370 research outputs found

    CP, T and CPT violation in future long baseline experiments

    Get PDF
    I give a short overview about the possibilities and problems related to the measurement of CP violation in long baseline experiments. Special attention is paid to the issue of degeneracies and a method for their resolution is quantitatively discussed. The CP violation reach for different experiments is compared in dependence of sin22θ13\sin^22\theta_{13} and \dm{21}. Furthermore a short comment about the possible effects of matter induced T violation is made. Finally the limits on CPT violation obtainable at a neutrino factory are shown.Comment: Talk presented at NUFACT02, London, 1-6 July, 2002. 3 pages, 2 figure

    Physics Potential of the SPL Super Beam

    Get PDF
    Performances of a neutrino beam generated by the CERN SPL proton driver are computed considering a 440 kton water Cerenkov detector at 130 km from the target. θ13\theta_{13} sensitivity down to 1.21.2^\circ and a δ\delta sensitivity comparable to a Neutrino Factory, for θ133\theta_{13} \geq 3^\circ, are within the reach of such a project.Comment: Invited talk at the Nufact02 Workshop, Imperial College of Science, Technology and Medicine, London, July 200

    Neutrino oscillation physics with a higher γ\gamma β\beta-beam

    Full text link
    The precision measurement and discovery potential of a neutrino factory based on a storage ring of boosted radioactive ions (β\beta-beam) is re-examined. In contrast with past designs, which assume ion γ\gamma factors of 100\sim 100 and baselines of L=130 km, we emphasize the advantages of boosting the ions to higher γ\gamma and increasing the baseline proportionally. In particular, we consider a medium-γ\gamma scenario (γ500\gamma \sim 500, L=730 km) and a high-γ\gamma scenario (γ2000\gamma \sim 2000, L = 3000 km).The increase in statistics, which grow linearly with the average beam energy, the ability to exploit the energy dependence of the signal and the sizable matter effects at this longer baseline all increase the discovery potential of such a machine very significantly.Comment: An error corrected, conclusions unchanged. Revised version to appear in Nuclear Physics

    Médecins Blancs et Sorciers en Pays Colonisé: Politiques de santé, modes d’influence et oppositions

    Get PDF
    L’article  traite  de  la  politique  de  santé  engagée  à  Madagascar  en  période  coloniale  dont  l’objectif principal était d’améliorer l’état sanitaire du pays afin de faire progresser la situation démographique. Les modes d’influence du pouvoir étaient nombreux pour gagner la confiance des Malgaches et, ainsi, imposer les normes occidentales dans le domaine de la santé.Les  agents  de  santé,  médecins  militaires  et  civils,  rencontraient  des  difficultés  à  expérimenter  de nouveaux  procédés  thérapeutiques  et  répandre une  vision  hygiéniste  occidentale.  Ce  qui  freinait l’étendue et l’évolution de l’Assistance médicale indigène était en partie dû à l’attitude réfractaire des populations locales. Parmi les modes d’influence convoqués pour amener les indigènes à consulter le médecin  colonial  ou  le  médecin  blanc,  puis  le  médecin  dit  de  brousse,  qui  permettaient  de  réduire quelque peu les rapports de force, notons l’importance donnée à l’amélioration technique des procédés thérapeutiques et des infrastructures mais aussi à la transmission de l’information médicale.Cependant, les médecins coloniaux étaient aussi confrontés à l’autorité et à l’influence des thérapeutes indigènes  ou  devins-guérisseurs  (ombiasy)  qui,  de  tradition,  étaient  les  principaux  soignants.  Ces personnages qui avaient la connaissance de la pharmacopée et des techniques thérapeutiques magico- religieuses - comme la lecture divinatoire et l’astrologie - étaient perçus par le pouvoir colonial et ses agents  médicaux  comme  dangereux  du  fait  de  leur  autorité  religieuse,  parfois  mise  au  service d’actions politiques

    Optimal β\beta-beam at the CERN-SPS

    Full text link
    A β\beta-beam with maximum γ=150\gamma=150 (for \helio ions) or γ=250\gamma=250 (for \neon) could be achieved at the CERN-SPS. We study the sensitivity to θ13\theta_{13} and δ\delta of such a beam as function of γ\gamma, optimizing with the baseline constrained to CERN-Frejus (130 km), and also with simultaneous variation of the baseline. These results are compared to the {\it standard} scenario previously considered, with lower γ=60/100\gamma=60/100, and also with a higher γ350\gamma\sim 350 option that requires a more powerful accelerator. Although higher γ\gamma is better, loss of sensitivity to θ13\theta _{13} and δ\delta is most pronounced for γ\gamma below 100.Comment: 22 page

    Physics Potential of Very Intense Conventional Neutrino Beams

    Get PDF
    The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters and measure or severely constrain the parameter connecting the atmospheric and solar realms. It is also shown that a very large water detector could eventually observe leptonic CP violation. The reach of such an experiment to the neutrino mixing parameters would lie in-between the next generation of neutrino experiments (MINOS, OPERA, etc) and a future neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice, March, 200

    Unveiling Neutrino Mixing and Leptonic CP Violation

    Get PDF
    We review the present understanding of neutrino masses and mixings, discussing what are the unknowns in the three family oscillation scenario. Despite the anticipated success coming from the planned long baseline neutrino experiments in unraveling the leptonic mixing sector, there are two important unknowns which may remain obscure: the mixing angle θ13\theta_{13} and the CP-phase δ\delta. The measurement of these two parameters has led us to consider the combination of superbeams and neutrino factories as the key to unveil the neutrino oscillation picture.Comment: Invited brief review, 18 pages, 6 figure

    How two neutrino superbeam experiments do better than one

    Get PDF
    We examine the use of two superbeam neutrino oscillation experiments with baselines \lsim 1000 km to resolve parameter degeneracies inherent in the three-neutrino analysis of such experiments. We find that with appropriate choices of neutrino energies and baselines two experiments with different baselines can provide a much better determination of the neutrino mass ordering than a single experiment alone. Two baselines are especially beneficial when the mass scale for solar neutrino oscillations δmsol2\delta m^2_{\rm sol} is \gsim 5\times10^{-5} eV2^2. We also examine CP violation sensitivity and the resolution of other parameter degeneracies. We find that the combined data of superbeam experiments with baselines of 295 and 900 km can provide sensitivity to both the neutrino mass ordering and CP violation for sin22θ13\sin^22\theta_{13} down to 0.03 for δmatm23×103|\delta m^2_{\rm atm}| \simeq 3\times10^{-3} eV2^2. It would be highly advantageous to have a 10% determination of δmatm2|\delta m^2_{\rm atm}| before the beam energies and baselines are finalized, although if δmatm2|\delta m^2_{\rm atm}| is not that well known, the neutrino energies and baselines can be chosen to give fairly good sensitivity for a range of δmatm2|\delta m^2_{\rm atm}|.Comment: 18 pages, 6 PS figures, added references and revised discussio

    νμ\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(tan2θ23){\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'' νeνμ\nu_e \to \nu_\mu and ``silver'' νeντ\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

    Reconstructing the calibrated strain signal in the Advanced LIGO detectors

    Get PDF
    Advanced LIGO's raw detector output needs to be calibrated to compute dimensionless strain h(t). Calibrated strain data is produced in the time domain using both a low-latency, online procedure and a high-latency, offline procedure. The low-latency h(t) data stream is produced in two stages, the first of which is performed on the same computers that operate the detector's feedback control system. This stage, referred to as the front-end calibration, uses infinite impulse response (IIR) filtering and performs all operations at a 16384 Hz digital sampling rate. Due to several limitations, this procedure currently introduces certain systematic errors in the calibrated strain data, motivating the second stage of the low-latency procedure, known as the low-latency gstlal calibration pipeline. The gstlal calibration pipeline uses finite impulse response (FIR) filtering to apply corrections to the output of the front-end calibration. It applies time-dependent correction factors to the sensing and actuation components of the calibrated strain to reduce systematic errors. The gstlal calibration pipeline is also used in high latency to recalibrate the data, which is necessary due mainly to online dropouts in the calibrated data and identified improvements to the calibration models or filters.Comment: 20 pages including appendices and bibliography. 11 Figures. 3 Table
    corecore