370 research outputs found
CP, T and CPT violation in future long baseline experiments
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 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
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. sensitivity down to and a
sensitivity comparable to a Neutrino Factory, for ,
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 -beam
The precision measurement and discovery potential of a neutrino factory based
on a storage ring of boosted radioactive ions (-beam) is re-examined. In
contrast with past designs, which assume ion factors of and
baselines of L=130 km, we emphasize the advantages of boosting the ions to
higher and increasing the baseline proportionally. In particular, we
consider a medium- scenario (, L=730 km) and a
high- scenario (, 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
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 -beam at the CERN-SPS
A -beam with maximum (for \helio ions) or
(for \neon) could be achieved at the CERN-SPS. We study the sensitivity to
and of such a beam as function of , 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 , and also
with a higher option that requires a more powerful
accelerator. Although higher is better, loss of sensitivity to and is most pronounced for below 100.Comment: 22 page
Physics Potential of Very Intense Conventional Neutrino Beams
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
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 and the
CP-phase . 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
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 is \gsim
5\times10^{-5} eV. 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
down to 0.03 for eV. It
would be highly advantageous to have a 10% determination of before the beam energies and baselines are finalized, although if
is not that well known, the neutrino energies and
baselines can be chosen to give fairly good sensitivity for a range of .Comment: 18 pages, 6 PS figures, added references and revised discussio
disappearance at the SPL, T2K-I, NOA and the Neutrino Factory
We study the measurement of the atmospheric neutrino oscillation parameters,
and , at the disappearance channel at
three conventional beam facilities, the SPL, T2K-phase I and NOA. These
two parameters have been shown to be of crucial importance in the measurement
of two of the unknowns of the PMNS mixing matrix, and the
leptonic CP-violating phase . In our analyis, the effect of the two
discrete ambiguities, and , is explicitly taken into account. We analyse also the
disappearance channel at the Neutrino Factory, and combine it with the
``golden'' and ``silver'' appearance
channels to study its impact on the measurement of and .
Eventually, we present the sensitivity of the four facilities to different
observables: , , maximal , the sign of the
atmospheric mass difference, , and the -octant,
.Comment: 40 pages using epsfig; bibliography modifie
Reconstructing the calibrated strain signal in the Advanced LIGO detectors
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
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