Parton momentum and helicity distributions in the nucleon

摘要

We review the current status of spin-averaged and spin-dependent partondistribution functions (PDFs) of the nucleon. After presenting the formalismused to fit PDFs in modern global data analyses, we discuss constraints placedon the PDFs by specific data types. We give representative examples ofunpolarized and polarized PDFs and their errors, and list open questions inglobal QCD fitting. Finally, we anticipate how future facilities, withfixed-target and collider experiments, may impact our knowledge of PDFs andreduce their uncertainties.