5,230 research outputs found

    νΟ\nu_\mu disappearance at the SPL, T2K-I and the Neutrino Factory

    Full text link
    We study the νμ\nu_\mu disappearance channel at T2K-phase I and the SPL and analyse the achievable reduction of present uncertainties in θ23\theta_{23} and Δm232\Delta m^2_{23}. We analyse the impact of discrete ambiguities in sign(Δm223\Delta m^2{23}) and sign(2tan⁡θ232 \tan \theta_{23}). We show how the disappearance channel at the Neutrino Factory is complementary to the ``golden'' and ``silver'' appearance channels and can be used to reduce the eightfold-ambiguity problem in (θ13−δ\theta_{13}-\delta).Comment: 2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascat

    Physics reach of β\beta-beams and ν\nu-factories: the problem of degeneracies

    Full text link
    We discuss the physics reach of β\beta-Beams and ν\nu-Factories from a theoretical perspective, having as a guideline the problem of degeneracies. The presence of degenerate solutions in the measure of the neutrino oscillation parameters θ13\theta_{13} and δ\delta is, in fact, the main problem that have to be addressed in planning future neutrino oscillation experiments. If degeneracies are not (at least partially) solved, it will be almost impossible to perform, at any future facility, precise measurements of θ13\theta_{13} and/or δ\delta. After a pedagogical introduction on why degenerate solutions arise and how we can get rid of them, we analyze the physics reach of current β\beta-beam and ν\nu-factory configurations. The physics reach of the "standard" \BB is severely affected by degeneracies while a better result can be obtained by higher-γ\gamma setups. At the \NF the combination of Golden and Silver channels can solve the eightfold degeneracy down to sin⁡2θ13≤10−3\sin^2\theta_{13} \le 10^{-3}Comment: 5 pages, 6 epsfig; NUFACT'05, 21-26 June 2005, Frascat

    Micro-orbits in a many-branes model and deviations from 1/r21/r^2 Newton's law

    Full text link
    We consider a 5-dimensional model with geometry M=M4×S1{\cal M} = {\cal M}_4 \times {\cal S}_1, with compactification radius RR. The Standard Model particles are localized onto a brane located at y=0, with identical branes localized at different points in the extra dimension. Objects located on our brane can orbit around objects located on a brane at a distance d=y/Rd=y/R, with an orbit and a period significantly different from the standard Newtonian ones. We study the kinematical properties of the orbits, finding that it is possible to distinguish one motion from the other in a large region of the initial conditions parameter space. This is a warm-up to study if a SM-like mass distribution on one (or more) distant brane(s) may represent a possible dark matter candidate. After using the same technique to the study of orbits of objects lying on the same brane (d=0d=0), we apply this method to detect generic deviations from the inverse-square Newton's law. We propose a possible experimental setup to look for departures from Newtonian motion in the micro-world, finding that an order of magnitude improvement on present bounds can be attained at the 95% CL under reasonable assumptions.Comment: Two-column format (20 pages), 10 figures; minor corrections and some added reference

    Degeneracies at a beta-Beam and a Super-Beam Facility

    Full text link
    The presence of degeneracies can considerably worsen the measure of the neutrino oscillation parameters θ13\theta_{13} and δ\delta. We study the physics reach of a specific ``CERN'' setup, using a standard β\beta-Beam and Super-Beam facility. These facilities have a similar sensitivity in both parameters. Their combination does not provide any dramatic improvement as expected due to their almost identical L/E ratio. We analyse if adding the correspondent disappearance channels can help in reducing the effect of degeneracies in the (θ13,δ)(\theta_{13},\delta) measure.Comment: 5 pages, 7 eps figure

    Full QCD on APE100 Machines

    Full text link
    We present the first tests and results from a study of QCD with two flavours of dynamical Wilson fermions using the Hybrid Monte Carlo Algorithm (HMCA) on APE100 machines.Comment: 23 pages, LaTeX, 13 PS figures not include

    Invisible Z decay width bounds on active-sterile neutrino mixing in the (3+1) and (3+2) models

    Full text link
    In this work we consider the standard model extended with singlet sterile neutrinos with mass in the eV range and mixed with the active neutrinos. The active-sterile neutrino mixing renders new contributions to the invisible Z decay width which, in the case of light sterile neutrinos, depends on the active-sterile mixing matrix elements only. We then use the current experimental value of the invisible Z decay width to obtain bounds on these mixing matrix elements for both (3+1) and (3+2) models.Comment: 10 pages, 5 figure

    νΟ\nu_\mu disappearance at the SPL, T2K-I, NOν\nuA and the Neutrino Factory

    Full text link
    We study the measurement of the atmospheric neutrino oscillation parameters, θ23\theta_{23} and Δm232\Delta m^2_{23}, at the νμ\nu_\mu disappearance channel at three conventional beam facilities, the SPL, T2K-phase I and NOν\nuA. These two parameters have been shown to be of crucial importance in the measurement of two of the unknowns of the PMNS mixing matrix, θ13\theta_{13} and the leptonic CP-violating phase δ\delta. In our analyis, the effect of the two discrete ambiguities, sign(Δm232){\rm sign}(\Delta m^2_{23}) and sign(tan⁡2θ23){\rm sign}(\tan 2 \theta_{23}), is explicitly taken into account. We analyse also the νμ\nu_\mu disappearance channel at the Neutrino Factory, and combine it with the ``golden'' νe→νμ\nu_e \to \nu_\mu and ``silver'' νe→ντ\nu_e \to \nu_\tau appearance channels to study its impact on the measurement of θ13\theta_{13} and δ\delta. Eventually, we present the sensitivity of the four facilities to different observables: θ13\theta_{13}, δ\delta, maximal θ23\theta_{23}, the sign of the atmospheric mass difference, satms_{atm}, and the θ23\theta_{23}-octant, socts_{oct}.Comment: 40 pages using epsfig; bibliography modifie

    Are the therapeutic strategies in anorexia of ageing effective on nutritional status? A systematic review with meta-analysis

    Get PDF
    BACKGROUND: Anorexia of ageing (AA) may be considered as a risk factor for frailty and has an important impact on quality of life, morbidity and mortality. METHODS: A systematic review and a meta-analysis were performed to summarise the results from several trials on the effectiveness of treatments in AA, as associated with depression, sensory impairment of taste and smell, decreased appetite or early satiety, and disability. Eligible studies were required to report baseline and follow-up values, the mean change (∆-change) from baseline, and/or the mean difference among intervention groups versus control group, concerning food intake (kcal/daily) and/or nutritional outcomes, such as body weight, body mass index, albumin and Mini Nutritional Assessment. RESULTS: The systematic review included 20 papers based on different therapeutic approaches concerning food intake and/or nutritional outcomes. The results of the meta-analysis indicate that the interventions for AA have an important impact on body weight [+1.59 kg; 95% confidence interval (CI) = 1.48-+1.71 kg; P < 0.001) and on energy intake (+56.09 kcal; 95% CI = -54.05 to +166.25 kcal; P = 0.32). Regarding secondary outcomes, it was not possible to meta-analyse the limited amount of data availab le. CONCLUSIONS: The different variants of AA need to be defined because diverse therapeutic approaches are available. A more precise definition of the functional impairments associated with AA may allow a more correct decision about the most appropriate therapy to be prescribed. Moreover, this may allow for a more effective performance of the different therapeutic approaches once they are better targeted to the different scenarios of AA

    Untangling CP Violation and the Mass Hierarchy in Long Baseline Experiments

    Get PDF
    In the overlap region, for the normal and inverted hierarchies, of the neutrino-antineutrino bi-probability space for νμ→νe\nu_\mu \to \nu_e appearance, we derive a simple identity between the solutions in the (sin⁡22θ13\sin^2 2\theta_{13}, sin⁡δ\sin \delta) plane for the different hierarchies. The parameter sin⁡22θ13\sin^2 2\theta_{13} sets the scale of the νμ→νe\nu_\mu \to \nu_e appearance probabilities at the atmospheric δmatm2≈2.4×10−3\delta m^2_{atm} \approx 2.4 \times 10^{-3} eV2^2 whereas sin⁡δ\sin \delta controls the amount of CP violation in the lepton sector. The identity between the solutions is that the difference in the values of sin⁡δ\sin \delta for the two hierarchies equals twice the value of sin⁡22θ13\sqrt{\sin^2 2\theta_{13}} divided by the {\it critical} value of sin⁡22θ13\sqrt{\sin^2 2\theta_{13}}. We apply this identity to the two proposed long baseline experiments, T2K and NOν\nuA, and we show how it can be used to provide a simple understanding of when and why fake solutions are excluded when two or more experiments are combined. The identity demonstrates the true complimentarity of T2K and NOν\nuA.Comment: 15 pages, Latex, 4 postscript figures. Submitted to New Journal of Physics, ``Focus on Neutrino Physics'' issu

    New interactions: past and future experiments

    Get PDF
    In this talk I will review the present status and future perspectives of some popular extensions of the conventional three-neutrino oscillation scenario, from a purely phenomenological point of view. For concreteness I will focus only on three specific scenarios: non-standard neutrino interactions with matters, models with extra sterile neutrinos, and neutrino decay and decoherence.Comment: LaTeX file using jpconf class, 8 pages, 2 tables. Proceedings of the "XXIII International Conference on Neutrino Physics and Astrophysics" (Neutrino 08), Christchurch, New Zealand, May 25-31, 200
    • …
    corecore