Meson dominance in the 'second class'τ→ηπντdecay

Motivated by recent estimates of the isospin-violating process $\ensuremath{\tau}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\pi}{\ensuremath{\nu}}_{\ensuremath{\tau}}$, mostly relying on the $\ensuremath{\rho}$ and ${a}_{0}$ dominance of the relevant form factors near threshold, we present an assessment for the branching ratio that accounts for additional, potential effects from the lowest radial excitations ${\ensuremath{\rho}}^{\ensuremath{'}}\ensuremath{\equiv}\ensuremath{\rho}(1450)$ and ${a}_{0}^{\ensuremath{'}}\ensuremath{\equiv}{a}_{0}(1450)$, respectively, also lying in the decay phase space.