Pion Compton scattering and bremsstrahlung

Deuteron Compton Scattering below Pion Photoproduction Threshold

Deuteron Compton scattering below pion photoproduction threshold is considered in the framework of the non-relativistic diagrammatic approach with the Bonn OBE potential. The complete gauge-invariant set of diagrams is taken into account which includes resonance diagrams without and with rescattering and diagrams with oneand two-body seagulls. The obtained results are compared with predictions ...

Compton scattering by a pion and off-shell effects.

We consider Compton scattering by a pion in the framework of chiral perturbation theory. We investigate off–shell effects in the s– and u–channel pole diagrams. For that purpose we perform a field transformation which, in comparison with the standard Gasser and Leutwyler Lagrangian, generates additional terms at order p4 proportional to the lowest–order equation of motion. As a result of the eq...

Compton scattering from a pion and off – shell effects ∗

We discuss the most general form of the electromagnetic vertex of an off–shell pion. The framework of chiral perturbation theory is used to illustrate the representation dependence of the electromagnetic three–point Green's function. For that purpose we discuss the concept of field transformations which, in comparison with the standard Gasser and Leutwyler Lagrangian, generate equivalent Lagran...

Compton scattering from the deuteron below pion-production threshold

Applicability of Perturbative QCD to Pion Virtual Compton Scattering

We study explicitly the applicability of perturbative QCD (pQCD) to the pion virtual Compton scattering. It is found that there are central-region singularities introduced by the QCD running coupling constant, in addition to the end-point singularities generally existed in other exclusive processes such as the pion form factor. We introduce a simple technique to evaluate the contributions from ...