Investigation of the factorization scheme dependence of finite order   perturbative QCD calculations
  The freedom associated with the definition of parton distribution functions is analyzed and formulae governing the dependence of parton distribution functions and hard scattering cross-sections on unphysical quantities associated with the renormalization and factorization procedure are derived. The issue of the specification of factorization schemes via the corresponding higher order splitting functions is discussed in detail. A numerical analysis of the practical applicability of the so called ZERO factorization scheme, which could be useful for the construction of consistent NLO Monte Carlo event generators, is presented. 
Karel Kolar
hep-ph hep-th