ИСТИНА

In general, heavy flavour production at hadron colliders is reasonably well understood using the collinear approach. But especially angular correlations between the produced heavy quarks reveal the necessity of further investigations, since the data are not fully described in this region. Here, non-collinear gluon evolution dynamics are expected to dominate the scenario. Therefore, we studied heavy flavour production at the Tevatron in the non-collinear approach by comparing the data to numerical calculations and to predictions of the hadron-level Monte Carlo generator CASCADE. We focus on parton shower effects and the influences of different unintegrated parton density functions. Studies of systematic uncertainties are also presented. We observe, that the non-collinear approach is able to describe heavy flavour production at Tevatron within the systematic uncertainties.