10,647 research outputs found
Corrected sidereal anisotropy for underground moons
Data from underground muon telescopes in New Mexico and Bolivia are analyzed in sidereal time and anti-sidereal time in the rigidity range 20 GV to a few 100's of GV. Using both vertical and north- and south- pointing telescopes in both hemispheres, a latitude range of 70 N to 50 S is covered. It is shown that there is an anti-sidereal variation of the P 1 over 2 type, having opposite phase in the Northern and Southern Hemispheres, and maximum amplitude at mid latitudes. The anti-sidereal data are used to correct the sidereal data, using the Nagashima method (Nagashima, 1984); the resulting corrected sidereal vectors for northern hemisphere telescopes have their sidereal maxima close to 3h sidereal time, in reasonable agreement with sidereal data at higher energies from small air showers. The Nagashima correction also eliminates effects due to the reversal of the Sun's polar magnetic field which show up in the uncorrected sidereal data
Sidereal frequency generator Patent
System generating sidereal frequency signals from signals of standard solar frequency without use of mixing operations or feedback loop
Large-Scale Sidereal Anisotropy of Galactic Cosmic-Ray Intensity Observed by the Tibet Air Shower Array
We present the large-scale sidereal anisotropy ofgalactic cosmic-ray
intensity in the multi-TeV region observed with the Tibet-IIIair shower array
during the period from 1999 through 2003. The sidereal daily variation of
cosmic rays observed in this experiment shows an excess of relative intensity
around hours local sidereal time, as well as a deficit around 12
hours local sidereal time. While the amplitude of the excess is not significant
when averaged over all declinations, the excess in individual declinaton bands
becomes larger and clearer as the viewing direction moves toward the south. The
maximum phase of the excess intensity changes from 7 at the northern
hemisphere to 4 hours at the equatorial region. We also show that both
the amplitude and the phase of the first harmonic vector of the daily variation
are remarkably independent of primary energy in the multi-TeV region. This is
the first result determining the energy and declination dependences of the full
24-hour profiles of the sidereal daily variation in the multi-TeV region with a
single air shower experiment.Comment: 13 pages, 3 figures, 1 table. Accepted for publication in ApJ
Search for Lorentz Invariance and CPT Violation with the MINOS Far Detector
We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be
a consequence of Lorentz and CPT violation as described by the standard-model extension framework. It
also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We
found no evidence for this sidereal signature, and the upper limits placed on the magnitudes of the Lorentz
and CPT violating coefficients describing the theory are an improvement by factors of 20–510 over the
current best limits found by using the MINOS near detector
The Search for Neutrino-Antineutrino Mixing from Lorentz Invariance Violation using Neutrino Interactions in MINOS
We searched for a sidereal modulation in the rate of neutrinos observed by
the MINOS far detector. The detection of these signals could be a signature of
neutrino-antineutrino mixing due to Lorentz and CPT violation as described by
the Standard-Model Extension framework. We found no evidence for these sidereal
signals and we placed limits on the coefficients in this theory describing the
effect.Comment: Presented at the Sixth Meeting on CPT and Lorentz Symmetry,
Bloomington, Indiana, June 17-21, 201
Testing Lorentz and CPT Invariance with MINOS Near Detector Neutrinos
We present an analysis designed to search for Lorentz and CPT violations as
predicted by the SME framework using the charged current neutrino events in the
MINOS near detector. In particular we develop methods to identify periodic
variations in the normalized number of charged current neutrino events as a
function of sidereal phase. To test these methods, we simulated a set of 1,000
experiments without Lorentz and CPT violation signals using the standard MINOS
Monte Carlo. We performed an FFT on each of the simulated experiments to find
the distribution of powers in the sidereal phase diagram without a signal. We
then injected a signal of increasing strength into the sidereal neutrino
oscillation probability until we found a 5 deviation from the mean in
the FFT power spectrum. By this method, we can establish upper limits for the
Lorentz and CPT violating terms in the SME.Comment: 6 pages, 4 figures, CPT'07 Conference proceeding
Tests of Lorentz violation in muon antineutrino to electron antineutrino oscillations
A recently developed Standard-Model Extension (SME) formalism for neutrino
oscillations that includes Lorentz and CPT violation is used to analyze the
sidereal time variation of the neutrino event excess measured by the Liquid
Scintillator Neutrino Detector (LSND) experiment. The LSND experiment,
performed at Los Alamos National Laboratory, observed an excess, consistent
with neutrino oscillations, of in a beam of . It
is determined that the LSND oscillation signal is consistent with no sidereal
variation. However, there are several combinations of SME coefficients that
describe the LSND data; both with and without sidereal variations. The scale of
Lorentz and CPT violation extracted from the LSND data is of order
GeV for the SME coefficients and . This solution for
Lorentz and CPT violating neutrino oscillations may be tested by other short
baseline neutrino oscillation experiments, such as the MiniBooNE experiment.Comment: 10 pages, 10 figures, 2 tables, uses revtex4 replaced with version to
be published in Physical Review D, 11 pages, 11 figures, 2 tables, uses
revtex
Sidereal anisotropy of cosmic rays
The data of the ionization chamber in Yakutsk for 1954 to 1984 are analyzed. A false sidereal variation caused by the second spherical harmonic in cosmic ray distribution was found and it has the amplitude 0.020 plus or minus 0.002%. The sidereal anisotropy with a very small amplitude (not more than 0.005%) was observed to exist
The Search for Neutrino-Antineutrino Mixing Resulting from Lorentz Invariance Violation using neutrino interactions in MINOS
We searched for a sidereal modulation in the rate of neutrinos produced by
the NuMI beam and observed by the MINOS far detector. The detection of such
harmonic signals could be a signature of neutrino-antineutrino mixing due to
Lorentz and CPT violation as described by the Standard Model Extension
framework. We found no evidence for these sidereal signals and we placed limits
on the coefficients in this theory describing the effect. This is the first
report of limits on these neutrino-antineutrino mixing coefficients.Comment: 11 pages, 2 figures, 3 table
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