Lesson 16, Topic 4
In Progress

Force Carrier Particles

Lesson Progress
0% Complete

All interactions between particles may be explained in terms of four fundamental forces:

  1. Electromagnetic force (photon)
  2. Strong nuclear force (gluon)
  3. Weak nuclear force (W and Z bosons)
  4. Gravitational force (not explained by the standard model)

These forces can cause particles to attract, repel or transform into different types of particles. Forces in the standard model are mediated by force carrier particles, known as force carrier bosons.

Photon – Electromagnetism

  • Range of effect is infinite, as photons have no mass
  • Force experienced by everything with charge
  • Holds atoms and molecules together through attraction between nucleus and electrons, and attraction between atoms in a molecule
  • Also repels like charges, for example, two electrons

Gluon – Strong Force

  • Short range (~10-15 m)
  • Experienced only by quarks
  • Holds hadrons together, and holds the nucleus together

W and Z Boson – Weak Force

  • The only force that can change the flavour (type) of a quark or lepton
  • Allows quarks and leptons to interact
  • The only force that can change the charge of a particle, as W+ and W are the only charged force carriers

Example: Beta-minus decay. The weak force turns a down quark into an up quark, hence turning a neutron into a proton.