Dispersive analysis of ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ Belle data

Abstract

We analyse Belle data on the decay ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ using a dispersive representation of the vector form factor which is consistent with chiral symmetry and preserves analyticity and unitarity exactly. We fit the unknown theoretical parameters from the data, determining the values of the related low-energy observables ${⟨r^2⟩}_V^{\pi }$ and $c_V^{\pi }$. The implementation of isospin breaking effects is also discussed.

4 pages, no figures, presented at the Conference TAU'12 (Nagoya, Japan). To be published in the Proceedings

References in corpus (6)

• Towards a consistent estimate of the chiral low-energy constants
• K pi vector form factor, dispersive constraints and tau -> nu_tau K pi decays
• One meson radiative tau decays
• Dispersive representation of the pion vector form factor in $\tau \to \pi \pi {\nu }_{\tau }$ decays
• Long-distance radiative corrections to the di-pion tau lepton decay
• Resonance Chiral Lagrangian analysis of ${\tau }^{-}\to {\eta }^{(\prime )}{\pi }^{-}{\pi }^0{\nu }_{\tau }$ decays