Course-PM

Standard model of particle physics

TIF355 / FYM355   (Chalmers U./Gothenburg U.)  lp1 HT20 (7.5 hp) 

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Welcome to the course!

https://chalmers.zoom.us/j/65260511684
Password: 336169

On dates: (as communicated in my email).

week 36
Tue 2020-09-01

week 37
Tue 2020-09-08
Thur 2020-09-10

week 38
Tue 2020-09-15

week 39
Tue 2020-09-22
Thur 2020-09-24

week 40
Tue 2020-09-29
Thur 2020-10-01

week 41
Tue 2020-10-06
Thur 2020-10-08

week 42
Tue 2020-10-13
Thur 2020-10-15

In addition, we will have informal discussions for those of you who are interested at a time to be arranged...

The last week (week 43) will be devoted to discussions and summarizing the course.

Contact details

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

Working from home right now but under normal circumstances can be found in Origo room 6111. Tel. 031-772 3157.

Prerequisites (important!)

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

1- you have seen the QED lagrangian

\(-\frac{1}{4} F_{\mu\nu} F^{\mu\nu} + \bar\psi (i \gamma^\mu \partial_\mu - m)\psi\)$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$$-\frac{1}{4}{F}_{\mu \nu }{F}^{\mu \nu }+\overline{\psi }(i{\gamma }^{\mu }{\mathrm{\partial }}_{\mu }-m)\psi$

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}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to e^{-}{e}^{-}$$e^{-}{e}^{-}\to 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

Course literature

To keep us focused I picked these two reviews as the "main texts" for the course:

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

But you will need additional background and explanations. This is where I will try to help with my lectures (see Syllabus below). You can also look at the additional reviews here below where the relevant material is being discussed.

Be careful: It's very easy to get lost browsing the literature on the web! Most of the references contain the same material, but presented from slightly different angles, at different levels of difficulty and always omitting some background material. You need to find what works FOR YOU and stick with it.

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

The Standard Model by H. Osborn.

Introduction to the Standard Model by L. Gibbons.

I am also recording some video lectures now and the links will appear below as they progress.

These combination of regular lectures and prerecorded online videos will help you navigate the material in the two main reviews above (Novaes and Schwartz).

Changes since the last occasion:

The world.

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.  

link to  Studieportalen

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. Here we go:

I) Non abelian gauge invariance and some Lie algebra. (Novaes 1.2)

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. (Novaes 1.3, 1.4.1)

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. (Novaes 2.1.2)

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. 

Examination form