QCD analysis of heavy quarks production in hadronic collisions

The problem of renormalization scheme dependence in QCD perturbation theory remains on obstacle to making precise tests of the theory. The renormalization scale dependence of dimensionless physical QCD observable, depending on a single energy scale Q, can be avoided provided that all ultraviolet logarithms which build the physical energy dependence on Q are resummed. This was termed complete Renormalization Group improvement(CORGI). This argument can be extended to processes involving factorization of operator matrix elements and coefficient functions. We are trying to employ the idea of CORGI approach on analyzing of heavy quarks production in hadron collisions. There is a sizable and systematic discrepancy between experimental data on the production in , γp and γγ collisions and existing theoretical calculations within perturbative QCD. One suggested way to cope with this discrepancy is to employ the CORGI approach in which one should perform a resummation to all-orders of renormalization and factorization group -predictable terms at each order of perturbation theory. Then the scales dependence will be avoided and it is expected that the mentioned discrepancy is reduced significantly.