946 research outputs found
Status of Salerno Laboratory (Measurements in Nuclear Emulsion)
A report on the analysis work in the Salerno Emulsion Laboratory is
presented. It is related to the search for nu_mu->nu_tau oscillations in CHORUS
experiment, the calibrations in the WANF (West Area Neutrino Facility) at Cern
and tests and preparation for new experiments.Comment: Proc. The First International Workshop of Nuclear Emulsion Techniques
(12-24 June 1998, Nagoya, Japan), 15 pages, 11 figure
Efficient Resolution of Anisotropic Structures
We highlight some recent new delevelopments concerning the sparse
representation of possibly high-dimensional functions exhibiting strong
anisotropic features and low regularity in isotropic Sobolev or Besov scales.
Specifically, we focus on the solution of transport equations which exhibit
propagation of singularities where, additionally, high-dimensionality enters
when the convection field, and hence the solutions, depend on parameters
varying over some compact set. Important constituents of our approach are
directionally adaptive discretization concepts motivated by compactly supported
shearlet systems, and well-conditioned stable variational formulations that
support trial spaces with anisotropic refinements with arbitrary
directionalities. We prove that they provide tight error-residual relations
which are used to contrive rigorously founded adaptive refinement schemes which
converge in . Moreover, in the context of parameter dependent problems we
discuss two approaches serving different purposes and working under different
regularity assumptions. For frequent query problems, making essential use of
the novel well-conditioned variational formulations, a new Reduced Basis Method
is outlined which exhibits a certain rate-optimal performance for indefinite,
unsymmetric or singularly perturbed problems. For the radiative transfer
problem with scattering a sparse tensor method is presented which mitigates or
even overcomes the curse of dimensionality under suitable (so far still
isotropic) regularity assumptions. Numerical examples for both methods
illustrate the theoretical findings
Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS
Tensions in several phenomenological models grew with experimental results on
neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent,
carefully recomputed, antineutrino fluxes from nuclear reactors. At a
refurbished SBL CERN-PS facility an experiment aimed to address the open issues
has been proposed [1], based on the technology of imaging in ultra-pure
cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of
the physics case was performed. We tackled specific physics models and we
optimized the neutrino beam through a full simulation. Experimental aspects not
fully covered by the LAr detection, i.e. the measurements of the lepton charge
on event-by-event basis and their energy over a wide range, were also
investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino
interactions play an important role in disentangling different phenomenological
scenarios provided their charge state is determined. Also, the study of muon
appearance/disappearance can benefit of the large statistics of CC muon events
from the primary neutrino beam. Results of our study are reported in detail in
this proposal. We aim to design, construct and install two Spectrometers at
"NEAR" and "FAR" sites of the SBL CERN-PS, compatible with the already proposed
LAr detectors. Profiting of the large mass of the two Spectrometers their
stand-alone performances have also been exploited.Comment: 70 pages, 38 figures. Proposal submitted to SPS-C, CER
Search for spontaneous muon emission from lead nuclei
We describe a possible search for muonic radioactivity from lead nuclei using
the base elements ("bricks" composed by lead and nuclear emulsion sheets) of
the long-baseline OPERA neutrino experiment. We present the results of a Monte
Carlo simulation concerning the expected event topologies and estimates of the
background events. Using few bricks, we could reach a good sensitivity level.Comment: 12 pages, 4 figure
Electron/pion separation with an Emulsion Cloud Chamber by using a Neural Network
We have studied the performance of a new algorithm for electron/pion
separation in an Emulsion Cloud Chamber (ECC) made of lead and nuclear emulsion
films. The software for separation consists of two parts: a shower
reconstruction algorithm and a Neural Network that assigns to each
reconstructed shower the probability to be an electron or a pion. The
performance has been studied for the ECC of the OPERA experiment [1].
The separation algorithm has been optimized by using a detailed Monte
Carlo simulation of the ECC and tested on real data taken at CERN (pion beams)
and at DESY (electron beams). The algorithm allows to achieve a 90% electron
identification efficiency with a pion misidentification smaller than 1% for
energies higher than 2 GeV
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