Physics 684 - Intro to high energy physics (Spring 2022)

Professor Jahred Adelman

jahred.adelman@niu.edu

Monday/Wednesday 12:30-1:45, La Tourette 201

Course Syllabus

Chapters 1-2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Chapter 10

Neutrinos and flavor physics

Homework

Griffiths 1.19, 2.1, 2.2, 2.5, 2.6, 2.7, 2.8 due Feb 9

Griffiths 3.3, 3.4, 3.6, 3.15, 3.16, 3.17, 3.25. Also: At the HERA collider, 27.5 GeV electrons collided head-on with 920 GeV protons. What was the center of mass energy? (Note that for some of these problems you might want to get familiar with the PDG) Due Feb 16

Griffiths 4.8, 4.10, 4.13, 4.29, 4.30, 4.38. Due Feb 23

Send me a proposed final paper topic no later than Feb 28

Griffiths 6.8, 6.12, 6.14 (use results of problem 6.9, which you don’t have to do, and focus on non-relativistic limit only) + 6.15. Also: if a 1 GeV muon neutrino is fired at a 1 m-thick block of iron-56 with density 7.87x10^3 kg/m3 and the average neutrino-nucleon cross section = 8x10^-39 cm^2, what is the probability that the neutrino interacts in the block? Due March 21

Griffiths 7.6,7.13,7.18,7.48,7.49 (use your answer to 6.8 for part e). Also, send me two additional things: 1) An outline of your presentation (can just be in an email, but it should be a complete outline). Looking for roughly one item per slide, and remember that a good rule of thumb is one slide per minute (remember, it’s a 20 minute presentation) AND 2) At least two references that you are going to use for material and/or background information and/or reading to prepare for your talk, NOT including the ones that are the main paper you are presenting. Also tell me what you are using them for. A good starting point is some references or links from that paper, however you can also use textbooks or other papers. Wikipedia doesn’t count! due March 30

Griffiths 8.17, 8.24.

Also, draw the lowest order QCD diagrams for pp->2 jets. Next, one important question for experimentalists: in what pT range are boosted topologies useful? For example, imagine a very high-pT, boosted W boson decaying to quarks. Show that the jet cone size containing the two quarks from its decay is roughly given by dR (really the cone diameter) roughly 2*mW / pT.
Finally, top quarks are typically pair produced at the LHC. As we will see, the top quarks decay before hadronizing to a W boson and a b quark. The experimental signature thus depends on the subsequent W boson decays. W bosons can decay to a charged lepton-neutrino pair or a quark-antiquark pair. They cannot decay back to a top quark. Using only this knowledge and basic information from QCD (don't calculate matrix elements!), find the leading order branching ratios for ttbar to decay a) to only quarks/anti-quarks (no leptons, called the "all-hadronic" final state) and b) to a final state with an electron and a muon (include anti-electrons and anti-muons in your accounting)
Due April 6

Griffiths 9.5,9.16,9.29,9.30,9.31 (for the last problem, you may want to use the results from problem 9.1, which you do not need to prove). Due April 20