HIGH-ENERGY FACTORIZATION PREDICTIONS FOR THE CHARM STRUCTURE-FUNCTION F-2(C) AT HERA

High-energy factorization predictions for F-2(c) are derived using BFK L descriptions of the proton structure function F-2 at HERA. The model parameters are fixed by a fit of F-2 at small x. Two different approa ches of the non-perturbative proton input are shown to correspond to t he factorization at the gluon or quark level, respectively. The predic tions for F-2(c) are in agreement with the data within the present err or bars. However, the photon wave-function formulation (factorization at quark level) predicts significantly higher F-2(c) than both gluon f actorization and a next-leading order DGLAP model. (C) 1998 Elsevier S cience B.V.