Elementary particle
An elementary particle is one of the basic building blocks of matter. All the matter around us is made of elementary particles.[1] Scientists describe them using a theory called the Standard Model, which includes the particles of matter (quarks and leptons), the particles that carry forces (bosons) and the Higgs boson.[2]
Particles of matter
The particles that make up matter come in two basic types, called quarks and leptons. Each type has six particles, which are related in pairs called "generations".[3] The lightest and most stable particles form the first generation, while heavier and less stable ones belong to the second and third generations. All stable matter in the universe is made of first-generation particles, because heavier particles quickly decay into more stable ones.[4] The electron is an example of a lepton.[5]
Particles that carry forces
Three of the four fundamental forces work through the exchange of force-carrying particles, which belong to a wider group called bosons. The strong force is carried by the gluon, the electromagnetic force by the photon, and the weak force by the W and Z bosons.[6][7] A particle called the graviton is expected to carry gravity, but it has not been found.[8]
The Higgs boson gives mass to quarks, charged leptons and the W and Z bosons. Scientists do not yet know whether it also gives mass to neutrinos, particles that very rarely interact with other matter.[9]
Limits of the Standard Model
The Standard Model explains three of the four fundamental forces: electromagnetism, the strong force and the weak force. The fourth, gravity, is not properly explained by it.[10][11] Physicists also think that about 95 per cent of the universe is not made of ordinary matter, but of dark matter and dark energy, which do not fit into the Standard Model.[12]
References
- ↑ "The Standard Model". CERN. Retrieved 20 October 2026.
All matter around us is made of elementary particles, the building blocks of matter.
- ↑ "DOE Explains...the Standard Model of Particle Physics". US Department of Energy, Office of Science. Retrieved 20 October 2026.
The Standard Model includes the matter particles (quarks and leptons), the force carrying particles (bosons), and the Higgs boson.
- ↑ "The Standard Model". CERN. Retrieved 20 October 2026.
These particles occur in two basic types called quarks and leptons. Each group consists of six particles, which are related in pairs, or "generations".
- ↑ "The Standard Model". CERN. Retrieved 20 October 2026.
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.
- ↑ "DOE Explains...the Standard Model of Particle Physics". US Department of Energy, Office of Science. Retrieved 20 October 2026.
charged leptons (like electrons )
- ↑ "The Standard Model". CERN. Retrieved 20 October 2026.
Three of the fundamental forces result from the exchange of force-carrier particles, which belong to a broader group called "bosons".
- ↑ "The Standard Model". CERN. Retrieved 20 October 2026.
the strong force is carried by the "gluon", the electromagnetic force is carried by the "photon", and the "W and Z bosons" are responsible for the weak force.
- ↑ "The Standard Model". CERN. Retrieved 20 October 2026.
Although not yet found, the "graviton" should be the corresponding force-carrying particle of gravity.
- ↑ "DOE Explains...the Standard Model of Particle Physics". US Department of Energy, Office of Science. Retrieved 20 October 2026.
the Higgs boson gives mass to quarks, charged leptons (like electrons ), and the W and Z bosons. However, we do not yet know whether the Higgs boson also gives mass to neutrinos – ghostly particles that interact very rarely with other matter in the universe.
- ↑ "DOE Explains...the Standard Model of Particle Physics". US Department of Energy, Office of Science. Retrieved 20 October 2026.
The Standard Model explains three of the four fundamental forces that govern the universe: electromagnetism , the strong force , and the weak force .
- ↑ "DOE Explains...the Standard Model of Particle Physics". US Department of Energy, Office of Science. Retrieved 20 October 2026.
The fourth fundamental force is gravity, which is not adequately explained by the Standard Model.
- ↑ "DOE Explains...the Standard Model of Particle Physics". US Department of Energy, Office of Science. Retrieved 20 October 2026.
physicists understand that about 95 percent of the universe is not made of ordinary matter as we know it. Instead, much of the universe consists of dark matter and dark energy that do not fit into the Standard Model.