ENERGY AND SCALE DEPENDENCE OF HEAVY-QUARK PRODUCTION IN QCD

We consider the energy dependence of charm and beauty production cross -sections in pp or ppBAR collisions up to square-root s = 200 TeV for different values of the scale mu2, using different proton structure fu nctions. The cross-sections are computed accounting for leading-order and next-to-leading order perturbative QCD contributions. The values o f K-factors increase significantly with the energy for relatively smal l scale values, mu2 almost-equal-to m2, where M is the heavy-quark mas s, and do not practically depend on the energy for higher values, mu2= 4M2-8M2. The calculated cross-sections as functions of the energy for different values of mu2 have a common crossing point if the gluon str ucture functions used have proper Altarelli-Parisi mu2-evolution. The same holds true when considering the energy and scale dependence of th e heavy-quark cross-sections in high-energy photoproduction.