A relativistic quark model for mesons with an instanton-induced interaction
M. Koll - R. Ricken - D. Merten - B.C. Metsch - H.R. Petry
Institut für Theoretische Kernphysik, Nußallee 14-16, D-53115 Bonn, Germany
Received: 28 August 2000
Communicated by V.V. Anisovich
Abstract
We present new results of a relativistic quark model based on the
Bethe-Salpeter equation in its instantaneous approximation.
Assuming a linearly rising confinement potential with an
appropriate spinorial structure in Dirac space and adopting a residual
interaction based on instanton effects, we can compute
masses of the light mesons up to highest observed angular momenta with
a natural solution of the UA(1) problem. The calculated ground
states masses and the radial excitations describe the experimental results well.
In this paper, we will also discuss our results concerning numerous
meson decay properties. For processes like
and
at various photon virtualities,
we find a good agreement with experimental data. We will also comment
on the form factors of the
decay and on the decay
constants of the 
,
K and 
mesons. For the sake of
completeness, we will furthermore present the electromagnetic form
factors of the charged
and K mesons as well as a comparison of the
radiative meson decay widths with the most recent experimental data.
PACS
11.10.St Bound and unstable states; Bethe-Salpeter equations - 12.39.Ki Relativistic quark model - 12.40.Yx Hadron mass models and calculations - 14.65.Bt Light quarks
Copyright Società Italiana di Fisica, Springer-Verlag 2000
