Class #10 (April 4) Reading Questions - Particle Physics, Secs. 37-46

1. What are the 3 "sectors" of the standard model. Why are particles in the fermion sector divided into multiplets of left and right handedness?

2. According to the text, the standard model consists of 58 particles and has 19 free parameters. Give a summary of the 58 particles (don't list them all individually!) and give as many of the 19 free parameters as you can come up with. (Note: these free parameters include most of the particle masses, the magnitude of the electric and other "charges", and mixing properties like the Cabbibo angle).

3. Explain what is shown Fig. 38.5 and how this data provides experimental support for the idea of asymptotic freedom for the strong interaction. Also explain how this figure is related to Fig. 43.1.

4. What are neutrino-oscillations? Why are these problematic for the standard model?

5. What are GUT's. How are they related to the standard model? What experimental results have ruled out the original and simplest SU(5) GUT proposed by Georgi and Glashow in1974.

6. What is SUSY. The simplest version of SUSY has twice as many free parameters as the standard model, so why would this be a better theory? Is there any experimental evidence for this theory?

7. What is the experimental evidence for the existence of dark matter.

8. Even though the standard model works, many theoretical physicists are dissatisfied with it. What are the weaknesses of the standard model and how are these addressed by string theory?

Your Question: Please give a well-formulated question that you have regarding the material covered in this reading assignment.