1997/07/09 by J. Bijnens, Johan Bijnens, G. Colangelo +3 · 5 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/s0550-3213(97)00621-4
published as Nucl.Phys. B508 (1997) 263-310; Erratum-ibid. B517 (1998) 639 · LaTeX, uses epsf.sty, 10 figures, 52 pages
arxiv created 1997/07/09 · openalex publication_date 1997/12/22 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present technical details of the evaluation of the elastic pi-pi scattering amplitude to two loops in chiral perturbation theory. In particular, we elaborate on the renormalization procedure at the two-loop order and on the evaluation of the relevant Feynman diagrams that can all be expressed in terms of elementary functions. For the sake of clarity, we discuss these matters both in the N-component ϕ4 theory (in its symmetric phase) and in chiral perturbation theory. Estimates for the relevant low-energy constants of O(p6) are presented. Threshold parameters and phase shifts are then calculated for two sets of O(p4) coupling constants and compared with experiment. We comment on the extraction of threshold parameters from phase shift data.