

    Get PDF
    The determination of the missing Ue3U_{e3} element (magnitude and phase) of the PMNS neutrino mixing matrix is possible via the detection of \numu\to\nue oscillations at a baseline LL and energy EE given by the atmospheric observations, corresponding to a mass squared difference E/L∌Δm2≃2.5×10−3eV2E/L \sim \Delta m^2\simeq 2.5\times 10^{-3} eV^2. While the current optimization of the CNGS beam provides limited sensitivity to this reaction, we discuss in this document the physics potential of an intensity upgraded and energy re-optimized CNGS neutrino beam coupled to an off-axis detector. We show that improvements in sensitivity to Ξ13\theta_{13} compared to that of T2K and NoVA are possible with a next generation large liquid Argon TPC detector located at an off-axis position (position rather distant from LNGS, possibly at shallow depth). We also address the possibility to discover CP-violation and disentangle the mass hierarchy via matter effects. The considered intensity enhancement of the CERN SPS has strong synergies with the upgrade/replacement of the elements of its injector chain (Linac, PSB, PS) and the refurbishing of its own elements, envisioned for an optimal and/or upgraded LHC luminosity programme.Comment: 37 pages, 20 figure

    Site Layout of the proposed new Hadrons' Injector Chain at CERN

    Get PDF
    The replacement of almost all the LHC injector complex on the Meyrin-site of CERN (Linac2, PSB and PS) is planned within the next 10 years. The layout foreseen for the new accelerators is described in this paper, together with its compatibility with the existing experimental physics facilities. These machines can, after upgrade, supply with high beam power future physics facilities for radioactive ions and/or neutrinos. Their possible layout is also sketched in this document

    Underground Neutrino Detectors for Particle and Astroparticle Science: the Giant Liquid Argon Charge Imaging ExpeRiment (GLACIER)

    Full text link
    The current focus of the CERN program is the Large Hadron Collider (LHC), however, CERN is engaged in long baseline neutrino physics with the CNGS project and supports T2K as recognized CERN RE13, and for good reasons: a number of observed phenomena in high-energy physics and cosmology lack their resolution within the Standard Model of particle physics; these puzzles include the origin of neutrino masses, CP-violation in the leptonic sector, and baryon asymmetry of the Universe. They will only partially be addressed at LHC. A positive measurement of sin⁥22Ξ13>0.01\sin^22\theta_{13}>0.01 would certainly give a tremendous boost to neutrino physics by opening the possibility to study CP violation in the lepton sector and the determination of the neutrino mass hierarchy with upgraded conventional super-beams. These experiments (so called ``Phase II'') require, in addition to an upgraded beam power, next generation very massive neutrino detectors with excellent energy resolution and high detection efficiency in a wide neutrino energy range, to cover 1st and 2nd oscillation maxima, and excellent particle identification and π0\pi^0 background suppression. Two generations of large water Cherenkov detectors at Kamioka (Kamiokande and Super-Kamiokande) have been extremely successful. And there are good reasons to consider a third generation water Cherenkov detector with an order of magnitude larger mass than Super-Kamiokande for both non-accelerator (proton decay, supernovae, ...) and accelerator-based physics. On the other hand, a very massive underground liquid Argon detector of about 100 kton could represent a credible alternative for the precision measurements of ``Phase II'' and aim at significantly new results in neutrino astroparticle and non-accelerator-based particle physics (e.g. proton decay).Comment: 31 pages, 14 figure

    Statistical Pattern Recognition: Application to ΜΌ→Μτ\nu_{\mu}\to\nu_{\tau} Oscillation Searches Based on Kinematic Criteria

    Full text link
    Classic statistical techniques (like the multi-dimensional likelihood and the Fisher discriminant method) together with Multi-layer Perceptron and Learning Vector Quantization Neural Networks have been systematically used in order to find the best sensitivity when searching for ΜΌ→Μτ\nu_\mu \to \nu_{\tau} oscillations. We discovered that for a general direct Μτ\nu_\tau appearance search based on kinematic criteria: a) An optimal discrimination power is obtained using only three variables (EvisibleE_{visible}, PTmissP_{T}^{miss} and ρl\rho_{l}) and their correlations. Increasing the number of variables (or combinations of variables) only increases the complexity of the problem, but does not result in a sensible change of the expected sensitivity. b) The multi-layer perceptron approach offers the best performance. As an example to assert numerically those points, we have considered the problem of Μτ\nu_\tau appearance at the CNGS beam using a Liquid Argon TPC detector.Comment: 24 pages, 15 figure

    The CERN Neutrino beam to Gran Sasso (NGS)

    Get PDF
    The conceptual technical design of the NGS (CERN neutrino beam to Gran Sasso) facility has been presented in the report CERN 98-02 / INFN-AE/98-05. Additional information, in particular an update on various neutrino beam options for the NGS facility, has been provided in a memorandum to the CERN-SPSC Committee (CERN-SPSC/98-35). In the present report, further improvements on the NGS design and performance, in particular new scenarios for SPS proton cycles for NGS operation and a new version of the NGS "high energy" neutrino beam for nt appearance experiments, are described. This new NGS reference beam is estimated to provide three times more nt events per year than the beam presented in the 1998 report. The radiological aspects of the NGS facility have been re-examined with the new beam design. An updated version of the construction schedule is also presented
    • 

    corecore