New contributions to heavy quark sum rules
Abstract
We analyse new contributions to the theoretical input in heavy quark sum rules and we show that the general theory of singularities of perturbation theory amplitudes yields the method to handle these specific features. In particular we study the inclusion of heavy quark radiation by light quarks at O(alpha_s^2) and non-symmetric correlators at O(alpha_s^3). Closely related, we also propose a solution to the construction of moments of the spectral densities at O(alpha_s^3) where the presence of massless contributions invalidates the standard approach. We circumvent this problem through a new definition of the moments, providing an infrared safe and consistent procedure.
Keywords
Cite
@article{arxiv.hep-ph/0202114,
title = {New contributions to heavy quark sum rules},
author = {J. Portoles and P. D. Ruiz-Femenia},
journal= {arXiv preprint arXiv:hep-ph/0202114},
year = {2011}
}
Comments
15 pages, 3 figures. Version accepted for publication in The European Journal of Physics C; several new comments and references added, conclusions unchanged