Introduction - Elementary Particles

What is the world made from? What are the building blocks of the universe? Answer: There are 2 types of elementary particle - Fundamental Bosons (responsible for force and mass) & Fundamental Fermions (Quarks & Leptons).

Any other particles are composed of multiple elementary particles - and such composite particles are called Hadrons. Again, there are 2 types of Hadron - Composite Bosons (Mesons) and Composite Fermions (Baryons).

The over-arching principle is that particles (elementary and composite) are divided into 2 categories - Bosons and Fermions. Bosons are somewhat ethereal concepts - they aren't actually matter itself but responsible for the interactions between matter particles. So the real building blocks of the universe are Fermions - Quarks and Leptons which when combined create protons, neutrons and thus atoms, molecules and everything that makes up real stuff - animals, vegetables and minerals.


Formal definition of a boson = particles conforming to Bose-Einstein Statistics

Fundamental Bosons (elementary particles)

Composite Bosons - Mesons

Mesons are composed of 1 Quarks and 1 anti-Quark. There are literally dozens of them; too many to list here but well known ones include:


Formal definition of a fermion = particles conforming to Fermi-Dirac Statistics

Fundamental Fermions - Quarks & Leptons

Composite Fermions - Baryons

Baryons are made from 3 Quarks e.g.