Unraveling duality violations in hadronic tau decays

TL;DR

This paper investigates duality violations in hadronic tau decays using a physical model, highlighting potential systematic errors in alpha_s determination and proposing an alternative method to estimate OPE coefficients.

Contribution

It introduces a physically motivated model to analyze duality violations and suggests a new approach for estimating OPE coefficients to reduce systematic errors.

Findings

Duality violations can cause significant systematic errors in alpha_s extraction.

A new method for estimating OPE coefficients may help mitigate these errors.

Duality violations could impact the accuracy of current tau decay analyses.

Abstract

There are some indications from recent determinations of the strong coupling constant alpha_s and the gluon condensate that the Operator Product Expansion may not be accurate enough to describe non-perturbative effects in hadronic tau decays. This breakdown of the Operator Product Expansion is usually referred to as being due to ``Duality Violations.'' With the help of a physically motivated model, we investigate these duality violations. Based on this model, we argue how they may introduce a non-negligible systematic error in the current analysis, which employs finite-energy sum rules with pinched weights. In particular, this systematic effect might affect the precision determination of alpha_s from tau decays. With a view to a possible future application to real data, we present an alternative method for determining the OPE coefficients that might help estimating, and possibly even reducing, this systematic error.