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arXiv · hep-ph/9302269

Reparametrization invariance and the expansion of currents in the heavy quark effective theory

Matthias Neubert
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Abstract

The coefficients appearing at leading and subleading order in the $1/m$ expansion of bilinear heavy quark currents are related to each other by imposing reparametrization invariance on both the effective current operators and the short-distance coefficient functions in the heavy quark effective theory. When combined with present knowledge about the leading order coefficients, the results allow to calculate all coefficients appearing at order $1/m$ to next-to-leading order in renormalization-group improved perturbation theory. They also provide a meaningful definition of the velocity transfer variable $v\cdot v'$ to order $1/m$.

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Matthias Neubert. 1993-02-17. Reparametrization invariance and the expansion of currents in the heavy quark effective theory. https://doi.org/10.1016/0370-2693(93)90091-u

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