Force Carrier - Particle and Field Viewpoints

Particle and Field Viewpoints

In particle physics, quantum field theories such as the Standard Model describe nature in terms of fields. Each field has a complementary description as the set of particles of a particular type. A force between two particles can be described either as the action of a force field generated by one particle on the other, or in terms of the exchange of virtual force carrier particles between them.

The energy of a wave in a field (for example, electromagnetic waves in the electromagnetic field) is quantized, and the quantum excitations of the field can be interpreted as particles. The Standard Model contains the following particles, each of which is an excitation of a particular field:

• Gluons, excitations of the strong gauge field.
• Photons, W bosons, and Z bosons, excitations of the electroweak gauge fields.
• Higgs bosons, excitations of one component of the Higgs field, which gives mass to fundamental particles.
• Several types of fermions, described as excitations of fermionic fields.

In addition, composite particles such as mesons can be described as excitations of an effective field.

Gravity is not a part of the Standard Model, but it is thought that there may be particles called gravitons which are the excitations of gravitational waves. The status of this particle is still tentative, because the theory is incomplete and because the interactions of single gravitons may be too weak to be detected.