On the photon energy moments and their ‘bias’ corrections in image Original Research Article

Photon energy moments in image and the impact of experimental cuts are analyzed, including the biases exponential in the effective hardness missed in the conventional OPE. We incorporate the perturbative corrections fully implementing the Wilsonian momentum separation ab initio. This renders perturbative effects numerically suppressed while leaving heavy quark parameters and the corresponding light-cone distribution function well defined and preserving their physical properties. The moments of the distribution function are given by the heavy quark expectation values of which many have been extracted from the image decays. The quantitative estimates for the biases in the heavy quark parameters determined from the photon moments show they cannot be neglected for image, and grow out of theory control for image above 2.1 GeV. Implications for the moments in the image decays at high cuts are briefly addressed.