Bojak, Ingo2004-12-062004-12-062000-05-22http://hdl.handle.net/2003/2397http://dx.doi.org/10.17877/DE290R-13453This thesis presents the complete details of our calculation of the next-to-leading order (NLO) QCD corrections to heavy flavor photo- and hadroproduction with longitudinally (circularly) polarized photons and hadrons. The main motivation for investigating these processes is the determination of the polarized gluon density. Corresponding measurements will be available from the COMPASS and RHIC experiments, respectively, in the near future. All methods used in the computation are extensively documented and explained, providing a self-contained introduction to this type of NLO calculations. Some of the employed mathematical tools also may be of general interest, e.g., the series expansion of hypergeometric functions. The relevant parton level results are collected and plotted in the form of scaling functions. However, the simplification of the obtained gluon-gluon virtual contributions has not been completed yet. Thus NLO phenomenological predictions at the hadron level are only given in the case of photoproduction. The theoretical uncertainties of these predictions, in particular with respect to the size of the heavy quark mass, are carefully considered. Also it is shown that cuts on the transverse momentum of the produced heavy flavor can considerably enhance the measured production asymmetries. Finally unpolarized heavy quark production is briefly reviewed in order to derive conditions for a successful extraction of the polarized gluon density from future spin-dependent experimental data.enNLOQCDspinPhotoproduktionphotoproductionQuantenchromodynamikquantumchromodynamicsquantum chromodynamicsSchwere Quarksheavy quarksHadroproduktionHadroproductionNext-to-leading order530Text