Strange quark mass from pseudoscalar sum rule with accuracy
Institut für Theoretische Teilchenphysik, Universität Karlsruhe, 76128, Karlsruhe, Germany
2 Theoretische Physik 1, Fachbereich Physik, Universität Siegen, 57068, Siegen, Germany
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Published online: 30 March 2006
We include the new, five-loop, O(αs 4) correction into the QCD sum rule used for the s-quark mass determination. The pseudoscalar Borel sum rule is taken as a study case. The OPE for the correlation function with N4LO, O(αs 4) accuracy in the perturbative part, and with dimension d≤6 operators reveals a good convergence. We observe a significant improvement of stability of the sum rule with respect to the variation of the renormalization scale after including the O(αs 4) correction. We obtain the interval m̄s(2 GeV)=105±6±7 MeV, which exhibits about 2 MeV increase of the central value, if the O(αs 4) terms are removed.
© Springer-Verlag, 2006