Studies of parton distributions in nuclei

The subject of this thesis is the global analysis of nuclear parton distribution functions (nPDFs). The main goal of the project is to determine a new set of nPDFs at next-to-next-to-leading order (NNLO) in perturbative quantum chromodynamics (pQCD) and to make it publicly available for the scientific community. The purpose of nPDFs is to describe the collinear momentum distribution of the partons (quarks and gluons) inside nucleons which are bound to a nucleus. The increase in perturbative precision in the nPDF determination enables the application of the most accurate calculations for the partonic scattering processes with nuclei. Furthermore, the improved accuracy of nPDFs is important for the analysis of the heavy-ion experiments, and also to make predictions for future research projects. The framework of the performed analysis, including the form of the initial parameterization of PDFs as well as the included data sets from deeply inelastic scattering (DIS) experiments are described. The performed uncertainty analysis and the results of an alternative method of error analysis applied for the obtained nPDFs are discussed. The results of the QCD analysis in this thesis are compared to the existing nPDF sets and to the fitted data. Finally, a study on further processes, i.e. Drell-Yan and W, Z boson production, is presented and an outlook is given.