Hadronic structure in tau- -> pi- pi- pi+ neutrino decays

TL;DR

This paper analyzes the hadronic substructure in tau- decays to three pions and neutrino, revealing dominant resonant processes involving the a1(1260) and rho0, and supporting previous findings on decay modes.

Contribution

It provides a model-dependent analysis of the substructure in tau- -> pi- pi- pi+ neutrino decays, highlighting the dominance of specific resonant decay channels.

Findings

Tau- decays are dominated by tau- -> a1(1260)- + neutrino

a1(1260)- predominantly decays into rho0 pi- in S-wave

Decays via pi(1300)- are small

Abstract

A model-dependent analysis of the hadronic substructure in tau- -> pi- pi- pi+ neutrino decay is reported. The decay is dominated by the process tau- -> a1(1260)- + neutrino, in which a1(1260)- -> rho0 pi- in an S-wave decay. Amplitudes involving a1(1260) decays into isoscalars, especially a_1(1260)- -> f0(600)pi-, are large. tau- -> pi- pi- pi+ neutrino decays via the pseudoscalar pi(1300)- are small. These results support the resonant substructure reported in the previously reported analysis of tau- -> pi0 pi0 pi- neutrino decay mode from the same CLEO II data sample.