2005/06/08 by Véronique Bernard, V. Bernard, Bastian Kubis +3 · 1 citation
Physics and Astronomy · #Amplitude #Baryon #Chiral perturbation theory #Covariant transformation #Dispersion relation #High-Energy Particle Collisions Research #Nucleon #Particle physics theoretical and experimental studies #Perturbation theory (quantum mechanics) #Pion #Quantum Chromodynamics and Particle Interactions #Sum rule in quantum mechanics #nucl-th
paper · pdf · doi:10.1140/epja/i2005-10144-9
published as Eur.Phys.J. A25 (2005) 419-425 · 7 pages, 2 figs
arxiv created 2005/06/08 · openalex publication_date 2005/09/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We analyze the Fubini-Furlan-Rosetti sum rule in the framework of covariant baryon chiral perturbation theory to leading one-loop accuracy and including next-to-leading order polynomial contributions. We discuss the relation between the subtraction constants in the invariant amplitudes and certain low-energy constants employed in earlier chiral perturbation theory studies of threshold neutral pion photoproduction off nucleons. In particular, we consider the corrections to the sum rule due to the finite pion mass and show that below the threshold they agree well with determinations based on fixed-t dispersion relations. We also discuss the energy dependence of the electric dipole amplitude E0+.