Readings for Physics 230B fall 2012 ================================================== ================================================== Note: The most recent reading appears first. Please always note the dates. ================================================== ================================================== Reading for meeting 19 Tuesday, Dec. 4 Handout by my office door. Also you may wish to review the reading from meeting 13: Gunion III: 263-282 P&S Secs. 16.1-16.4 The handout is better on a couple of points. It has sections from two different books. We will start with additional discussion of the stuff meeting 18 and then return to the BRST Ward identity topic. ================================================== Reading for meeting 18 Thursday Nov. 29 Zee: Chapters N.2, N.3, N.4 Nima Arkani-Hamed seminar http://student.physics.ucdavis.edu/kiskis/phy230b_11/nima_seminar.MP4 or on student /home/u4/kiskis/public_html/phy230b_11/nima_seminar.MP4 This is about 2.7GB. Lots of this is much more advanced material and is an unfinished story. I know very little about it, but I think is important work and that it would be good to try to get some feel for what's going on. So we will read, discuss, and struggle to understand a little. I expect that we will be able to discuss Zee, N2 and a little N.3 in class. N.3 and N.4 get increasingly difficult as one goes on. The Arkani-Hamed seminar gives a sense what the current research looks like. It's fairly accessible in the beginning but gets harder and harder. ================================================== Reading for meeting 17 Tuesday, Nov. 27 Gunion III: pages 323-350 The main new thing here is the role of the polarization vectors when there are gauge bosons in the initial or final states. Thus direct your attention mainly to the part from the middle of page 335 through the top of 343. ================================================== Reading for meeting 16 Tuesday, Nov. 20 Gunion III: pages 300-323 This is detailed calculational stuff. To get an initial feeling for why it is useful and important, you might want to skim at least the first part of pages 323-350 where it is used to speed calculation before you start the main reading on page 300. For both this meeting and the next, you may also want to look at Zee, Ch. N.2 and Srednicki, Chs. 50, 60, and 81. They cover similar material, but the notation is quite different. It's a bit of a project (which I have not yet done) to establish exactly what the translation dictionary is. There is also some related, but much more advanced material in Zee, N.3 and N.4. ================================================== Reading for meeting 15 Thursday, Nov. 15 Gunion III: pages 283-299 This is the discussion of techniques to make the calculation of the color factors for diagrams more efficient. ================================================== Reading for meeting 14 Tuesday, Nov. 13 P&S Subsection of Sec. 17.4 Jet Pair Production p. 568-573. At the start of this meeting, I might do a little recap. We have covered a great deal of material in our last few meetings. Try to do your own mental summary of what has happened, and bring your questions or comments. We will also discuss some practical calculations as described in the P&S reading above. This little reading is picked out of a larger phenomenological context. Try to focus on the calculations of the diagrams for fundamental QCD processes. To help a little, I offer the following comments. "Parton" is the word for a point-like constituent (part) of a hadron. We now understand partons to be quarks and gluons. You can just ignore the hats on the Mandelstam variables. The QCD analog of QED \alpha is \alpha_s = g^2/(4 \pi). ================================================== Reading for meeting 13 Thursday, Nov. 8 Gunion III: 263-282 P&S Secs. 16.1-16.4 Issues related to Gauge invariance, Ward identities, unitarily, the role of ghosts, and BRST symmetry, ================================================== Reading for meeting 12 Tuesday, Nov. 6 Gunion III: 212-262 This concentrates on getting the Feynman rules. We will deal with the unitarity issues and BRST next week. This is a too big block of material that does not naturally split up. Get as far into it as you can. Try to read at least 212-229 and 240-245. Note: It appears that Jack has changed notation so that c rather than f is now used for the Lie algebra structure constants. This is slightly confusing because c is also used for the ghost field. In the former case there are three group indices on the c and in the latter just one. Another note: If you do look at the pages 230-239 and want other perspectives on the development, you can try P&S Sec. 7.2 for a discussion of LSZ reduction. ================================================== Reading for meeting 11 Thursday, Nov. 1 Gunion III: 165-211 At this stage, you can just skim the "Appendix" in pages 189-202 to get the main point. Zee: VII.1 This is the path integral quantization and Fadeev-Popov for for non-abelian gauge fields. It's on of the main topics for the quarter. ================================================== Reading for meeting 10 Tuesday, Oct. 30 [Originally scheduled for Reading for meeting 9 Thursday, Oct. 25] P&S: Ch. 14 and 15 (Ch. 14 is a short, descriptive physics interlude/motivation.) Gunion III: 104-164 Zee: IV.5, Appendix B This is a lot of material about Lie groups and gauge invariance---especially nonabelian gauge invariance. You will benefit from starting this reading early. If you have not studied Lie groups previously, this is going to be hard to get through. It is not necessary to master all of it at once. You can use these readings as a reference and go back to them as needed. If you have made a thorough study of the rotation group SU(2) and its Lie algebra, i.e. the angular momentum algebra, then you are in pretty good shape on the group theory already, and you can concentrate on nonabelian gauge invariance. Almost all the group theory you really need is present in SU(2) or is a generalization of that without new concepts. You have probably absorbed by osmosis that nonabelian gauge invariance is a pillar of the standard model. In that case, the gauge group is the direct product SU(3)xSU(2)xU(1). If you have a decent familiarity with those three groups, you can prosper as a particle physicist ---so long as you have no aspirations to heavy theory. ================================================== Reading for meeting 8 Tuesday, Oct. 23 Zee: III.4 Gunion III: 165-170, 86-103 P&S: Sec. 9.4 Path integral quantization of abelian gauge theory. These are a warm-up. They illustrate the issues in the simpler abelian case before we move on to the much more subtle nonabelian case. ================================================== Reading for meeting 7 Thursday, Oct. 18 Zee: II.6, II.7, II.8 P&S: 5.4 5.5 Gunion II: 92-112 (Note the II not III.) Likely you already covered at least the Gunion version of this in 230A. The main things I want to focus upon are gauge invariance and the photon polarization sums. Also a little on crossing. The coverage of Compton scattering in P&S and Gunion is long and detailed. We are not going to get into it at that level of detail in class. However, a problem set will be more detailed. For class, pay attention primarily to the photon polarization sums and the check for gauge invariance. I think that you covered the process e+e- -> mu+mu- in 230A. I hope that included P&S Secs. 5.2-5.3 or their equivalent. If not, you should read those sections at your convenience. It's very nice physics. ================================================== Reading for meeting 6 Tuesday, Oct. 16 Zee: II.5 P&S: 9.5 Gunion III: 62-85 These extend path integral/functional methods to fermions. However, one might do well to just say functional methods. Fermion "path integrals" are not literal sums over paths in any simple or ordinary sense. To make this work nicely, Grassmann numbers are introduced. Like complex numbers, these are are abstract objects defined by their convenient algebraic properties. Like complex numbers, they make some book keeping and calculations easier and more automatic than they otherwise would be. I am not assigning Zee:II.1-II.4 because I think that it is stuff that you covered in 230A. ================================================== Reading for meeting 5 Thursday, Oct. 11 Zee: I.4, I.5, I.6, I.9 Here we take a break from formalism and read some nicely described physics relating particles, fields, and forces. ================================================== Reading for meeting 4 Tuesday, Oct. 9 Zee: IV.3, V.2 P&S: Sec. 9.3, 11.3, 11.4, 11.5 This covers analogies to statistical mechanics and classes of diagrams included in Z, W, and \Gamma, the Legendre transform of W. In these readings, just try to understand the part about what diagrams are generated by Z, W, and \Gamma and the role of \Gamma in determining the vacuum expectation value of the field and whether or not there is spontaneous symmetry breaking. Try to ignore the renormalization issues. In P&S Sec. 11.4, you can just skim or even skip the subsection on the linear sigma model. Zee V.2 has a little on the relation to finite temperature QFT and Hawking radiation to boot. ================================================== Reading for meeting 3 Thursday, Oct. 4 Zee: I.3 and I.7 Gunion III: p. 19-61 P&S: Sec. 9.2 Functional methods and path integrals for field theory. ================================================== Reading for meeting 2 Tuesday, Oct. 2 Zee: Secs. I.1 and I.2 Gunion III: p. 1-19 P&S: Sec. 9.1 This introduces the formalism of path integrals in the context of QM. This is equivalent to canonical quantization. Aside from the fact that the path integrals and functional methods are more elegant, it is also easier to handle non-Abelian gauge fields in the path integral approach. ==================================================