1999/12/12 by Ulf-G. Meißner, U MeiÃner, J. A. Oller · 4 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Nuclear physics research studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-th
paper · pdf · doi:10.1016/s0375-9474(00)00150-0
published as Nucl.Phys. A673 (2000) 311-334 · 23 pp, LaTeX2e, 10 figs
arxiv created 1999/12/12 · openalex publication_date 2000/06/19 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We develop a novel approach to chiral meson-baryon dynamics incorporating unitarity constraints and explicit resonance fields. It is based on the most general structure of any pion-nucleon partial wave amplitude neglecting the unphysical cuts as derived from the N/D method. This amplitude is then matched to the one-loop heavy baryon chiral perturbation theory result at third order and to tree level exchanges of baryon- and meson states in the s,t and u channels. This generates the left-hand cuts. The unitarization procedure does not involve form factors or regulator functions. The resonance parameters are determined from fits to the S- and P-wave pion-nucleon partial wave amplitudes for energies up to 1.3 GeV. In particular, the Δ(1232) is accurately reproduced whereas scalar and vector meson couplings are less precisely pinned down. We also obtain a satisfactory description of the πN threshold parameters. Further extensions of this method to coupled channels and the three-flavor case are briefly discussed.