Eur. Phys. J. A 11, 427-440 (2001)
Magnetic moment and radius of the nucleon in a nonlocal model of meson-nucleon interaction
A.Yu. KorchinNational Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov, Ukraine alex_korchin@rbcmail.ru
(Received: 12 February 2001 / Revised version: 6 August 2001 Communicated by V. Vento)
Abstract
Magnetic
moment and radius of the nucleon are calculated in a nonlocal
extension of the chiral linear -model. Properties of the
nonlocal model under the vector and axial transformations are
considered. The conserved electromagnetic and vector currents,
and partially conserved axial vector current are obtained. In the
calculation of the nucleon electromagnetic vertex the
- and
-loop diagrams are included. Contribution from vector mesons
is added in the vector meson dominance model with a gauge-invariant
photon-meson coupling. The nonlocality parameter associated with the
interaction is fixed from the experimental magnetic moment of
the neutron. Other parameters (nonlocality parameter for the
interaction and the mass of the
-meson) are constrained by
the magnetic moment of the proton. The calculated electric and
magnetic mean-square radii of the proton and neutron are in
satisfactory agreement with experiment.
13.40.-f - Electromagnetic processes and properties.
13.40.Em - Electric and magnetic moments.
14.20.Dh - Protons and neutrons.
11.10.Lm - Nonlinear or nonlocal theories and models.
© Società Italiana di Fisica, Springer-Verlag 2001