https://doi.org/10.1140/epja/i2007-10492-4
Regular Article - Theoretical Physics
A gauge-invariant chiral unitary framework for kaon photo- and electroproduction on the proton
1
Helmholtz-Institut für Strahlen- und Kernphysik (Theorie), Universität Bonn, Nußallee 14-16, D-53115, Bonn, Germany
2
Institut für Kernphysik (Theorie), Forschungszentrum Jülich, D-52425, Jülich, Germany
* e-mail: bruns@itkp.uni-bonn.de
Received:
21
September
2007
Accepted:
12
October
2007
Published online:
12
November
2007
We present a gauge-invariant approach to photoproduction of mesons on nucleons within a chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the chiral effective Lagrangian and iterated in a Bethe-Salpeter equation. Within the leading-order approximation to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and CBELSA/TAPS are analyzed in the threshold region. The importance of gauge invariance and the precision of various approximations in the interaction kernel utilized in earlier works are discussed.
PACS: 13.60.Le Meson production – / 25.20.Lj Photoproduction reactions – / 12.39.Fe Chiral Lagrangians –
© Società Italiana di Fisica and Springer-Verlag, 2007