HERMES - ein neues HERA-Experiment zur Klärung des Spinrätsels

摘要

In 1987, the spin distribution of the quarks in the proton was determined by the European Myon Collaboration (EMC) at CERN [1]. The results were in contradiction with the current ideas and predictions and surprised the professional world so much that a spin crisis "of the Quark-Parton model was spoken [2]. In the last eight years, there have been great advances both in the theoretical understanding of the spin distributions of the quarks in the QCD and in the experimental field by new experiments at CERN and the SLAC. Nevertheless, there are still more open questions than answers. The HERMES experiment at the HERA storage ring at DESY [3] is an entirely new type of experiment. His goal is to provide comprehensive and precise insights into the internal spin structure of Proton and Neutron using novel technologies.