PHYSICS 362L - Rory Coker
Prof. Rory Coker
Office: PMA 8.312
Phone: (512) 471-5194 (not recommended)
Fax: (512) 471-9637 (not recommended)
Email: rory coker's civilian mail, coker's physics department mail

Office Hours:  Usual, Thur, 2 - 3 PM in PMA 8.312; also Tue, 3 to 4 PM, on days when there is a Pizza Seminar.

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

The Fall 2024 unique number is 56845; the class meets from 2 to 3 PM, MWF in PMA 5.126. The TA is Alex Leviyev, e-mail alexleviyev@utexas.edu

Text: SUBATOMIC PHYSICS, 3rd Edition, by Henley and Garcia (World Scientific, 2007, 2010). Errata for Ch. 6, and errata for Ch. 11.  [A free pdf version of the text can be found by searching "pdf version of subatomic physics by henley and garcia".]  And here is an introduction to the theory of scattering. An even briefer introduction. Highly recommended as a 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. A nice introduction to relativistic quantum field theory, which is NOT used in this course, is Quantum Field Theory as Simply as Possible, by A. Zee (Princeton University Press, 2023).

The Syllabus is posted on the Canvas page for this course; the TA has also chosen Canvas to handle homework submission and grading. Check here also.

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.
  • A Prelude to Quantum Field Theory, by J. Donoghue and L. Sorbo, Princeton, 2022).
    •
    People doing Subatomic research here at UT Austin!
    RUNNING TABLE OF HOMEWORK DUE DATES AND TIMES: HW 1, due Sept. 18.  HW 2, due Oct. 2. HW 3, due Oct. 25. HW 4, due  Nov. 1. HW 5+ 6, counts as 2 assignments, due Nov. 22
    [The in-class quizzes are attendance checks, but if you miss the question take that as a self-diagnosis of not keeping up in the course!]
    Answers to in-class quizzes:  (1) the Feynman diagram shown represents a physically impossible process.  Unlike a nucleus, atom or molecule, a fundamental point particle has no internal structure or internal states.  It cannot absorb a real photon, go along for a while excited, and eventually de-excite by emitting a real photon. (2) The Feynman diagram is for pair creation.  Since the photon is massless but must carry momentum, and the electron and positron each have a mass of 0.5 MeV and being two particles, could have total momentum zero, 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. (3) The width of the resonance peak is directly proportional to the inverse of the average lifetime Ï„, which is bad for particles with very, very short lifetimes since the "peak" might be so broad as to be indistinguishable from the normal background.  (4) For an energy eigenstate the variables r and t can always be separated and if you know that, it is instantly obvious by inspection that applying the unitary operator given has no effect other than to change t to t'... the symmetry involved is time translation.  (5) If 6 charge states exist, then 2T + 1 = 6 which gives T = 5/2.  (6) E, a polar vector, changes sign.  B, an axial vector, and Q, an additive quantum number, do not change sign.  (7) In a transition to 4+ from 6+ there is no parity change so the transition must be E.  The ΔJ is 2, so this is an E2 transition.  (8) The decay Ï€- to e- plus an anti-electron neutrino is semi-leptonic. There are a valence quark and antiquark to start with, and a lepton and anti-lepton to end with. Only two people in the class got this right.  (9) The Electroweak theory is a unified theory of all electromagnetic and weak processes.  (10) The interaction between two nucleons turns out to depend on literally everything it could possibly depend upon, and in very complex ways.  (11) Meyer and Jensen won the Nobel Prize for their independent discovery that adding a spin-orbit term to the central potential in the independent particle model explains the Magic Numbers.  (12) 174W displays a classic rotational spectrum. Do you understand why only even values of J are allowed?  (13) People in the US get 85% of their annual radiation dose from medical and dental diagnostic and therapeutic X and gamma rays, and radioactive noble gases released in indoor environments.  (14) The power output per unit mass of an average main sequence star is most comparable to that of the decaying corpse of an average-size mammal.  (15) Studies of the rotational inertia of several neutron stars indicates that their material is "stiff," other than that there is no real clue to the overall composition of these nonluminous "stars."  (16) If the general public has ever heard of Sakharov, it is as the winner of the Nobel Peace Prize in 1975, but he was also the designer of the Soviet H-bomb and the first Tokomak, as well as clarifying the conditions needed in the early universe to generate matter.

    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.

    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, Fermi Gas, 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, Neutron Stars, Nucleosynthesis, Pioneers, Cosmology, The Big Flash! Dark Matter, More, Matter Origins, Dark Energy, Inflation, When Chiral Symmetry Breaks, Strings, Black Hole History, Black Hole Primer, Unruh radiation, Quantum Gravity? Loop Quantum Gravity, CDT-CS, Nuclear Chemistry, Frontiers? [The remaining two links were not used in this class.] Unused 1, Unused 2

    This class is now using the Lectures Online recording system, although I got no notification. This system records the audio and video material presented in class for you to review after class. Links for the recordings will appear in the Lectures Online tab on the Canvas page for this class. You will find this tab along the left side navigation in Canvas. To review a recording, simply click on the Lectures Online navigation tab and follow the instructions presented to you on the page. Where no recent class has a full recording, this happens when the battery-powered classroom microphone has not been put back on charge by previous (mindless) users, and is completely dead.  The recorded lectures are not videos of the lecture. They have only the audio track, and  views of the specific document camera and computer images projected on screen during class. You can learn more about how to use the Lectures Online system at this link. You can find additional information about Lectures Online at this link.


    Here is a way to get extra credit!

    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 Fall 2024, 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.
    u