6533b7dafe1ef96bd126e3ba

RESEARCH PRODUCT

Virtual Compton scattering off the nucleon in chiral perturbation theory

Stefan SchererG. KnöchleinBarry R. HolsteinThomas R. Hemmert

subject

PhysicsNuclear and High Energy PhysicsChiral perturbation theoryNuclear TheoryCrossingCompton scatteringFOS: Physical sciencesNuclear Theory (nucl-th)Scattering amplitudeHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)AmplitudeQuantum electrodynamicsGauge theoryNucleonMultipole expansion

description

We investigate the spin-independent part of the virtual Compton scattering (VCS) amplitude off the nucleon within the framework of chiral perturbation theory. We perform a consistent calculation to third order in external momenta according to Weinberg's power counting. With this calculation we can determine the second- and fourth-order structure-dependent coefficients of the general low-energy expansion of the spin-averaged VCS amplitude based on gauge invariance, crossing symmetry and the discrete symmetries. We discuss the kinematical regime to which our calculation can be applied and compare our expansion with the multipole expansion by Guichon, Liu and Thomas. We establish the connection of our calculation with the generalized polarizabilities of the nucleon where it is possible.

https://doi.org/10.1103/physrevd.55.2630