Light- and strange-quark mass dependence of the ρ(770) meson revisited

Mass singularities in light quark correlators: The strange quark case.

The correlators of light-quark currents contain mass-singularities of the form log(m 2 /Q 2). It has been known for quite some time that these mass-logarithms can be absorbed into the vacuum expectation values of other operators of appropriate dimension, provided that schemes without normal-ordering are used. We discuss in detail this procedure for the case of the mass logarithms m 4 log(m 2 /Q...

Strange Quark Mass Dependence of the Tau Hadronic

The perturbative quark mass corrections to the tau hadronic width are studied to O(αs m 2 q). Including up to dimension four corrections, we get ms(4GeV ) = (143 ± 42) MeV [ms(1GeV ) = (193 ± 59) MeV ]. Possible improvements to reduce the theoretical uncertainty are pointed out. September 1998 Invited talk at “High Energy Conference on Quantum Chromodynamics (QCD ’98)”, 2-8 July 1998, Montpelli...

Quark Mass dependence at Two Loops for Meson Properties

This talks contains a short introduction to Chiral Perturbation Theory and the existing calculations to two-loop order in the mesonic sector. I include a discussion on which quantities the expansion can be organized in. The present best values of the Low-Energy-Constants as determined from continuum physics are given as well as the assumptions underlying the fits to experimental data. I present...

Lattice Determination of the Strange Quark Mass

Lattice determinations of the strange quark mass

The importance of the strange quark mass, as a fundamental parameter of the Standard Model (SM) and as an input to many interesting quantities, has been highlighted in many reviews, eg in Ref [1]. A first principles calculation of ms is possible in lattice QCD but to date there has been a rather large spread in values from lattice calculations. This review aims to clarify the situation by expla...