772 research outputs found
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
Probing Relativity using Space-Based Experiments
An overview of space tests searching for small deviations from special
relativity arising at the Planck scale is given. Potential high-sensitivity
space-based experiments include ones with atomic clocks, masers, and
electromagnetic cavities. We show that a significant portion of the coefficient
space in the Standard-Model Extension, a framework that covers the full
spectrum of possible effects, can be accessed using space tests. Some remarks
on Lorentz violation in the gravitational sector are also given.Comment: 12 pages, invited talk at International Workshop, From Quantum to
Cosmos, Warrenton, VA, USA, May 22-24, 200
Systemic distribution of different low pathogenic avian influenza (LPAI) viruses in chicken
<p>Abstract</p> <p>Background</p> <p>Since we were able to isolate viable virus from brain and lung of H7N1 low pathogenic avian influenza virus (LPAIV) infected chickens, we here examined the distribution of different LPAIV strains in chickens by measuring the viral AI RNA load in multiple organs. Subtypes of H5 (H5N1, H5N2), H7 (H7N1, H7N7) and H9 (H9N2), of chicken (H5N2, H7N1, H7N7, H9N2), or mallard (H5N1) origin were tested. The actual presence of viable virus was evaluated with virus isolation in organs of H7N7 inoculated chickens.</p> <p>Findings</p> <p>Viral RNA was found by PCR in lung, brain, intestine, peripheral blood mononuclear cells, heart, liver, kidney and spleen from chickens infected with chicken isolated LPAIV H5N2, H7N1, H7N7 or H9N2. H7N7 virus could be isolated from lung, ileum, heart, liver, kidney and spleen, but not from brain, which was in agreement with the data from the PCR. Infection with mallard isolated H5N1 LPAIV resulted in viral RNA detection in lung and peripheral blood mononuclear cells only.</p> <p>Conclusion</p> <p>We speculate that chicken isolated LPAI viruses are spreading systemically in chicken, independently of the strain.</p
Bounds on Lorentz and CPT Violation from the Earth-Ionosphere Cavity
Electromagnetic resonant cavities form the basis of many tests of Lorentz
invariance involving photons. The effects of some forms of Lorentz violation
scale with cavity size. We investigate possible signals of violations in the
naturally occurring resonances formed in the Earth-ionosphere cavity.
Comparison with observed resonances places the first terrestrial constraints on
coefficients associated with dimension-three Lorentz-violating operators at the
level of 10^{-20} GeV.Comment: 8 pages REVTe
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