extension
The standard model overview ii ext
The Standard Model is the current view of the fundamental particles that make up all matter and the forces between them. There are two families of fundamental particles - quarks and leptons. Each particle has an associated anti-particle. The full standard model includes three generations in each family. However, all normal matter is made up of the particles in the first generation. Every particle has a corresponding anti-particle (Table1).
Particles
Forces
Family Gen Particle Antiparticle
lepton 1 electron electron-
neutrino
positron anti-
neutrino
2 muon muon-
neutrino
anti-muon anti-
muon-
neutrino
3 tau tau-
neutrino
anti-
tau
anti-
tau-
neutrino
quark 1 up down anti-
up
anti-
down
2 top bottom anti-
top
anti-
bottom
3 strange charm anti-
strange
anti-
charm
Force Affects Particle
electro-
weak
anything
with charge.
Quarks &
leptons
virtual
photon
W+, W-,
Z0
gravity anything with
mass.

Quarks &
leptons
graviton
strong quarks gluon
Table 1. Table 2
Family Particle Fundamental
lepton electron yes
neutrino yes
hadron proton no (UUD)
neutron no (UDD)
delta - no (DDD)
sigma - no (DDS)
many more
Fundamental or not
The leptons and quarks are all fundamental particles. However, quarks cannot exist on their own. They join up to make a family of particles called the hadrons. These hadrons include protons and neutrons, which are made from the top and bottom quark.
Table 3
The story so far
  • Everything in the Universe is either matter of radiation
  • Scientists are always trying to find simple ways of modelling matter and the way it behaves
  • There are two families of fundamental particle: quarks and leptons