Pseudoscalar mass effects in the decays of τ with three pseudoscalar mesons

We study the dynamical effects of nonvanishing pseudoscalar masses in τ decays into three mesons. The hadronic matrix elements are obtained by using the chiral Lagrangian of the order O(P2), including the quark mass terms which explicitly break the chiral symmetry, and implementing the low-lying resonances in the different channels. We demonstrate that suitable angular distributions are sensitive to the nonconservation of the axial-vector current resulting from the pseudoscalar masses. Numerical results for the relevant structure functions are given for the decay modes τ→νπ-π-π+, νK-π-π+, and νK-π-K+