Scale dependence of heavy quark production in pp and $bar{mathbf{p}}$p collisions - transverse momentum dependence

The dependence of the differential cross section ${mathrm{d}sigma}/{mathrm{d}p_{perp}}$ of inclusive heavy quark production in pp and $bar{mathrm{p}}$p collisions on the renormalization and factorization scales is investigated. The implications of our results for experiments at TEVATRON and LHC are discussed. In particular, it is shown that the NLO QCD predictions for $bar{t}t$ production at the LHC based on the Principle of Minimal Sensitivity are by 30-50% higher than the standard ones.