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.
@article{arxiv.hep-lat/0208004,
title = {Perturbative calculation of O(a) improvement coefficients},
author = {Junpei Harada and Shoji Hashimoto and Andreas S. Kronfeld and Tetsuya Onogi},
journal= {arXiv preprint arXiv:hep-lat/0208004},
year = {2009}
}