NATS 1740 Lecture Notes - Lecture 6: Spontaneous Symmetry Breaking, Gauge Theory, Peter Higgs

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Radu Campeanu

Document Summary

Define the following particles: baryons, mesons, hadrons, leptons, fermions, bosons. Describe the standard model of bricks and force carriers. 1st unification was electromagnetism in the 19th century. 2nd unification involved electromagnetism and the weak force. No similarities between electromagnetism (electrical wires, the compass) and the weak nuclear force (the disintegration of nuclei or of heavy leptons). No similarities between their carriers: the photon is neutral and with zero mass, the weakon is usually electrically charged and has a large mass (about 50gev) But in spite of all these differences the two forces were proven to be closely related. 1968 s. weinberg and a. salam unified the gauge field theories corresponding to electromagnetism and weak force. They used a theory which employed zero mass carriers. J. goldstone and p. higgs have shown since 1960 that when nature breaks symmetry it creates some heavy bosons called the higgs bosons. Higgs bosons, like the weakons, rotate only to the left and can be attached to weakons.