A Global Treatment Of VMD Physics Up To The $ϕ$: I. $e^+e^-$ Annihilations, Anomalies And Vector Meson Partial Widths

Abstract

The HLS Model, equipped with a mechanism providing the breaking of U(3)/SU(3) symmetry and an isospin symmetry breaking leading naturally to vector meson mixing, has been recently shown to successfully account for $e^+ e^- \ra π^+π^-$ cross section and for the dipion spectrum in $τ$ decay. The present study shows that the full anomalous sector of the HLS model can be considered and is validated by the experimental data. Indeed, this extended model provides a successful simultaneous fit to the $e^+ e^- \ra π^+π^-$ data together with the available data on $e^+ e^- \ra π^0γ$, $e^+ e^- \ra ηγ$ and $e^+ e^- \ra π^0 π^+π^-$ cross sections. It is shown that the fit of these data sets also predicts an accurate description of the $η/η^\prime \ra π^+ π^- γ$ decays fully consistent with the reported information on their branching fractions and spectra. Finally, one also derives from our global fits products of widths of the form $Γ(V \ra f_1)Γ(V \ra e^+ e^-) $ and ratios of the form $Γ(V \ra f_1)/Γ(V \ra f_2)$ describing decays of vector mesons to several non--leptonic final states.

58 pages, 10 figures Corrected a few misprints. Footnote 10 changed