Class #3 (Jan. 24) Reading Questions - Particle Physics, Secs. 5-8

1. The neutrino was predicted decades before it was actually observed. What was the experimental evidence for the existence of this particle? Why is this particle so hard to detect?

2. What is Noether's theorem? What symmetry property of the Lagrangian is associated with the conservation of electric charge?

3. What measurable quantity is associated with isospin? Based on Heisenberg's original ideas about isospin, which would we logically expect to have a greater mass, the proton or the neutron?

4. Pions have isospin I=1 and form an isospin triplet (i.e., a 3 particle isospin multiplet). How may particles would be in the isospin multiplet for I=3/2? If these particles have B=1 and S=0 what would their charges be?

5. What was originally considered "strange" about strange particles?

6. K-mesons come in 3 charge states like the pions but the K-mesons can not form an isospin triplet. Why not?

7. Q, B, and S can be considered particle quantum numbers. Which of these are conserved in strong interactions? Which are conserved in weak interactions?

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