Speaker
Dr
Maurice Benayoun
(LPNHE Paris 6/Paris 7)
Description
The Hidden Local Symmetry (HLS) Model provides a framework
able to encompass several physical processes and give a unfied description of these
in an energy range extending up to the $\phi$ mass. However, in order
to account precisely for experimental data, it should be supplied with several
symmetry breaking schemes. Among these, an energy dependent mixing mechanism
of the vector mesons ($\rho^0-\omega-\phi$) is generated via loop effects and
allows to define an effective broken HLS (BHLS) model. Within this framework
the $e^+ e^-$ annihilations to $\pi^+\pi^-$, $\pi^0
\gamma$, $\eta \gamma$, $\pi^+\pi^- \pi^0$, $K^+ K^-$, $K_L K_S$ and the
dipion spectrum in the decay $\tau^\pm \rightarrow \pi^\pm \pi^0 \nu$ are
$simultaneously$ accounted for with the same set of model parameters. These
are derived from global fits in procedures involving all existing data
samples covering the channels within the BHLS scope. The muon HVP's derived
from fits performed with and without the $\tau$ dipion spectra
are found consistent with each other. Therefore, within the broken HLS
approach, one does not observe any clear mismatch between the $\tau$ and $e^+e^- $
physics properties.
Primary author
Dr
Maurice Benayoun
(LPNHE Paris 6/Paris 7)
