Abstract

These notes are an outgrowth of an advanced undergraduate course taught at the University of Maryland, College Park. They are intended as an introduction to various aspects of particle and nuclear physics with an emphasis on the role of symmetry. The basic philosophy is to introduce many of the fundamental ideas in nuclear and particle physics using relatively sophisticated mathematical tools -- but to do so in as a simplified a context to explain the underlying ideas. Thus, for example, the Higgs mechanism is discussed in terms of an Abelian Higgs model. The emphasis is largely, but not entirely theoretical in orientation. The goal is for readers to develop an understanding of many of the underlying issues in a relatively sophisticated way.

Highlights

  • We have shown that the particles described by this scalar field theory are bosons!! Given this tremendous success, it is time to turn to fermions

  • If we look at the hydrogen atom from far away and forget that it is a composite system made of smaller individual particles, it looks like you have one big particle with an intrinsic negative parity

  • This means that if we have a solution to the Schrödinger equation ψ, we can locally twist its phase to ψ, which is guaranteed to be another solution to the Schrödinger equation with a gauge-transformed version of the potentials

Read more

Summary

Historical Introduction

If one were to ask a contemporary physicist for a simple cartoon overview of our current understanding of fundamental physics they would probably give something like Fig. 1. Rutherford had a brilliant insight: instead of passively studying matter by looking at how some types of matter emit radioactive particles, one could use radioactivity as a probe of matter He designed an experiment carried out at the University of Manchester by a postdoctoral scientist Geiger (of Geiger counter fame) and an undergraduate Marsden, in which α radiation impinged on a thin gold foil, and the angle of their deflection was measured. Prior to this discover it was very difficult to study nuclear dynamics experimentally Charged probes such as α particles from radioactive decays could only penetrate small nuclei due to the strong Coulomb repulsion. While this problem was overcome by cyclotrons, which were able to produce high-energy beams, these were very expensive to build and operate. While this picture is clearly not the entire story, it provides a remarkably simple way to understand some basic features of nuclear physics which apply to a wide-array of nuclei

The Liquid Drop Model
Basic Nuclear Energetics
Measuring Nuclear Density
Modeling the Nucleus
Review of Special Relativity
The Yukawa Potential
The Dirac Equation
All is Not Well with Relativistic Wave Equations
Motivating the Dirac Equation
Solutions to the Dirac Equation
Properties of the Dirac Equation
The Electron Magnetic Moment
Electron Scattering Revisited
Quantum Field Theory for Pedestrians
Review of Classical Mechanics
Classical Field Theory
Quantizing Canonically
Adding Interactions
R is for Renormalization
10 Symmetries in Nuclear and Particle Physics
10.1 Continuous Spacetime Symmetries
10.2 Internal Symmetries and Noether’s Theorem
10.3 Discrete Symmetries
10.4 Discrete Symmetries
10.5 Isospin
10.6 Implications of Isospin
11 Gauge Theories and the Standard Model
11.1 Electromagnetic Gauge Invariance
11.2 Quantum Electrodynamics
11.3 A Quick and Dirty Group Theory Primer
11.4 Quantum Chromodynamics
12 Broken Symmetries
12.1 Symmetry Breaking in Single Particle Physics
12.2 Symmetry Breaking and Phase Transitions
12.3 Symmetry Breaking in Field Theories
13 The Higgs Mechanism
13.2 The Abelian Higgs Model
13.3 Electroweak Symmetry Breaking
15.1 Problems for Sections 2 and 3
Z dgE dq2
15.3 Problems for Section 8
10. We wrote the Hamiltonian density for the free Klein-Gordon theory as
15.4 Problems for Section 9
Findings
15.5 Problems for Section 10
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call