ENERGY AND SCALE PARAMETER DEPENDENCE OF HEAVY-QUARK PRODUCTION IN QCD

Energy dependences of the cross sections for the production of heavy q uark pairs ccBAR and bbBAR in ppBAR collisions up to the energies squa re-root s = 200 TeV are considered for different values of the scale p arameter mu2. It is shown that, at comparatively small values mu2 almo st-equal-to M2, where M is the heavy quark mass, the K-factors increas e noticeably with increasing energy. For higher values mu2 = 4M2 - 8M2 , the K-factors are virtually independent of energy. The energy depend ences of the cross sections calculated at different values of mu2 have a common point of intersection if the used gluon structure functions obey the correct Q2-evolution law. Heavy quark photoproduction is also considered. The energy dependences of the photoproduction cross secti on calculated at different values of mu2, are also shown to have a com mon point of intersection. The possibility to calculate the total phot oproduction cross section in the framework of perturbative QCD is disc ussed.