Quantum Field Theory II

The course continues where Quantum Field Theory I finishes. First higher order perturbations in QED are studied and then the theory is made finite through so called regularisation where masses and charges are renormalized. Thereafter gauge theories, where interaction is introduced by making global symmetries local, are treated. Then it is shown how particle masses may be obtained through spontaneous symmetry breaking, like the Goldstone and Higgs mechanisms. The rest of the course is devoted to the Electro-weak theory where it e.g. is shown how the vector bosons acquire mass through the Higgs mechanism. Then the theory is used to calculate cross sections for different processes.