Course-PM

Standard model of particle physics

TIF355 / FYM355   (Chalmers U./Gothenburg U.)  lp1 HT22 (7.5 hp) 

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Welcome to the course! This is a preliminary homepage reproducing last year's content. There might be last minute changes. Let's all hope the pandemic is behind us...

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

Muon_pion_decay.pdf 

DY PDF DIS

W Z and top

Higgs

Contact details

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

Can be found in Origo room 6111. Tel. 031-772 3157. Mobile: 0721582259

Student representatives: (will be added here)

Prerequisites (important!)

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

1- you have seen the QED lagrangian

\(-\frac{1}{4} F_{\mu\nu} F^{\mu\nu} + \bar\psi (i \gamma^\mu D_\mu - m)\psi\)$-\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

The course content consist of the material in the videos below, as well as the first three papers below and my lecture notes. 

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

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

Additional material can be found below, for those who want to delve deeper into some of the issues. I will add/remove material as we go along, depending on your interests/questions.

Introduction to the Standard Model by L. Gibbons.

Collider Physics within the Standard Model by G. Altarelli.

Changes since the last occasion:

(Hopefully no restrictions!)

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. 

Examination form