Theoretical inputs and errors in the new hadronic currents in TAUOLA

TL;DR

This paper discusses the development of hadronic currents in TAUOLA based on Resonance Chiral Theory, addressing theoretical consistency, error estimates, and improvements in modeling tau decays.

Contribution

It introduces a unified framework for hadronic currents in TAUOLA using Resonance Chiral Theory, with analysis of errors and phenomenological implications.

Findings

Resonance Chiral Theory provides a predictive approach for tau decay form factors.

Estimated errors are smaller than previously claimed, supporting the model's accuracy.

Improvements in the TAUOLA code enhance its reliability for decay simulations.

Abstract

The new hadronic currents implemented in the TAUOLA library are obtained in the unified and consistent framework of Resonance Chiral Theory: a Lagrangian approach in which the resonances exchanged in the hadronic tau decays are active degrees of freedom included in a way that reproduces the low-energy results of Chiral Perturbation Theory. The short-distance QCD constraints on the imaginary part of the spin-one correlators yield relations among the couplings that render the theory predictive. In this communication, the obtaining of the two- and three-meson form factors is sketched. One of the criticisms to our framework is that the error may be as large as 1/3, since it is a realization of the large-N_C limit of QCD in a meson theory. A number of arguments are given which disfavor that claim pointing to smaller errors, which would explain the phenomenological success of our description in these decays. Finally, other minor sources of error and current improvements of the code are discussed.