Particle Physics Questions

Part 1 (Physics)

After a review of the pages linked from the Physics section (including those references contained in the introductory remarks and under the figures), you should be able to answer all of the following questions. Note the key vocabulary words are in italics. Pay particular attention to the Standard Model and Particle Fireworks.

1. What is the diameter of a proton in meters and in fermi? Approximately how many protons can fit on the head of a pin? Define what you mean by ‘fit’ and show your reasoning.

2. What is the meaning of the term fundamental particle? List a few fundamental and non-fundamental particles.

3. List three characteristics that distinguish fermions from bosons. List three characteristics that distinguish mesons from baryons. Are there such things as fermionic baryons? How about bosonic baryons?

4. What are some characteristics that distinguish the leptons from other kinds of fermions?

5. Explain the 7 major conservation laws used in particle physics. How do these laws explain the types of particle reactions that may or may not occur?

6. What do you change about a given particle to make it’s anti-particle? What types of particles are their own anti-particles?

7. What are the constituent particles of the neutron and the proton? Explain how the characteristics of the neutron and proton are determined by their constituent particles.

8. Use ‘From Quarks to Hadrons’ in Particle Fireworks to build a proton and an anti-proton. Then build two mesons and two baryons of any type other than those you’ve already built. Report the constituents and the characteristics of each particle that you build.

9. Use ‘Hadron Decay’ in Particle Fireworks to explain how a neutron can decay into a proton and an electron (include any other stuff that must take part in the reaction). Then do any two of the other decays shown. Report each completed reaction (with all intermediate steps) in the form of a vertex diagram. It may help to refer to Feynmann diagrams.

10. How does the Standard Model explain the interaction that we usually call the electromagnetic force? How does the model explain the weak interaction? What does the Standard Model have to say about gravity?

11. What is meant by quark confinement? Why are the masses of hadrons larger than the sum of the masses of their constituent quarks?

12. What must a particle contain in order to ‘feel’ the strong interaction?

13. What types of fundamental particles are among the most weakly interacting? What types of experiments are being done to detect these particles?

14. In 1995, FermiLab experiments ‘discovered’ the top quark. Was this particle actually observed in the course of these experiments? What signatures were used to find the top quark?

15. How many of the Nobel Prizes awarded in Physics since 1975 have been for particle physics research?