Standard Model of Particles

The Standard Model of physics explains the relationships between three of the four fundamental forces, and the particles which carry them. It is not a complete description since it does not include the force of gravity.

The models says that particles occur in two basic types called quarks and leptons.

Each type consists of six particles, which are related in pairs, or ‘generations'. The lightest and most stable particles make up the first generation, whereas the heavier and less stable particles belong to the second and third generations. All stable matter in the Universe is made from particles that belong to the first generation; any heavier particles quickly decay to the next most stable level.

This diagram shows the general arrangement of the 6 particles.

 

 

We show this diagram for each of the two types of particle in the standard model.

Force-carrier particles

The Standard Model tells us that three of the fundamental forces result from the exchange of force-carrier particles, which belong to a broader group called ‘bosons'. So far the fourth force (gravity) does not fit into this model.

Matter particles transfer discrete amounts of energy by exchanging bosons with each other. Each fundamental force has its own corresponding boson particle.

 

 

Limitations on Standard Model

The Standard Model has led to some spectacularly accurate predictions, and its general principles have been well established. But some people think that the model is less credible because it requires about 20 constants to be established by experiment. They think that a good theory ought to be able to predict what these constants are.

The fact that the Higgs boson has not yet been fully describes shows that the Standard Model does not explain everything. Nor does it tell what Dark Energy or Dark Matter are made of.

Another outstanding failure of the Standard Model is that it cannot explain the force of gravity. As explained elsewhere, our basic laws of science are incomplete, and so is the Standard Model.