On the non-perturbative part of the photon structure function
نویسنده
چکیده
We discuss a dispersion relation in the photon mass and show how (in principle) model-independent constraints on the parton distribution functions of the photon, notably a momentum sumrule, can be obtained. We present two sets of parametrizations, SaS 1 and 2, corresponding to two rather extreme realizations of the non-perturbative part. Inclusive electron scattering off a real photon is found to be insufficient to constrain the non-perturbative components. The additional sensitivity provided by the photon virtuality is outlined. Previous approaches to model the non-perturbative input distributions are commented upon. a Talk presented at the Xth Workshop on Photon–Photon Collisions, Photon ’95, Sheffield, England, 8–13 June 1995 CERN–TH/95–153 June 1995
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