Data acquired with a Compton gamma-camera are empirical measures of the Compton transform. This integral transform consists to calculate integrals of the intensity distribution of the source on conical surfaces. In this work, we analyze the direct problem and we show that under the non-realistic hypothesis of an infinite extent detector it is possible to isolate classes of Compton projections t...

Aims. We wish to provide simple and accurate analytic approximations for the low frequency double Compton (DC) emission coefficient , which are applicable in a broad range of physical situations up to mildly relativistic temperatures and may be useful for checking under which circumstances the double Compton process is important. Methods. We perform series expansions of the DC emission integral...

We analyze the correlation eeects in two electron atoms and ions which can be probed in double ionization with high energy photons. We consider total cross sections and diierential cross sections for double ionization by pho-toabsorption and Compton scattering and discuss the shake and non{shake mechanisms which may contribute to these observables. The total cross section for photoabsorption (a...

We calculate spin, charge, and azimuthal asymmetries in deeply virtual Compton scattering at leading twist-two level. The measurement of these asymmetries gives access to the imaginary and real part of all deeply virtual Compton scattering amplitudes. We note that a consistent description of this process requires taking into account twist-three contributions and we give then a model dependent e...

The Compton effect is commonly cited as a demonstration of the particle feature of light. In this investigation, we present an alternative interpretation of the Compton effect based on the postulates of de Broglie and on the wave scattering from a spaceand timevarying medium, without explicit resort to the conservation of energy and momentum. PACS numbers: 13.60.Fz, 03.65.Ta, 03.75.-b

A modification of the popular unification model for Seyfert galaxies is proposed, which takes into account recent observational findings on the statistical properties of both type 1 and type 2 Seyferts. In the proposed scenario, Compton–thick Seyfert 2 galaxies are those sources observed through compact, thick matter (the ‘torus’), while Compton–thin/ intermediate Seyfert galaxies are obscured ...

A measurement of parity-violating spin-dependent γ−→p Compton scattering will provide a theoretically clean determination of the parity-violating pionnucleon coupling constant h (1) πNN . We calculate the leading parity-violating amplitude arising from one-loop pion graphs in chiral perturbation theory. An asymmetry of ∼ 5×10−8 is estimated for Compton scattering of 100 MeV photons.