An effective approach to VMD at one loop order
and the departures from ideal mixing for vector mesons
1 LPNHE des Universités Paris VI et VII-IN2P3, Paris, France
2 Stanford Linear Accelerator Center, Stanford University, Stanford CA 94309, USA
Received: 5 April 2000 / Revised version: 8 June 2000 /
Published online: 31 August 2000 - © Springer-Verlag 2000
We examine the mechanisms producing departures from ideal mixing for vector mesons within the context of the Hidden Local Symmetry (HLS) model. We show that kaon loop transitions between the ideal combinations of the and mesons necessitate a field transformation in order to get the mass eigenstates. It is shown that this transformation is close to a rotation for processes involving, like meson decays, on-shell and mesons. The HLS model predicts a momentum dependent, slowly varying mixing angle between the ideal states. We examine numerically the consequences of this for radiative and leptonic decays of light mesons. The mean mixing angle is found smaller than its ideal value; this is exhibited separately in radiative and in leptonic decays. Effects of nonet symmetry breaking in the vector sector are compared to those produced by the field rotation implied by the HLS model.
Copyright Società Italiana di Fisica, Springer-Verlag 2000