2000/06/27 by Nadia Fettes, Ulf-G. Meißner · 1 citation
Physics and Astronomy · #Chiral perturbation theory #Effective field theory #Fermion #Field theory (psychology) #High-Energy Particle Collisions Research #Lagrangian #Nuclear physics research studies #Nucleon #Pion #Quantum Chromodynamics and Particle Interactions #Scattering #Scattering theory #Sigma #hep-ph #nucl-th
paper · pdf · doi:10.1016/s0375-9474(00)00368-7
published as Nucl.Phys. A679 (2001) 629-670 · 44 pp, LaTeX2e, uses epsf, 6 figs
arxiv created 2000/06/27 · openalex publication_date 2001/01/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We analyze elastic-pion nucleon scattering to third order in the so-called small scale expansion. It is based on an effective Lagrangian including pions, nucleons and deltas as active degrees of freedom and counting external momenta, the pion mass and the nucleon-delta mass splitting as small parameters. The fermion fields are considered as very heavy. We present results for phase shifts, threshold parameters and the sigma term. We discuss the convergence of the approach. A detailed comparison with results obtained in heavy baryon chiral perturbation theory to third and fourth order is also given.