Course syllabus

Course-PM

Standard model of particle physics

TIF355 / FYM355   (Chalmers U./Gothenburg U.)  lp1 HT21 (7.5 hp) 

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BOOK THE ORAL EXAM HERE

Welcome to the course!

Zoom ling for the "regular" lectures:

https://chalmers.zoom.us/j/68209608382

Password: 865400

(stay tuned for more chances to meet...)

My (schematic) notes...

Non-abelian gauge symmetry and QCD

Spontaneous symmetry breaking

Spinors and chirality

Standard Model Lagrangian

Colliders and detectors

Feynman rules of the Standard Model

DY PDF DIS

W Z and top

Higgs

Contact details

Examiner/lecturer:  Gabriele Ferretti  (ferretti@chalmers.se)

Under normal circumstances can be found in Origo room 6111. Tel. 031-772 3157.

Student representatives:

MPPHS	marberti@student.chalmers.se	Markus Bertilsson
MPPHS	habagil@student.chalmers.se	Ben Habagil
UTBYTE	m.jasper.martins@gmail.com	Michael Jasper Martins
MPPHS	aranciohr@gmail.com	        Carl Henrik Rohdin
MPPHS	johwiks@student.chalmers.se	Johan Wikström

Prerequisites (important!)

The prerequisites for this course are any introductory course in quantum field theory where

1- you have seen the QED lagrangian

\(-\frac{1}{4} F_{\mu\nu} F^{\mu\nu} + \bar\psi (i \gamma^\mu D_\mu - m)\psi\) 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ 1 4 F μ ν F μ ν + ψ ¯ ( i γ μ μ m ) ψ

2- you have derived its Feynman rules and

3- you have computed at least one elementary process, e.g. the Möller scattering  cross section for

\(e^-\, e^- \to e^- \, e^-\) e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e

Being familiar with this "chain of thought" (Lagrangian --> Feynman diagrams --> Observable quantities) is very important because then you can appreciate directly from the Standard Model lagrangian what kind of physical phenomena to expect.

I will not forbid you to take this course if you are not familiar with the above but you must then make an additional effort to cover that. I will help you (contact me) and guide you through some of the expository material below that covers this subject.

Course purpose

The aim of the course is to present the Standard Model of particle physics, which is a relativistic quantum field theory describing how the known elementary particles interact via the electromagnetic, weak and strong force. A key element in this theory is the Higgs mechanism, and the associated Higgs particle recently discovered at the LHC experiments at CERN.
The purpose of the course is to provide the students with a working knowledge of the basic concepts and features of the Standard Model, including its predictions with focus on hadron colliders. The students will also gain some insight on various proposals for what theory may lie beyond the Standard Model and how such proposals are currently being searched for experimentally.

Course literature

The course content consist of the material in the videos below. I will also post a scan of my lecture notes so you can  keep track of where we are.  Additional material can be found in the following three freely available lecture notes, which I will help you navigate:

From quantum mechanics to the standard model by B. Gripaios.

Standard Model: An Introduction by S.F. Novaes.

Some slightly more advanced lectures:

Introduction to the Standard Model by L. Gibbons.

Collider Physics within the Standard Model by G. Altarelli.

Groundbreaking theory papers: (Can be downloaded if you have a Chalmers IP)
Yang-Mills theory   by Chen-Ning Yang and Robert Mills (where non-abelian gauge symmetry was born).
A Model of Leptons  by Steven Weinberg (where the Standard Model was born).
Broken symmetry and the mass of gauge vector mesons by Robert Brout and François Englert and
Broken symmetries and the masses of gauge bosons by Peter Higgs (where the "Brout-Englert-Higgs" mechanism and the Higgs boson were born. Look also at  Global Conservation Laws and Massless Particles by G. S. Guralnik, C. R. Hagen, and T. W. B. Kibble).
CP-violation in the renormalizable theory of weak interactions, by Makoto Kobayashi and Toshihide Maskawa (where the CKM matrix is introduced. Look also at  Unitary Symmetry and Leptonic Decays by Nicola Cabibbo)
Groundbreaking experimental papers:
Discovery of the W boson at CERN, UA1 experiment UA2 experiment
Discovery of the Z boson at CERN, UA1 experiment UA2 experiment
Discovery of the top quark at Fermilab, CDF experiment D0 experiment
Discovery of the Higgs boson at CERN, ATLAS experiment CMS experiment
Some QFT Textbooks I like:
1) Srednicki's book Quantum Field Theory (which is available for free online!),
2) Peskin & Schroeder's book An introduction to Quantum Field Theory
4) Martin and Shaw's Particle Physics

Course design

We will have regular lectures at the scheduled time, if possible in class, otherwise online. Depending on how easy you find following the other online material, we will use part of the lecture time to discuss further questions you may have.

Changes since the last occasion:

(to be added... Hopefully additional chances to meet!)

Learning objectives

- Acquiring the prerequisite theoretical tools for the construction of models of particle physics. 

- Understand the underlying principles and structure of the Standard Model of particle physics, with particular emphasis on the Higgs mechanism and the properties of the Higgs boson. 

- Work out basic predictions of the Standard Model and compare them with experimental data.  

Syllabus

Once you have the prerequisite of elementary QED (see prerequisites above), to construct the Standard Model you need to acquire three more theory tools. We start with a discussion of each one of them separately, in a simpler setting. They are I) Non abelian gauge invariance, II) Spontaneous symmetry breaking and III) Chirality. 

I) Non abelian gauge invariance and some Lie algebra.

I made a bunch of videos to introduce the concept of gauge invariance, starting with a reminder of the abelian case. It's overcomplete... Skip freely the material that is already familiar to you:

Plane electromagnetic wave 

Coupling the electromagnetic field to matter

From abelian to non-abelian symmetry. U(1), U(n), SU(n) groups and Lie algebras.

 Generators of the Lie algebra SU(n).

SU(2), SU(3), Pauli and Gell-Mann matrices.

More on representations of SU(3)

 Need for a covariant derivative

The covariant derivative of QCD

Gluon field strength.

The QCD Lagrangian and Feynman rules.

II) Spontaneous symmetry breaking. Global vs. Gauge symmetry

Here are some lectures reminding you the basics of symmetry breaking. Again, skip if you know this. Make sure you understand the difference between discrete/continuous, global/gauged, broken/unbroken symmetries. 

Introduction

Interlude: Comparing classical mech. quantum mech. and QFT.

Breaking of a global symmetry

Gauge U(1) symmetry.

Interlude: Meaning of a mass term for the gauge field.

Summary

III) Chiral spinors.

And now a few videos on chirality. I just focus on the parts that are relevant for the construction of the Standard Model lagrangian. You could look up additional material in one of the refs above (or your favorite QFT source).

 Representations of the Lorentz group

Spinor representations. Left and right handed components.

The Dirac Lagrangian and the coupling to gauge fields.

And now we are ready to: 

IV) Construct the Standard Model

- The Standard Model. 
- The Higgs mechanism, W and Z Masses.
- Fermion masses
- The currents, coupling of vector bosons to fermions, CKM matrix, Neutral currents. 
My own take on this is recorded in the videos below. First we show how to construct all the possible terms in the lagrangian, then how to read off the spectrum and the interactions.
We start with the table of fields and quantum numbers (but listen to the beginning remarks!) 

Meet the Standard Model!

Some clarifications about the field content

The lagrangian for the gauge bosons.

The kinetic term lagrangian for the fermions.

The Higgs lagrangian

Interlude on effective field theory

The Yukawa couplings

Finishing the Yukawa couplings

 

Now we have all the terms and are ready to study the spectrum and the interactions:

 

General strategy for computing the spectrum and the couplings

Minimizing the Higgs potential

Gauge boson masses.

A first look at the fermion masses

Interlude: Difference between fermion and boson mass matrices.

Back to fermion masses.

The fermion kinetic term.

Currents in the mass eigenbasis.

Interlude: Properties of the fermi-fermi-vector interactions.

More informal discussion on fermi-fermi-vector interaction.

A closer look at the CKM matrix.

Simplifying the CKM matrix.

The EW gauge boson couplings.

Higgs couplings.

Higgs couplings with the other particles.

 

But how do we know it's right? Well... let's take a (metaphorical) step into the lab:
V) Predictions and tests of the Standard Model.
- Types of colliders, advantages and disadvantages. Luminosity, CM energy. 
- W and Z physics. 
- top quark physics.
- Higgs physics. 

Examination form

The examination consists of four or five mandatory homework sets and an optional oral examination. The homework sets count for the passing grade and the oral examination counts for the higher grades.
If you are happy with just a passing grade you do not need to take the oral exam. If you take the exam, your grade will not go down, that is, you have a guaranteed "3 (CTH) or G (GU)" if you have done all the homework.
The homework sets will be posted during the course duration. There will be a suggested deadline, but I do not intend to enforce any penalty if you miss it. It's just for your own convenience of keeping up with the subject. Each homework is graded pass/fail. You may need to redo some parts of the homework set to pass. To pass the course or be allowed to take the oral exam you need to have passed all homework sets.
The oral examination will be a c.a. 45 min discussion.
We begin with you presenting a subject of your choice related to the course in 10 min. sharp. Then move on discussing the material of the course.
 
See you soon!
Gabriele

Course summary:

Date Details Due