2006/08/31 by M. A. Belushkin, M.A. Belushkin, H.‐W. Hammer +3 · 4 citations
Physics and Astronomy · #Charge radius #Coupling (piping) #Coupling constant #Dispersion relation #High-Energy Particle Collisions Research #Mathematical physics #Meson #Momentum (technical analysis) #Nucleon #Omega #Particle physics #Particle physics theoretical and experimental studies #Perturbative QCD #Physics #Proton #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quantum mechanics #RADIUS #Scattering #Sign (mathematics) #Tensor (intrinsic definition) #Unitarity #hep-ex #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevc.75.035202
published as Phys.Rev.C75:035202,2007 · 24 pages, 9 figures
arxiv created 2006/08/31 · openalex publication_date 2007/03/06 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Dispersion relations provide a powerful tool to analyze the electromagnetic form factors of the nucleon for all momentum transfers. Constraints from meson-nucleon scattering data, unitarity, and perturbative quantum chromodynamics (QCD) can be included in a straightforward way. In particular, we include the 2\ensuremathπ,\ensuremathρ\ensuremathπ, and KK continua as independent input in our analysis and provide an error band for our results. Moreover, we discuss two different methods to include the asymptotic constraints from perturbative QCD. We simultaneously analyze the world data for all four form factors in both the spacelike and timelike regions and generally find good agreement with the data. We also extract the nucleon radii and the \ensuremathωNN coupling constants. For the radii, we generally find good agreement with other determinations with the exception of the electric charge radius of the proton, which comes out smaller. The \ensuremathωNN vector coupling constant is determined relatively well by the fits, but for the tensor coupling constant even the sign cannot be determined.