5,036 research outputs found
Four-neutrino mixing solutions of the atmospheric neutrino anomaly
Solutions to the atmospheric neutrino anomaly which smoothly interpolate
between nu_mu -> nu_tau and nu_mu -> nu_s oscillations are studied. It is shown
that, although the Super-Kamiokande data disfavor the pure nu_mu -> nu_s
channel, one cannot exclude sizable amplitude for the nu_mu -> nu_s channel in
addition to nu_mu -> nu_tau oscillations.Comment: Talk given at Europhysics Neutrino Oscillation Workshop (NOW2000),
Conca Specchiulla, Otranto, Lecce, Ita, 9-16 Sep 200
Breaking Eight-fold Degeneracies in Neutrino CP Violation, Mixing, and Mass Hierarchy
We identify three independent two-fold parameter degeneracies (\delta,
\theta_{13}), sgn(\delta m^2_{31}) and (\theta_{23}, \pi/2-\theta_{23})
inherent in the usual three-neutrino analysis of long-baseline neutrino
experiments, which can lead to as much as an eight-fold degeneracy in the
determination of the oscillation parameters. We discuss the implications these
degeneracies have for detecting CP violation and present criteria for breaking
them. A superbeam facility with a baseline at least as long as the distance
between Fermilab and Homestake (1290 km) and a narrow band beam with energy
tuned so that the measurements are performed at the first oscillation peak can
resolve all the ambiguities other than the (\theta_{23}, \pi/2-\theta_{23})
ambiguity (which can be resolved at a neutrino factory) and a residual (\delta,
\pi-\delta) ambiguity. However, whether or not CP violation occurs in the
neutrino sector can be ascertained independently of the latter two ambiguities.
The (\delta,\pi-\delta) ambiguity can be eliminated by performing a second
measurement to which only the \cos\delta terms contribute. The hierarchy of
mass eigenstates can be determined at other oscillation peaks only in the most
optimistic conditions, making it necessary to use the first oscillation
maximum. We show that the degeneracies may severely compromise the ability of
the proposed SuperJHF-HyperKamiokande experiment to establish CP violation. In
our calculations we use approximate analytic expressions for oscillation
probabilitites that agree with numerical solutions with a realistic Earth
density profile.Comment: Revtex (singlespaced), 35 pages, 15 postscript figures, uses
psfig.st
Matter profile effect in neutrino factory
We point out that the matter profile effect --- the effect of matter density
fluctuation on the baseline --- is very important to estimate the parameters in
a neutrino factory with a very long baseline. To make it clear, we propose the
method of the Fourier series expansion of the matter profile. By using this
method, we can take account of both the matter profile effect and its
ambiguity. For very long baseline experiment, such as L=7332km, in the analysis
of the oscillation phenomena we need to introduce a new parameter ---
the Fourier coefficient of the matter profile --- as a theoretical parameter to
deal with the matter profile effects.Comment: 21 pages, 15 figure
The MONOLITH project
MONOLITH is a proposed massive (34 kt) magnetized tracking calorimeter at the
Gran Sasso laboratory in Italy, optimized for the detection of atmospheric muon
neutrinos. The main goal is to establish (or reject) the neutrino oscillation
hypothesis through an explicit observation of the full first oscillation swing.
The Delta m^2 sensitivity range for this measurement comfortably covers the
complete Super-Kamiokande allowed region. Other measurements include studies of
matter effects and the NC/CC and anti-nu/nu ratio, the study of cosmic ray
muons in the multi-TeV range, and auxiliary measurements from the CERN to Gran
Sasso neutrino beam. Depending on approval, data taking with part of the
detector could start in 2004. The detector and its performance are described,
and its potential later use as a neutrino factory detector is addressed.Comment: 6 pages. Contribution to NUFACT'00 neutrino factory workshop,
Monterey, CA, USA, May 22-26, 200
Theory for computing the field scattered from a smooth inflected surface
A theory is described for computing the reflected or scattered field from a smooth body with inflection points. These inflections occur in certain directions at each surface point for which the total (Gaussian) curvature is zero or negative. For surface illumination in one of these critical directions, the usual reflection formulas obtained by the high-frequency approximation are inapplicable, and a shadow zone exists in the reflected field. Scattering into the shadow zone is treated, as well as specular reflection. This theory should have a variety of applications such as for certain optics problems, computer graphics modeling of three-dimensional shapes, and the design and analysis of specialized microwave reflector antennas
Buoyant Venus Station feasibility study. Volume III - Instrumentation study Final report
Scientific instrumentation for inflatable buoyant Venus statio
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