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Omega meson

Subatomic particle

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Source updated April 3, 2026

The omega meson (ω) is a flavourless meson formed from a superposition of an up quark, antiquark and a down quark, antiquark pair. It is part of the vector meson nonet and mediates the nuclear force along with pions and rho mesons.

01Properties

The most common decay mode for the ω meson is π⁺
π⁰
π⁻
at 89.2%±0.7%, followed by π⁰
γ at 8.34%±0.26%.

Particle name	Particle symbol	Antiparticle symbol	Quark content	Rest mass (MeV/c²)	I^G	J^{P C}	S	C	B'	Mean lifetime (s)	Commonly decays to (>5% of decays)
Omega meson	ω(782)	Self	${\textstyle {\frac {u{\bar {u}}+d{\bar {d}}}{\sqrt {2}}}$	782.66 ± 0.13	0⁻	1⁻⁻	0	0	0	(7.58±0.11)×10⁻²³ s	π⁺ +π⁰ +π⁻ or π⁰ +γ

The quark composition of the ω meson can be thought of as a mix between uu, dd and ss states, but it is very nearly a pure symmetric uu, dd state. This can be shown by deconstructing the wave function of the ω into its component parts. We see that the ω and ϕ mesons are mixtures of the SU(3) wave functions as follows.

$\omega =\psi _{8}\sin \theta +\psi _{1}\cos \theta$ ,

$\phi =\psi _{8}\cos \theta -\psi _{1}\sin \theta$ ,

where

$\theta$ is the nonet mixing angle,

$\psi _{1}={\frac {u{\overline {u}}+d{\overline {d}}+s{\overline {s}}}{\sqrt {3}}}$ and

$\psi _{8}={\frac {u{\overline {u}}+d{\overline {d}}-2s{\overline {s}}}{\sqrt {6}}}$ .

The mixing angle at which the components decouple completely can be calculated to be ${\textstyle \arctan {\frac {1}{\sqrt {2}}}\approx 35.3^{\circ }$ , which almost corresponds to the actual value calculated from the masses of 35°. Therefore, the ω meson is nearly a pure symmetric uu, dd state.

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Sources and credits

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Omega meson

01Properties

Sources and credits

Related topics

List of mesons

Quark model

Vector meson