2013/07/08 by Schumacher, Martin
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.1307.2215
Based on Compton scattering and meson photoproduction data the polarizabilities of the nucleon are precisely studied and well understood due to recent experimental and theoretical work based on nonsubtracted dispersion relations. The \it recommended experimental values are αp=12.0± 0.6, (12.0), βp=1.9∓ 0.6, (1.9), αn=12.5± 1.7, (12.7± 0.9), βn=2.7∓ 1.8, (2.5∓ 0.9) in units of 10-4fm3 and γ(p)π=-36.4± 1.5, (-36.6), γ(n)π=+58.6± 4.0, (58.3), (γ(p)0=-0.58± 0.20), γ(n)0=0.38± 0.22) in units of 10-4fm4 [1]. The numbers given in parentheses are predicted values. It is shown that all versions of chiral effective field theories applied in analyses of nucleon polarizabilities and Compton scattering ignore essential effects of ω, ρ and σ exchanges and of pseudoscalar πN coupling.