Standard Model of Particle Physics

Quarks

Up

2.2 GeV/c²

0.666e

0.5ħ

Down

4.7 GeV/c²

-0.333e

0.5ħ

Charm

1.28 GeV/c²

0.666e

0.5ħ

Strange

96 GeV/c²

-0.333e

0.5ħ

Top

173.1 GeV/c²

0.666e

0.5ħ

Bottom

4.18 GeV/c²

-0.333e

0.5ħ

Leptons

Electron

0.511 GeV/c²

-1e

0.5ħ

Muon

105.66 GeV/c²

-1e

0.5ħ

Tau

1.7768 GeV/c²

-1e

0.5ħ

Electron Neutrino

1 GeV/c²

0.5ħ

Muon Neutrino

0.17 GeV/c²

0.5ħ

Tau Neutrino

18.2 GeV/c²

0.5ħ

Gauge Bosons

Gluon

0 GeV/c²

1ħ

Photon

0 GeV/c²

1ħ

Z Boson

91.19 GeV/c²

1ħ

W Boson

80.36 GeV/c²

1ħ

Scalar Bosons

Higgs Boson

124.97 GeV/c²

0ħ

Classes

Quarks

Quarks are fundamental particles that make up hadrons like protons and neutrons. There are six flavors of quarks: up, down, charm, strange, top, and bottom. Quarks have fractional electric charges, carry color charge, and are subject to all four fundamental forces.

Leptons

Leptons are fundamental particles that are not composed of quarks. There are six types of leptons: electron, muon, tau, and their corresponding neutrinos (electron neutrino, muon neutrino, tau neutrino). Charged leptons (electron, muon, tau) interact through electromagnetic and weak forces, while neutrinos only interact through the weak force.

Gauge bosons

Gauge bosons are force-carrying particles that mediate the fundamental interactions. The photon mediates the electromagnetic force, gluons mediate the strong force, and W and Z bosons mediate the weak force. These particles have integer spin and are responsible for the exchange of forces between particles.

Scalar bosons

The Higgs boson is a fundamental particle associated with the Higgs field. It plays a crucial role in the Standard Model by giving mass to other fundamental particles. The Higgs boson was the last particle of the Standard Model to be experimentally observed, confirming its existence in 2012.

Properties

Mass

Mass is measured in GeV/c². Larger particles represent heavier masses.

Charge

Electric charge is measured in units of e. Red indicates positive charge, blue indicates negative charge.

Spin

Spin is measured in units of ħ. Clockwise rotation indicates positive spin, counter-clockwise indicates negative spin.

Fundamental interactions

Strong

The strong interaction is responsible for binding quarks together to form hadrons (like protons and neutrons) and holding atomic nuclei together. It is mediated by gluons and only affects particles with color charge.

Weak

The weak interaction is responsible for radioactive decay and plays a crucial role in nuclear fission. It is mediated by W and Z bosons and affects all fermions (quarks and leptons).

Electromagnetic

The electromagnetic interaction occurs between electrically charged particles, governing phenomena like attraction and repulsion between charged particles, as well as the behavior of light. It is mediated by photons.

Gravitational

The gravitational interaction affects all particles with mass or energy and is believed to be mediated by hypothetical particles called gravitons.

Feynman diagrams

Electron-electron scattering

Electron-positron annihilation

Neutron beta decay