PHYSICS 362L - Rory Coker
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.

[C1] [C2] [S] [A] [OK] [F] [T] [KC] [T] [T2]

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:

  •  Particle Physics in the LHC Era, by G. Barr, R. Devenish, R. Walczak and T. Weidberg, Oxford, 2016.
  • Modern Particle Physics, by M. Thomson, Cambridge, 2013.
  •  Particle Physics, by D. Carlsmith, Pearson, 2013.
  •  Nuclear Physics in a Nutshell, by C. A. Bertulani, Princeton, 2007.
  • Basic Ideas and Concepts in Nuclear Physics, by K. Heyde, 3rd Ed., IOP London, 2004.
  •  An Introduction to Nuclear Physics, by W. N. Cottingham and D. A. Greenwood, 2nd Ed., Cambridge, 2001.
  •  Introductory Nuclear Physics, by P. E. Hodgson, E. Gadioli and E. Gadioli Erba, Oxford, 1997.
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    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.

    Here is a way to get extra credit!

    CLASS SLIDES FOR 362L: Accelerators & relativity, Diagrams, cross sections, Running coupling constants, Particles, Observing, Symmetry, Isospin, PCT, EM radiation, Weak 1, Gauge Symmetry, Electroweak1, Strong1, Supersymmetry? Quarkonium, Valence Quarks, FermiGas, IMP, Optical Model, Heavy ions, Direct Reactions, Mass Formula, Nuclear Vibrations, Nuclear Rotations, The Little Bang, Unstable Nuclei, Radiation, Power, Fusion, Stars, Evolution, Late Stages, Nucleosynthesis, Pioneers, Cosmology, The Big Flash! Dark Matter, Matter Origins, Dark Energy, Inflation, When Chiral Symmetry Breaks, Strings, Black Hole History, Black Hole Primer, Quantum Gravity? Loop Quantum Gravity, CDT-CS, Frontiers? [The remaining two links were not used in this class.] Unused 1, Unused 2


    CLASS SLIDES FOR 302L:  Relativity 1, Relativity 2, Twins! Length Contraction! Binding Energy, Einstein's Theory of Gravity, Quantum 1, Quantum 2, Atoms, Spin and Pauli Principle, Molecules and Solids, X rays and Lasers, Nuclear1, Nuclear2, Radiation, Fission and Fusion, The Sun, Particles! The Proton, Early Universe, THE DARK!


    Einstein

    No fairer destiny could be allotted to any physical theory, than that it should of itself point out the way to the introduction of a more comprehensive theory, in which it lives on as a limiting case. [From his 1920 book summarizing the Special and General Theories of Relativity]

    In Spring 2019, watch for the Pizza Seminar! ♣



    Coker's Homepage     ♥


    Bose

    Fermi

    Before I came to the conference, I was confused about this subject. Having listened to your lecture, I am still confused. But on a higher level.  [Fermi to a conference speaker.]

    Dirac

    The steady progress of physics requires for its theoretical formulation a mathematics which get continually more advanced. This is only natural and to be expected. What however was not expected by the scientific workers of the last century was the particular form that the line of advancement of mathematics would take, namely it was expected that mathematics would get more and more complicated, but would rest on a permanent basis of axioms and definitions, while actually the modern physical developments have required a mathematics that continually shifts its foundation and gets more abstract. Non-euclidean geometry and noncommutative algebra, which were at one time were considered to be purely fictions of the mind and pastimes of logical thinkers, have now been found to be very necessary for the description of general facts of the physical world. It seems likely that this process of increasing abstraction will continue in the future and that advance in physics is to be associated with continual modification and generalisation of the axioms at the base of mathematics rather than with a logical development of any one mathematical scheme on a fixed foundation. [Paper on Magnetic Monopoles (1931)]

    Feynman

    Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen. The quantum mechanical and relativity ideas are examples of this.

    Gell-Mann

    In our work, we are always between Scylla and Charybdis; we may fail to abstract enough, and miss important physics, or we may abstract too much and end up with fictitious objects in our models turning into real monsters that devour us.

    Weinberg

    I do not think it is possible really to understand the successes of science without understanding how hard it is [to do science]— how easy it is to be led astray, how difficult it is to know at any time what is the next thing to be done.
    Salam

    From time immemorial, man has desired to comprehend the complexity of nature in terms of as few elementary concepts as possible.

    Witten

    In Newton's day the problem was to write something which was correct --- he never had the problem of writing nonsense, but by the twentieth century we have a rich conceptual framework with relativity and quantum mechanics and so on. In this framework it's difficult to do things which are even internally coherent, much less correct. Actually, that's fortunate in the sense that it's one of the main tools we have in trying to make progress in physics. Physics has progressed to a domain where experiment is a little difficult... Nevertheless, the fact that we have a rich logical structure which constrains us a lot in terms of what is consistent, is one of the main reasons we are still able to make theoretical advances.




    Two Pb nuclei collide at 160 GeV per nucleon.