Quark masses in QCD: a progress report

Understand

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%.