| Prof. Rory Coker
Office: RLM 8.312
Phone: (512) 471-5194
Fax: (512) 471-9637
Email: rory coker's civilian mail, coker's physics department mail
Office Hours: Friday, 1:30 to 3:30 PM.
The Spring 2019 unique number is 55590; the class meets from 12 to 1 PM MWF in RLM 5.104. The TA is Josiah Couch. Office: RLM 9.308. Hours: 9-10 AM on Mondays and Wednesdays.
Text: SUBATOMIC PHYSICS, 3rd Edition, by Henley and Garcia (World Scientific, 2007, 2010). Errata for Ch. 6, and errata for Ch. 11. [I have located a free pdf version of the text, here.] And here is a very compact introduction to the theory of scattering. A short course in nuclear physics. Highly recommended supplementary text: PARTICLES AND NUCLEI, 7th edition, by Povh, Rith, Scholz, Zetsche and Rodejohann (Springer, 2015). The only reason I don't use this as the primary text is that it has no homework problems.Syllabus and first day handout. Basis of course letter grade: Homework 85%, daily pop quizzes 15%.
Other books on course topics:
RUNNING TABLE OF HOMEWORK DUE DATES AND TIMES: HW 1 statistics: 18 students turned in the assignment. High grade 91%, low grade 45%, average 75%. HW 2 statistics: 22 students turned in the assignment. High grade 100%, low grade 0%, average 67%. HW 3 statistics: turned in by 22 students. Highest grade 93%, lowest grade 62%, average grade 73%. HW 4 statistics, high grade 97.5%, low grade 19%, average 80%, turned in by 20 students. HW 5, due in class on March 27. HW 6, due in class on April 3. HW7, due in class April 10.
Answers to in-class quizzes: (1) The Feynman diagram is for pair creation. Since the photon is massless and the electron and positron have a mass of 0.5 MeV, total energy and momentum can't be conserved unless another massive object (the nucleus of a heavy atom) is also involved in the initial state of the process. (2) Clearly a system made of a particle and an antiparticle is not going to be stable. What's astonishing is that all strongly-interacting composite particles can be put into two groups, baryons and mesons, and it turns out no meson is stable, and only one baryon seems to be stable, the proton. (3) Typical average lifetimes: strong processes, 10−23 sec; electromagnetic processes, 10−17 sec; weak processes, 10−10 sec, as you would expect. (4) The neutral D decay involves a W+ boson, the gauge boson of the weak force. (5) Isospin obeys the same rules as angular momentum, so isospin T results in a 2T+1 multiplet. Since 2T+1 = 5, T = 2. (6) The Poynting Vector is a cross product of a polar vector E and an axial vector B. So it transforms like a polar vector. PS = -SP. (7) Photons emitted by pointlike fundamental particles are virtual. (8) A negative pion decaying to a muon and an anti-muon-neutrino is of course a semi-leptonic process. (9) ALL of the statements about the weak interaction are correct. (10) The original quark model (1961) used only 3 quarks, u, d and s. (11) The spectra of 64Zn and 122Te exhibit the classic pattern of vibrational nuclei... a one phonon (λ = 2) state and then a triplet indicating excitation of two coupled λ = 2 phonons. If you missed this straightforward question, take it as a warning that you are not now keeping up in the class or comprehending even very basic material. (12) If a nucleus has a half-life of one day, and at some point a sample contains 10,000 such nuclei, one day later there will be 5,000. (13) 48% comes from diagnostic X-radiation, and 37% from radioactive gases emitted by subsequent decays of naturally-occurring U and Th in dirt and rocks. (14) Fission releases a kinetic energy of about 1 MeV per nucleon, 200 MeV total. (15) The first physicist to suggest that the chemical elements were forged by nuclear processes in the cores of stars was Sir Arthur Eddington. When other physicists expressed skepticism, Sir Arthur would always reply, "Then why don't you go find a hotter place?" (16) The first physicist to realize that the universe must have started out in a very hot, extremely dense state (and to estimate a value of the Hubble constant before Edwin Hubble even discovered the expansion of the universe observationally) was Georges Lemaître. (17) Only about 4% of our universe consists of ordinary matter--- electrons, protons, neutrons (in nuclei), neutrinos and photons. (18) It's pretty much universally agreed now that the idea of supersymmetry is incorrect.
Course notes: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10. Notes for the last few weeks of the course are entirely on the web pages projected during the class lectures.