Baryons as Solitons in Effective Chiral Field Theories

Abstract

This lecture comprises some recent developments concerning the description of baryons as topological solitons in effective chiral meson theories. In the first part one-loop corrections to the classical tree approximation are discussed. This involves renormalization of low-energy coupling constants and evaluation of the finite next-to-leading-order terms in the $1/N_c$ expansion. Recent results for various nucleon observables are presented. In the second part electromagnetic nucleon form factors (FFs) with relativistic corrections are evaluated in a chiral soliton model including vector mesons. The magnetic FF $G_M^p$ is shown to agree well with new SLAC data for spacelike $Q^2$ up to 30(GeV/c)$^2$ if superconvergence is enforced. The electric FF $G_E^p$ is dominated by a zero in the few (GeV/c)$^2$ region. The third part describes how to extract the strong $πNN$ form factor from chiral soliton models, taking due care of the local metric created by the presence of the soliton. When used in a one-boson-exchange model for the nucleon-nucleon (NN) interaction, deuteron properties and phase parameters of NN scattering are reproduced as well as in conventional NN models that apply a hard monopole form factor at the $πNN$ vertex.