Agenda

Course Plan

You may refer to the Winter 2020 course for a sense of the topics, level, and style of the course.

Written course notes are posted in links below. I am gradually combining these into typed notes here, but there may be a delay. You are especially encouraged to contribute if you are familiar with GitHub and LaTeX. 

• Course Notes from 2017 by Adam Green

• Course Notes from 2020

• Course Notes from 2022

• Ongoing Course Notes [current pdf]

Week 1: Introduction and Kinematics

Agenda

An extended discussion of some of the topics in this course are in this snapshot of our ongoing course notes.

• Tue, Apr 2: Course logistics. Feynman diagrams. The big picture. Natural units. Review of special relativity. 

• Thu, Apr 4: Special relativity and indices. On shell versus off shell particles. 

  • A good reference for upper/lower indices and special relativity are my Physics 17 notes.

Assignments

Due dates, links to the assignments, and a submission link.

• Apr 4: Please review the course syllabus. [No submission]

• Apr 4: Pre-Class Survey (5 mins)

• Apr 4: 5-minute introductory video. [Submit Here]

  • Example: Prof. Tanedo's video

• Apr 4: Short Homework 1. [Submit Here]

  • Natural Units

  • Reminder to do Pre-Class Survey and Intro Video.

• Apr 11: Long Homework 1. [Submit here]

  • Natural units refresher

  • Special relativity in 4-vector notation, kinematics

  • Gaussian Integrals; you may find the notes from Physics 231: Week 8 (2023) useful if you get stuck. 

  • April 8: Corrected problems 4.3 and 4.5 so that the source terms are linear in the integration variable. 

Learning Objectives

• Interpret the meaning of a Feynman diagram as a spacetime history. Draw basic diagrams from Feynman rules. Basic observations about conservation laws.

• Convert between SI and natural units by "multiplying by one." Write all quantities in units of GeV to some power.

• Describe special relativity using 4-vectors. 

  • Convert between vectors (upper index) and covectors (lower index) using the metric tensor.

  • Perform Lorentz transformations on a generic tensor.

  • Use summation convention for tensor contractions.

• Kinematics: apply 4-momentum conservation and on shell conditions to the initial and final states of a diagram. Identify when a particle is off shell ("unphysical"). 

  • Demonstrate that the kinematic constraints on a process are Lorentz-invariant: a process allowed in one reference frame is allowed in any other valid reference frame. 

References, suggested reading

• Here's the snapshot of our ongoing course notes. I strongly encourage you to review Chapter 3.

• There is are decent introductions to special relativity in four-vector notation in Goldberg's The Standard Model in a Nutshell and Cottingham & Greenwood's an Introduction to the Standard Model of Particle Physics. 

• Larkoski 1.4, 2.1

• Feynman, QED ch. 2-3

• Additional references:

  • "Dimensional analysis, falling bodies, and the fine art of not solving differential equations," Craig Bohren. American Journal of Physics 72, 534 (2004); https://doi.org/10.1119/1.1574042 (access through UCR VPN)This article really captures the spirit of this course and is a non-trivial demonstration of the power of dimensional analysis. It gives us a reason to pause and think about what it means for our idealized models of nature to be reasonable approximations to the complex reality around us.

  • "Natural Units and the Scales of Fundamental Physics," Robert Jaffe, Supplementary Notes for MIT’s Quantum Theory Sequence, Feb 2017. Jaffe's notes have plenty of examples of dimensional analysis as well as a thorough introduction to natural units.

  • Particle Fever is a documentary about the quest to discover the Higgs Boson. You may want to watch it as teaser for our course. It is available for streaming through UCR.

Miscellaneous

Particle physicists have a tradition of writing April Fool's papers. Here's a "Feynman diagram" from one such April Fool's paper (2404.00690), whose title pokes fun at the "scotogenic" neutrino mass model developed at UC Riverside by Professor Emeritus Ernest Ma. 

Another very good April Fool's paper this year is a proposal to solve the Hubble tension by allowing the value of pi to be fit: 2403.20219. 

Week 2: Dynamics of QED

Agenda

• Tue, Apr 8: Quantum mechanics done properly. The double slit experiment. Introduction to the path integral formalism: why each path is weighted by the action. Introduction to QED diagrams. We skipped: "deriving" the Schrodinger equation from the path integral. I typed up the argument carefully here.

• Thu, Apr 10: Introduction to field theory. A hint at the mathematics behind Feynman diagrams. Gaussian integrals. Because today's lecture is a little equation-heavy, please see these hand-written notes so you do not have to worry about copying things down. Note: you are not responsible for re-deriving any of the technical work today: this is the mathematical scaffolding to justify our diagrammatic approach.

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

Due dates, links to the assignments, and a submission link.

• Apr 11: Long Homework 1. [Submit here]

  • Natural units refresher

  • Special relativity in 4-vector notation, kinematics

  • Gaussian Integrals; you may find the notes from Physics 231: Week 8 (2023) useful if you get stuck. 

  • April 8: Corrected problems 4.3 and 4.5 so that the source terms are linear in the integration variable. 

• Apr 18: Explainer Video 1.  [submit]

  • Your assignments are posted on our internal sheet, please email Prof. Tanedo (with a subject that includes "[P165]") if you do not have access to that page. 

Miscellaneous

• You may enjoy this recent song about the B-meson, which relies on the slant rhyme between "B-meson" and "beam is on."

• Peter Higgs' death was announced shortly after our class on Tuesday.  

Week 3: Field Theory Primer 

Agenda

• Tue, Apr 16: Feynman diagrams as Green's functions in field theory. Refresher on Fourier series, Fourier transform as changes of basis. Treating nonlinear terms using perturbation theory: vertices in Feynman diagrams. Sketch of Fourier notes.

• Thu, Apr 18: From Gaussian integrals to propagators, notes (not really notes, just the equations that we wrote on the board). Interacting scalar field theory summary.

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

Due dates, links to the assignments, and a submission link:

• Apr 23: Short Homework 2. [Submit here] Updated 4/18: My apologies, the original version of this problem had some absolute nonsense (link to old, wrong version). Thank you Daniel B. for catching this nonses. I have updated the problem to be a bit more direct and have extended the due date to Tuesday so we may discuss if needed. Update 2: this is short homework #2. Update 4/23: link fixed, thanks Daniel C.

• Apr 18: Explainer Video 1.  [Submit here]

  • Your assignments are posted on our internal sheet, please email Prof. Tanedo (with a subject that includes "[P165]") if you do not have access to that page.  

• April 25: Long Homework 2 [Submit here]: full homework to be posted soon (problem 4 is being rewritten)

Additional Reading

• A great visual exploration of Gaussian processes, in case you wanted to see how Gaussians show up in machine learning.

Week 4: Electroweak Theory 

Agenda

• Lec 7, Tue, Apr 23: The rules of QCD and electroweak theory. Introduction to indices.

• Lec 8, Thu, Apr 25: Indexology for Lagrangians. Notes.

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

Due dates, links to the assignments, and a submission link:

• Apr 23: Short Homework 2. [Submit here] Updated 4/18: My apologies, the original version of this problem had some absolute nonsense (link to old, wrong version). Thank you Daniel B. for catching this nonses. I have updated the problem to be a bit more direct and have extended the due date to Tuesday so we may discuss if needed. Update 2: this is short homework #2

• Apr 25: Peer Review 1.  [Submit here]

  • You have been assigned three peers, your job is to review their videos. These assignments, links to the videos, and a link to their PDF work are posted on our internal sheet.

  • You do not have to review the PDF, but it may be helpful. 

  • The guidelines for the numerical scoring are on our rubric. Give honest and fair scores.

  • Please email a copy of your one paragraph review to the peer you are reviewing. 

  • If your peer does not have a video posted, please email them (you may cc Prof. Tanedo) reminding them to post their video.

  • Your assignments are posted on our internal sheet, please email Prof. Tanedo (with a subject that includes "[P165]") if you do not have access to that page.  

• April 25: Long Homework 2 [Submit here]: because I messed up the short homework, I have removed Problem 4 (which was incomplete anyway).

Additional Reading

• A great visual exploration of Gaussian processes, in case you wanted to see how Gaussians show up in machine learning.

Week 6: Indices Again

Agenda

• Lec 11, Tue, May 7: those damn spinor indices

• Lec 12, Thu, May 9: No class. I will be serving at the HEPAP meeting; the contents of which are tangentially related to our course. (Presentations are posted, videos coming soon.) Please see the following recorded lecture and notes in lieu of our in class meeting:

  • Lec 12 makeup lecture (1:30, recorded in one cut while waiting for a flight)

  • PDF of Lec 12 makeup notes

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

Due dates, links to the assignments, and a submission link:

• Thu, May 9: Long Homework 3 [Submission link]

Additional Reading

Week 7: Indices Again

• Lec 13: The Lagrangian for the Standard Model

• Lec 14: Electroweak symmetry breaking (recording, sorry no lecture notes; recordings are deleted in 20 days)

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

Due dates, links to the assignments, and a submission link:

• Thu, May 16: Short Homework 4 [submission link]

• Thu, May 23: Long Homework 4 [Submission link]

• Explainers and peer reviews to be posted (none due this week)

• Present-a-Plot topics

Week 8: Symmetry Breaking

• Lec 15: Mass terms and Goldstone Bosons

• Lec 16: No lecture. Recorded make up lectures:

  • Lec 16a: W and Z mass

  • Lec 16b: Goldstone Bosons

  • Lec 16c: electric charges of the fermions

  • Written notes for these lectures.

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

• PERTS survey2: https://perts.me/MPYK

• Present-a-Plot topics (please sign up)

• Short HW 5 (submission link)

• Long Homework 5 (submission link)

Week 9: Flavor

Zoom link for those who are away.

• Lec 17: Review, Yukawas. Recording (link expires in 20 days)

• Lec 18: Flavor-changing interactions of the W. Renormalizability, a first pass. Recording (link expires in 20 days)

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

• PERTS survey2: https://perts.me/MPYK

• Present-a-Plot topics (please sign up)

• Thursday May 30: Short HW 5 (submission link)

• Friday, June 7: Long Homework 5 (submission link)

Reading

• "Do charged leptons oscillate?" Akhmedov (arXiv:0706.1216)

Week 10: Effective Field Theory, hint of renormalization, dark matter

Zoom link for those who are away.

• Lec 19: Some snapshots of effective field theory (recording, up for 20 days)

• Lec 20: Open questions in particle physics

Assignments

Our course internal sheet is here. This is only accessible to other members of our class and contains your explainer video and peer review assignments.

• PERTS survey 3: https://perts.me/MPYK

• Present-a-Plot topics (please sign up)

• Friday, June 7: Long Homework 5 (submission link)

• No more peer reviews or explainer videos.

Reading

• "The eighteen arbitrary parameters of the Standard Model in your everyday life." Robert Cahn (1996). Now that we've reviewed the Standard Model, you should think about how many free parameters there are, and what the universe would have looked like if they were different.

• BobbyBroccoli has a series of three mini-documentaries on the Super Conducting Supercollider (SSC), the failed American 40 TeV collider. Part 1, Part 2, Part 3. It is a fascinating take on the recent history of particle physics in the United States.

  • The documentaries draw on the definitive book on the topic, Tunnel Visions. You can find a couple of colloquia by the authors here and here.

  • If you want to learn more about the future of particle physics, you should learn about the ongoing Snowmass 2021 process. You can find highlights from the theoretical physics frontier here

• "Regularization, renormalization, and dimensional analysis: Dimensional regularization meets freshman E&M," Fredrick Olness and Randall Scalise
  American Journal of Physics 79, 306 (2011); https://doi.org/10.1119/1.3535586

  • This is an excellent introduction to the ideas of renormalization applied to a system that has nothing to do with quantum field theory. The article will seem a little strange: it asks questions in a way that is not common in your electrodynamics courses because it approaches this familiar topic using the methods that we use in quantum field theory.

• John Baez's post on renormalizability (2006) and renormalization (2009); and a bit on the Callan-Symanzik equation

• One of my favorite descriptions of renormalization and the relation to dimensional analysis is "Dimensional Analysis in Field Theory" by Stevenson

• Popular description of renormalization by Charlie Wood in Quanta magazine.

• A nice description of renormalization from ZAP Physics on YouTube; though I warn that the point of renormalization is not to "deal with infinities." Those infinites were never physical to begin with. Renormalization is the idea that the "best" perturbative description of a quantum field theory changes depending on the scale at which you are testing the theory.

Finals Week: Explain-A-Plot

Our final exam slot is Friday June 14, 8-11am. We will only use two hours of this slot, so we shall begin at 9am at our usual classroom. 

You will have 5 minutes to briefly present the big picture idea of an experiment, draw a relevant Feynman diagram, and explain a plot (projected onto the board) to the class. 

To do:

• Present-a-Plot topics (please sign up if you haven't already)

• [Submission link] By Wed, June 12, please upload a pdf/image of the one plot you would like to present. 

• PERTS survey 3: https://perts.me/MPYK

How this works

• You will have five minutes + a bit of time for questions.

• Your talk should answer:

  • What is the experiment trying to measure?

  • Why is it trying to measure that? (What do we learn)

  • How does it work? (briefly)

• You should draw one Feynman diagram showing the underlying interaction at the experiment.

• Present one plot showing results or expected results:

  • Start by explaining what the x- and y-axes are

  • Explain what is being plotted and any features (bumps, wiggles, dots)

  • Explain what the lines mean: what happens if you are above the line? What happens below the line? If the experiment is excluding a possibility, which possibilities are excluded?

Guidelines

• "The eighteen arbitrary parameters of the Standard Model in your everyday life." Robert Cahn (1996). Now that we've reviewed the Standard Model, you should think about how many free parameters there are, and what the universe would have looked like if they were different.

• BobbyBroccoli has a series of three mini-documentaries on the Super Conducting Supercollider (SSC), the failed American 40 TeV collider. Part 1, Part 2, Part 3. It is a fascinating take on the recent history of particle physics in the United States.

  • The documentaries draw on the definitive book on the topic, Tunnel Visions. You can find a couple of colloquia by the authors here and here.

  • If you want to learn more about the future of particle physics, you should learn about the ongoing Snowmass 2021 process. You can find highlights from the theoretical physics frontier here

• "Regularization, renormalization, and dimensional analysis: Dimensional regularization meets freshman E&M," Fredrick Olness and Randall Scalise
  American Journal of Physics 79, 306 (2011); https://doi.org/10.1119/1.3535586

  • This is an excellent introduction to the ideas of renormalization applied to a system that has nothing to do with quantum field theory. The article will seem a little strange: it asks questions in a way that is not common in your electrodynamics courses because it approaches this familiar topic using the methods that we use in quantum field theory.

• John Baez's post on renormalizability (2006) and renormalization (2009); and a bit on the Callan-Symanzik equation

• One of my favorite descriptions of renormalization and the relation to dimensional analysis is "Dimensional Analysis in Field Theory" by Stevenson

• Popular description of renormalization by Charlie Wood in Quanta magazine.

• A nice description of renormalization from ZAP Physics on YouTube; though I warn that the point of renormalization is not to "deal with infinities." Those infinites were never physical to begin with. Renormalization is the idea that the "best" perturbative description of a quantum field theory changes depending on the scale at which you are testing the theory.

Miscellaneous end of quarter stuff

• There were a few questions about string theory at the end of our class. It just so happens that the Strings 2024 workshop just wrapped up at CERN and you may enjoy the following closing remarks about the status and future of string theory by Prof. Hiroshi Ooguri.