On the Extraction of the Strong Coupling from Hadronic Tau Decay
Abstract
The finite energy sum rule extraction of the strong coupling {\alpha}_s from hadronic {\tau} decay data provides one of its most precise experimental determinations. As precision improves, small non-perturbative effects become increasingly relevant to both the central value and error. Here we present a new framework for this extraction employing a physically motivated model to accommodate violations of quark-hadron duality and enforcing a consistent treatment of higher-dimension operator product expansion contributions. Using 1998 OPAL data for the non-strange vector and axial-vector spectral functions, we find the n_f=3 values for {\alpha}_s(m_{\tau}^2) of 0.307(19) for fixed-order perturbation theory and 0.322(26) for contour-improved perturbation theory, corresponding to n_f=5 values for {\alpha}_s(M_Z^2) of 0.1169(25) and 0.1187(32), respectively.
Keywords
Cite
@article{arxiv.1111.5040,
title = {On the Extraction of the Strong Coupling from Hadronic Tau Decay},
author = {Diogo Boito and Oscar Catà and Maarten Golterman and Matthias Jamin and Kim Maltman and James Osborne and Santiago Peris},
journal= {arXiv preprint arXiv:1111.5040},
year = {2011}
}
Comments
7 pages, contribution to Lattice 2011