Fermions

Introduction

• Fermions are a fundamental category of subatomic particles that make up matter in the universe.
• They are distinct from bosons, which are particles associated with fundamental forces.

Classification of Matter Particles

• While we commonly think of matter as composed of protons, neutrons, and electrons, the full set of matter particles is the fermions, which include a more diverse range of subatomic particles.

Fermion Family Tree

• Fermions can be organised into two main branches:
  • Leptons: These are particles that can exist independently and are not subject to strong nuclear forces.
  • Hadrons: These are heavier particles, which include protons and neutrons, and are subject to strong nuclear forces.

Leptons

• Electrons are one of the six types of leptons.
• Leptons are elementary particles that do not consist of smaller constituents and can exist on their own.

Hadrons

• Protons and neutrons are part of the hadron family.
• All hadrons are composed of quarks, which are fundamental particles that can only exist in bound states with other quarks.
• Hadrons are divided into two types:
  • Baryons: Made up of three quarks. Both protons and neutrons are examples of baryons.
  • Mesons: Made up of a quark and an antiquark pair.

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Fermions

Types of Quarks

• There are six types of quarks, each with its unique properties.
• Quarks are responsible for the electrical charge and other characteristics of hadrons.

Fermions as Matter Particles

• Fermions, including quarks and leptons, are the building blocks of matter in the universe.
• Their properties, including mass, charge, and spin, play crucial roles in the structure of atoms and the behaviour of matter.

Explaining Particle Properties

• The properties of subatomic particles, such as their electrical charge and mass, can be understood by examining their composition and the interactions between their constituent particles.

Summary

• Fermions are a diverse group of subatomic particles that make up matter.
• They include leptons, such as electrons, and hadrons, which consist of quarks.
• Quarks are responsible for the charge and characteristics of hadrons.
• Understanding the composition and properties of fermions is essential for understanding the nature of matter in the universe.