Quark masses in QCD: a progress report

TL;DR

This paper reports recent advances in determining light and heavy quark masses using QCD sum rules, achieving unprecedented precision by reducing uncertainties through improved experimental data and integration techniques.

Contribution

The paper introduces new integration kernel methods in QCD sum rules that significantly reduce uncertainties in quark mass determinations.

Findings

Light quark masses determined with 8-10% precision.

Heavy quark masses determined with about 1% precision.

Systematic uncertainties due to spectral functions are greatly reduced.

Abstract

Recent progress on QCD sum rule determinations of the light and heavy quark masses is reported. In the light quark sector a major breakthrough has been made recently in connection with the historical systematic uncertainties due to a lack of experimental information on the pseudoscalar resonance spectral functions. It is now possible to suppress this contribution to the 1% level by using suitable integration kernels in Finite Energy QCD sum rules. This allows to determine the up-, down-, and strange-quark masses with an unprecedented precision of some 8-10%. Further reduction of this uncertainty will be possible with improved accuracy in the strong coupling, now the main source of error. In the heavy quark sector, the availability of experimental data in the vector channel, and the use of suitable multipurpose integration kernels allows to increase the accuracy of the charm- and bottom-quarks masses to the 1% level.