Predictions of chiral perturbation theory for Compton scattering off protons
Abstract
Description
We compute the Compton scattering off the nucleons in the framework of manifestly covariant baryon chiral perturbation theory (B$χ$PT). The results for observables differ substantially from the corresponding calculations in heavy-baryon chiral perturbation theory (HB$χ$PT), most appreciably in the forward kinematics. We verify that the covariant $p^3$ result fulfills the forward-Compton-scattering sum rules. We also explore the effect of the $Δ$(1232) resonance. We find that the substantial effect of the $Δ$-excitation on the nucleon polarizabilities can naturally be accommodated in the manifestly covariant calculation.
7 pages, 4 figures, to appear in in the proceedings of the International Workshop on Effective Field Theories: from the Pion to the Upsilon. EFT09, Valencia, 1-6 Feb. 2009
7 pages, 4 figures, to appear in in the proceedings of the International Workshop on Effective Field Theories: from the Pion to the Upsilon. EFT09, Valencia, 1-6 Feb. 2009