1208.1212 (Daniel Gómez Dumm et al.)

$τ^- \to η^{(\prime)} π^- π^0 ν_τ$ decays in Resonance
Chiral Theory    [PDF]

Daniel Gómez Dumm, Pablo Roig

The hadronization structure of $\tau^- \to \eta \pi^- \pi^0 \nu_\tau$ decays is analyzed within the framework of Resonance Chiral Theory, considering only the contribution of the lightest meson resonances at leading order in the $1/N_C$ expansion. After imposing the asymptotic behavior of vector spectral functions ruled by QCD, unknown effective couplings are determined by fitting the $\tau^- \to \eta \pi^- \pi^0 \nu_\tau$ branching ratio and decay spectrum to recent data. Predictions for the partner decay $\tau^- \to \eta^\prime \pi^- \pi^0 \nu_\tau$ and the low-energy behavior of the cross section $\sigma (e^+e^-\to \eta\pi^+\pi^-)$ are also discussed.

View original: http://arxiv.org/abs/1208.1212