Optimal renormalization and the extraction of the strange quark mass from moments of the $\tau$-decay spectral function

TL;DR

This paper develops an optimal renormalization group method for analyzing the strange quark mass from tau decay spectral functions, reducing scale sensitivity and improving perturbative series convergence.

Contribution

It introduces a new renormalization group technique that sums leading and next-to-leading logarithms, enhancing the precision of strange quark mass extraction from tau decay data.

Findings

Extracted $m_s(2{ m GeV})$ as 106.70 ± 9.36 MeV from ALEPH data.

Derived $m_s(2{ m GeV})$ as 74.47 ± 7.77 MeV from OPAL data.

Results agree with other phenomenological and lattice determinations.

Abstract

We introduce an optimal renormalization group analysis pertinent to the analysis of polarization functions associated with the $s$-quark mass relevant in $\tau$-decay. The technique is based on the renormalization group invariance constraints which lead to closed form summation of all the leading and next-to-leading logarithms at each order in perturbation theory. The new perturbation series exhibits reduced sensitivity to the renormalization scale and improved behavior in the complex plane along the integration contour. Using improved experimental and theory inputs, we have extracted the value of the strange quark mass $m_s(2{\rm GeV}) = 106.70 \pm 9.36~{\rm MeV}$ and $m_s(2{\rm GeV}) = 74.47 \pm 7.77~{\rm MeV}$ from presently available ALEPH and OPAL data respectively. These determinations are in agreement with the determinations in other phenomenological methods and from the lattice.