Resonance Chiral Lagrangian analysis of tau --> eta (prime) pi- pi0 nu_tau decays

DANIEL GOMEZ DUMM; PABLO ROIG

PHYSICAL REVIEW D

AMER PHYSICAL SOC

Lugar: New York; Año: 2012 vol. 86 p. 760091 - 7600910

1550-7998

The hadronization structure of

tau- --> eta pi- pi0 nu_tau  decays is analyzed using chiral perturbation theory with resonances, considering only the contribution of the lightest meson resonances at leading order in the 1/Nc expansion. After imposing the asymptotic behavior of vector spectral functions ruled by QCD, unknown effective couplings are determined by fitting the

tau- --> eta pi- pi0 nu_tau  branching ratio and decay spectrum to recent data. Predictions for the partner decay

tau- --> eta prime pi- pi0 nu_tau
  and the low-energy behavior of the cross section  sigma( e+e- --> eta pi+ pi- ) are also discussed.