arXiv:hep-ph/9505406·v1·High Energy Physics — Phenomenology
Momentum Sum Rules in QCD for a Photon Target
L.L.Frankfurt🇮🇱 · E.G.Gurvich (School of Physics and Astronomy, Tel Aviv University)🇮🇱
Abstract
We deduce momentum sum rules for the parton structure functions of a photon target. Non-perturbative QCD contribution to the momentum sum rules follows from conservation of the energy--momentum tensor and it is calculated through the hadronic part of the photon vacuum polarization operator. The contribution of the unresolved photon unambiguously follows from gauge invariance, renormalizability and asymptotic freedom in QCD. We also compare available parametrizations of parton distribution in a photon with the deduced sum rules.
Comments: Revtex, uses epsfig.sty, 2 eps figures