1,031 research outputs found
Measurement of the 0.511 MeV gamma ray line from the Galactic Center
The detection of the 0.511 MeV electron positron annihilation line coming from the Galactic Center to provide the means to estimate the rate of positron production and to test some theoretical sources of positrons is addressed. The results of the measurements of the 0.511 MeV line flux made with a gamma ray experiment on board a stratospheric balloon are presented. The detector field of view looked at the galactic longitude range -31 deg l(II) +41 deg. The observed flux is 0.0067 (+ or - 0.0005) photons 1/cm(2)5 which is in very good agreement with the expected flux when assuming that the Galactic Center is a line source emitting uniformly
Effects of Lorentz violation in superconductivity
This paper presents the effects of Lorentz violation in superconductivity.
Constructing a Lorentz-Violating Ginzburg-Landau theory of superconductivity we
discuss the influence of the Lorentz-Violating tensors and
in the London's depth penetration, in the coherence length and
critical magnetic field.Comment: 5 pages, 1 figure, two columns. Matches version to be published at
EP
Heterotic Compactification, An Algorithmic Approach
We approach string phenomenology from the perspective of computational
algebraic geometry, by providing new and efficient techniques for proving
stability and calculating particle spectra in heterotic compactifications. This
is done in the context of complete intersection Calabi-Yau manifolds in a
single projective space where we classify positive monad bundles. Using a
combination of analytic methods and computer algebra we prove stability for all
such bundles and compute the complete particle spectrum, including gauge
singlets. In particular, we find that the number of anti-generations vanishes
for all our bundles and that the spectrum is manifestly moduli-dependent.Comment: 36 pages, Late
Métodos para a determinação de multiresíduos de agrotóxicos em produtos agrícolas.
bitstream/CNPMA/7716/1/documentos_71.pd
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