0000000000914804

AUTHOR

M. Sikora

showing 3 related works from this author

Evidence for Strange-Quark Contributions to the Nucleon’s Form Factors atQ2=0.108   (GeV/c)2

2005

We report on a measurement of the parity violating asymmetry in the elastic scattering of polarized electrons off unpolarized protons with the A4 apparatus at MAMI in Mainz at a four momentum transfer value of ${Q}^{2}=0.108\text{ }(\mathrm{GeV}/c{)}^{2}$ and at a forward electron scattering angle of $30\ifmmode^\circ\else\textdegree\fi{}l{\ensuremath{\theta}}_{e}l40\ifmmode^\circ\else\textdegree\fi{}$. The measured asymmetry is ${A}_{LR}(\stackrel{\ensuremath{\rightarrow}}{e}p)=[\ensuremath{-}1.36\ifmmode\pm\else\textpm\fi{}0.29(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.13(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}$. The expectation from the standard model as…

PhysicsStrange quarkParticle physics010308 nuclear & particles physicsHadronGeneral Physics and AstronomyElementary particleFermionStrangeness01 natural sciencesBaryon0103 physical sciences010306 general physicsNucleonLeptonPhysical Review Letters
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The NHXM observatory

2011

Exploration of the X-ray sky has established X-ray astronomy as a fundamental astrophysical discipline. While our knowledge of the sky below 10 keV has increased dramatically (∼8 orders of magnitude) by use of grazing incidence optics, we still await a similar improvement above 10 keV, where to date only collimated instruments have been used. Also ripe for exploration is the field of X-ray polarimetry, an unused fundamental tool to understand the physics and morphology of X-ray sources. Here we present a novel mission, the New Hard X-ray Mission (NHXM) that brings together for the first time simultaneous high-sensitivity, hard-X-ray imaging, broadband spectroscopy and polarimetry. NHXM will…

Black-holesAcceleration mechanismCosmic Visionmedia_common.quotation_subjectPolarimetry7. Clean energy01 natural sciencesMissionsCosmologyPhysical cosmologyNon-thermal emissionAcceleration mechanism; Accretion physics; Black-holes; Compact objects; Cosmology; Missions; Non-thermal emission; X-ray imaging; X-ray polarimetry; Astronomy and Astrophysics; Space and Planetary ScienceObservatory0103 physical sciencesBroadbandX-ray polarimetry010303 astronomy & astrophysicsCompact objectsmedia_commonPhysics010308 nuclear & particles physicsX-ray imagingVegaAstronomyAstronomy and AstrophysicsAccretion physicsCosmologySkySpace and Planetary ScienceExperimental Astronomy
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Bending relativistic jets in AGNs

1997

We present simulations of relativistic jets propagating in a nonuniform medium. Specifically, we study the bending of jets propagating obliquely to the vector of the density-gradient. Our results are applied to the NGC 4258, where such a medium is assumed to be provided by the atmosphere of the sub-parsec accretion disk tilted with respect to the original direction of the jet propagation. As a result, the jet is bent on a scale comparable to the density scaleheight of the disk atmosphere. The magnitude of the bending effect is found to be largest for light jets with low Lorentz factors. The predicted direction of bending is consistent with the observations.

Astrophysics::High Energy Astrophysical PhenomenaAstrophysics (astro-ph)FOS: Physical sciencesAstrophysics::Earth and Planetary AstrophysicsAstrophysicsAstrophysics::Galaxy Astrophysics
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