This is an introduction to elementary particle physics, often referred to as high- energy physics. This is a study of the fundamental constituents of matter and the forces that dictate their quantum mechanical interactions. Our theory for this field is called the Standard Model and in this class we will understand its theoretical scaffolding, experimental discovery, and phenomenological consequences. (4 units)

Pre-requisites: special relativity
Co-requisites: quantum mechanics

Lecturer: Prof. Flip Tanedo ( )
TA: Ian Chaffey ( )

Lec: TR 5:10 - 6:30pm in Physics 2014
Dis: R 6:40 - 7:30pm in Physics 2014
Final: Sat, March 17; 7:00 - 10:00pm
Midterm: In-class presentation, weeks 5-6

Syllabus: pdf

Notes: handwritten lecture notes lecture , typed course notes course

Weekly is due in class on Tuesday. Short assignments are assigned on Tuesday and due in class on Thursday. Homework page on GitHub: homework .

Each student is responsible for an in-class, 5-minute presentation about a figure or plot related to particle physics. These will be held starting in week 6. You are encouraged consult with Prof. Tanedo before your presentation to make sure you’ve understood everything.

Guidelines

• Start by describing what you’re supposed to learn from the plot.
• In a few sentences, briefly explain the experimental set up. Example: “They smash electrons and positrons together over and over again, then they record the invariant mass of any muon–anti-muon pairs.”
• Explain the x- and y-axes: what do they measure, what units.
• Explain what features in the plot mean.

Plots

We will have sign ups in class, you may sign up any of the list below (one person per plot) or propose another plot based on the references for the class or from your own reading. Anything that’s crossed out has already been presented.

• You may choose anything from the “Plain English Summaries of D0 publications,” or the Run II version of the same program.

• NOvA’s first neutrino, K. Jepsen Symmetry Magazine, (05/06/14). symmetry

• Ultra-high-energy neutrinos, K. Tuttle Symmetry Magazine, (11/08/13). symmetry You may need to do some additional research to find a good plot.

• OPERA’s first tau neutrino, R. Antolini, Symmetry Magazine, (02/01/11). symmetry

• Neutrino oscillation, K. Riesselmann Symmetry Magazine, (02/01/10). symmetry

• Weak neutral current, K. Riesselmann Symmetry Magazine, (08/01/09). symmetry

• LHC Startup, K. Riesselmann Symmetry Magazine, (01/01/08). symmetry

• Z boson, D. Harris Symmetry Magazine, (08/01/08). symmetry

• CMS cosmic challenge, K. Riesselmann Symmetry Magazine, (12/01/07). symmetry

• First vertex detector, K. Zala Symmetry Magazine, (07/01/06). symmetry

• J/$\Psi$ particle, M. Bobra Symmetry Magazine, (09/01/05). symmetry

Plots, Set 2

• Historical perspective of values of a few particle properties, PDG 2016. pdf
• Brazil Plots, T. Dorigo for AVMA4NewPhysics Blog. blog
• Three Neutrino Families, S. Hossenfelder for Backreaction Blog. blog
• Higgs Discovery: The Data, M. Strassler, Of Particular Significance, 6 July 2012. blog
• A Moriond Retrospective: New Results from the LHC Experiments, Julia Gonski, Newsletter of the EP Department (CERN), 27 June 2017. (Any plot.) blog
• Studying the Higgs via Top Quark Couplings, Julia Gonski, ParticleBites, 15 November 2016. blog
• What Happens When Energy Goes Missing?, Julia Gonski, ParticleBites, 29 October 2016. blog
• Electroweak interference confirmed, Bertram M. Schwarzschild, Physics Today 35, 8, 19 (1982) doi
• Proton decay not seen at predicted rate, Bertram M. Schwarzschild, Physics Today 36, 9, 20 (1983) doi
• The top quark, 20 years after its discovery, Dmitri Denisov and Costas Vellidis, Physics Today 68, 4, 46 (2015) (any plot) doi

Handwritten lecture notes lecture , typed course notes course

Extra notes for this week: Extra

This week we went over the course syllabus pdf and did a lightning review of special relativity (Tue) and quantum mechanics (Thu). We focused on the following key points:

• We work in natural units.
• Energy and momentum are conserved.
• Quantum mechanics: what we learn from the double slit experiment.
• A model is a list of particles (lines) and rules for how they interact (vertices).
• Feynman rules of QED and its variants.

Natural units

You may find the Jaffe’s Supplementary Notes for MIT’s Quantum Theory Sequence: Natural Units useful.

More reading about special relativity

You should have a solid background in special relativity. In the coming weeks we’ll be using ideas about how four-vectors transform and what types of objects do not transform. Those looking for a refresher may consult the following references as needed (free access through UCR library):

• Chapter 1 (Special Relativity) of From Special Relativity to Feynman Diagrams by D’Auria and Trigiante; Springer Scotty
• Special Relativity: A Heuristic Approach, Sadri Hassani Springer Scotty

More reading about Feynman diagrams

The core ideas of how to draw Feynman diagrams can be found in the following popular-level accounts:

• “Teaching Electron—Positron—Photon Interactions with Hands-on Feynman Diagrams”, Kontokostas and Kalkanis, The Physics Teacher 51, 232 (2013) doi .
• “Feynman Diagrams: Particle Skribblings with a Serious Meaning” in Quirky Quarks by Bahr, Lemmer, Piccolo. Scotty Springer

Handwritten lecture notes lecture , typed course notes course

This week we went over the rules of simple QED-like theories. We familiarized ourselves with how to draw and interpret Feynman diagrams and how to apply kinematic rules to a diagram to understand the four-momentum flow. We started to generalize our notion of vectors to work with four-vectors and manipulate indices. Some highlights:

• A model’s vertices tell us about its conservation laws.
• An object’s indices tells you how it transforms.
• Contraction: repeated indices are summed over.
• A metric raises/lowers indices.
• An object with no indices is an invariant.

Tensor analysis

More references: (free access through UCR library or the web):

• Tensors for Physics by S. Hess; Springer Scotty
• Quick Introduction to Tensor Analysis by Sharipov arXiv
• The distilled version can be found in these selected lectures from Physics 231 (2017) pdf . The content of those lectures is a bit more than we need in our class, but flesh out some of the structure that we’ve swept under the rug.
• See also John Peacock’s lectures on mathematical physics pdf .

My favorite relativity book is Sander Bais’ Very Special Relativity Scotty, though this is unfortunately not available digitally through our library.

More advanced tensor analysis

• “Tensors: A guide for undergraduate students,” F. Battaglia, American Journal of Physics 81, 498 (2013).
• “Foundations of Tensor Analysis for Students of Physics and Engineering With an Introduction to the Theory of Relativity,” Kolecki. NASA/TP—2005-213115. Scotty NASA

Spinors

For an introductory mathematical treatment of spinors, see “An introduction to spinors” by Steane arXiv.

Handwritten lecture notes lecture , typed course notes course

This week we re-introduced QED and learned about the tensors of the Lorentz group and then reviewed the main symmetries that we’ll need for the Standard Model.

Additional resources:

• Physics 231 (2017) notes on tensors, part 1. pdf
• Physics 231 (2017) notes on tensors, part 2. pdf
• See also the references from Week 2.

Handwritten lecture notes lecture , typed course notes course

This week we developed the electroweak leptonic sector and then learned how the Higgs breaks electroweak and chiral symmetry.

Useful references:

• “The Unification of Electromagnetism with the Weak Force,” P. Langacker and A.K. Mann, Physics Today 42, 12, 22 (1989); doi
• “Conservation Laws, Symmetries, and Elementary Particles,” Hoekzema, Schooten, van den Berg, and Lijnse, The Physics Teacher 43, 266 (2005) doi

Additional resources:

• Advanced notes about the “spin” representations of particles pdf

Handwritten lecture notes lecture , typed course notes course

This week we wrapped up our cursory view of electroweak/chiral symmetry breaking by arguing why the Higgs vacuum expectation value can “give mass” to fermions and gauge bosons. In lecture 10 we started a new approach to understand this phenomena more rigorously by introducing field theory.

Useful references:

• “Action physics,” Lachlan P. McGinness, and C. M. Savage, American Journal of Physics 84, 704 (2016) doi

• “Teaching Feynman’s sum-over-paths quantum theory,” Edwin F. Taylor, Stamatis Vokos, John M. O’Meara, and Nora S. Thornber; Computers in Physics 12, 190 (1998); doi

• “Conservation Laws, Symmetries, and Elementary Particles,” Hoekzema, Schooten, van den Berg, and Lijnse, The Physics Teacher 43, 266 (2005) doi

• “The development of field theory in the last 50 years,” Victor Weisskopf, Physics Today 34, 11, 69 (1981); doi

• “There are no particles, there are only fields,” Art Hobson American Journal of Physics 81, 211 (2013) doi

Additional resources:

• “Second quantization in nonrelativistic quantum mechanics,” Donald H. Kobe American Journal of Physics 51, 312 (1983); doi

• “The calculated photon: Visualization of a quantum field,” Martin Ligare, and Ryan Oliveri American Journal of Physics 70, 58 (2002); doi

Lecture Notes: to be posted as the course progresses.

This course is part of the UCR Affordable Course Materials Initiative so that the total material cost to students is zero.

Online materials are available through the UCR Library and can be accessed off-campus using the VPN.

Primary References

• The Particle Data Booklet from the Particle Data Group. The PDG has provided booklets for our class. All material is also available online.

• Introduction to Elementary Particle Phenomenology, Philip Ratcliffe. Available online with UCR credentials.

• Concepts of Elementary Particle Physics, lecture notes (soon to be a book) by Michael Peskin. Available online.

• Particle Physics: A Los Alamos Primer, ed. Necia Grant Cooper and Geoffrey B. West (Los Alamos National Library). online

• Introduction to Elementary Particles: Lecture Notes, Juan Rojo (2018). online, pdf

Secondary Texts

Additional readings will be assigned as the course progresses. All readings will be accessible online through the UCR library.