Perturbative calculation of O(a) improvement coefficients

Abstract

We compute several coefficients needed for O(a) improvement of currents in perturbation theory, using the Brodsky-Lepage-Mackenzie prescription for choosing an optimal scale q*. We then compare the results to non-perturbative calculations. Normalization factors of the vector and axial vector currents show good agreement, especially when allowing for small two-loop effects. On the other hand, there are large discrepancies in the coefficients of O(a) improvement terms. We suspect that they arise primarily from power corrections inherent in the non-perturbative methods.

14pp, 3 figs (8 plots)

References in corpus (2)

• Application of heavy-quark effective theory to lattice QCD: II. Radiative corrections to heavy-light currents
• Application of heavy-quark effective theory to lattice QCD: III. Radiative corrections to heavy-heavy currents

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