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Gluon condensate and c-quark mass in pseudoscalar sum rules at 3-loop order

K. Zyablyuk
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Abstract

Charmonium sum rules for pseudoscalar 0^{-+} state eta_c(1S) are analyzed within perturbative QCD and Operator Product Expansion. The perturbative part of the pseudoscalar correlator is considered at alpha_s^2 order and the contribution of the gluon condensate is taken into account with alpha_s correction. The OPE series includes the operators of dimension D=6,8 computed both in the instanton and factorization model. The method of moments in MS-bar scheme allows to establish acceptable values of the charm quark mass and gluon condensate, using the experimental mass of eta_c. In result of the analisys the charm quark mass is found to be m_c(m_c)=1.26+-0.02 GeV independently of the condensate value. The sensitivity of the results to various approximations for the massive 3-loop pseudoscalar correlator is discussed.

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K. Zyablyuk. 2003-02-03. Gluon condensate and c-quark mass in pseudoscalar sum rules at 3-loop order. https://doi.org/10.1088/1126-6708%2F2003%2F01%2F081

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