1. The cross section ratio R of (18-6) is based on the quark-parton model. This result is altered slightly in QCD because of the appearance of gluons. Considering what happens to hadronic jets as the energy increases, in what direction would you expect R to change due to QCD corrections and why?
2. In what way is the non-Abelian nature of QCD essential in converting the global symmetry of color to a local symmetry? Why can the same result be achieved in Abelian QED?