https://doi.org/10.1140/epja/i2012-12190-6
Regular Article - Theoretical Physics
Electromagnetic transitions in an effective chiral Lagrangian with the 
and light vector mesons
1
Institutionen för fysik och astronomi, Uppsala Universitet, Box 516, 75120, Uppsala, Sweden
2
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstraße 1, 64291, Darmstadt, Germany
* e-mail: stefan.leupold@physics.uu.se
Received:
8
October
2012
Revised:
2
November
2012
Accepted:
15
November
2012
Published online:
20
December
2012
We consider the chiral Lagrangian with a nonet of Goldstone bosons and a nonet of light vector mesons. The mixing between the pseudoscalar mesons 
and 
is taken into account. A novel counting scheme is suggested that is based on hadrogenesis, which conjectures a mass gap in the meson spectrum of QCD in the limit of a large number of colors. Such a mass gap would justify to consider the vector mesons and the meson as light degrees of freedom. The complete leading-order Lagrangian is constructed and discussed. As a first application it is tested against electromagnetic transitions of light vector mesons to pseudoscalar mesons. Our parameters are determined by the experimental data on photon decays of the 
, 
and mesons. In terms of such parameters we predict the corresponding decays into virtual photons with either dielectrons or dimuons in the final state.
© SIF, Springer-Verlag Berlin Heidelberg, 2012
