International standards and resources
Rules for particle symbols are complex. They are published in Review of particle physics(Opens in a new tab/window), which is published biennially by the Particle Data Group, CERN.
Australian conventions and resources
Australia follows the international conventions.
The term particle in particle physics refers to the smallest subatomic particles. The smallest particles are the elementary particles (gauge bosons, leptons, quarks and hadrons). Elementary particles combine to form composite particles (protons and neutrons).
Use lower case for particle names unless they include a proper noun:
quark neutrino muon gauge boson Higgs boson
Symbols for elementary and composite particles are often given as italic Greek or roman letters:
γ Z
However, there is no accepted standard, and some journals do not use italics for these symbols.
Sometimes the symbols are accompanied by superscript or subscript modifiers (e.g. subscript s and c for strange and charmed quarks):
Bc Bs
Charge is added as a superscript (0, +, –):
K0 B–
The symbols p and e refer to a positive proton and negative electron, respectively, without the need for a further charge superscript; however, it is common to see the symbol e– for an electron.
Antimatter particles are indicated by a bar above the symbol:
\(\overline{p}\) \(\overline{e}\)
Electron orbitals are designated with arabic numbers, and italic letters and subscripts:
1s 2s 2px 2py 2pz
Use initial capitals for Standard Model, which is the complete theory of interactions between particles.
Do not capitalise terms such as cold dark matter (abbreviated to CDM).
Reminder. Just because the abbreviation of a term is made up of capitals, it does not mean that the term has initial capitals when it is spelt out.