Estimate of the systematic error in tau decay due to duality violations

TL;DR

This paper estimates the potential impact of duality violations on tau decay measurements, suggesting they could significantly affect the precision of alpha_s determinations from tau decay data.

Contribution

It introduces a physically motivated ansatz fitted to data to estimate duality violations in hadronic tau decay, highlighting their non-negligible effect on alpha_s measurements.

Findings

Duality violations could impact alpha_s by 0.003-0.010

Uncertainty from violations is significant for precise alpha_s determination

The ansatz provides a method to quantify duality violations in tau decay

Abstract

With the help of a physically motivated ansatz, which is fitted to the data, we estimate the size of possible duality violations in hadronic tau decay. The result is that the uncertainty associated with these violations could impact the alpha_s determination from the total decay width at a level which we estimate to be \delta alpha_s(m_tau) \sim 0.003-0.010. Consequently, it cannot be neglected.