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arXiv · hep-ph/9803363

Next-to-next-to-leading order vacuum polarization function of heavy quark near threshold and sum rules for $b \bar b$ system

A. A. Penin·A. A. Pivovarov
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Abstract

A correlator of the vector current of a heavy quark is computed analytically near threshold in the next-to-next-to-leading order in perturbative and relativistic expansion that includes $\al_s^2$, $\al_sv$ and $v^2$ corrections in the coupling constant and velocity of the heavy quark to the nonrelativistic Coulomb approximation. Based on this result, the numerical values of the $b$-quark pole mass and the strong coupling constant are determined from the analysis of sum rules for the $Υ$ system. The next-to-next-to-leading corrections are found to be of order of next-to-leading ones.

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A. A. Penin, A. A. Pivovarov. 1998-04-06. Next-to-next-to-leading order vacuum polarization function of heavy quark near threshold and sum rules for $b \bar b$ system. https://doi.org/10.1016/s0370-2693(98)00803-x

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