omega meson

The omega meson () 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.

Properties

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

The quark composition of the meson can be thought of as a mix between , and states, but it is very nearly a pure symmetric - state. This can be shown by deconstructing the wave function of the into its component parts. We see that the and 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,
: $\psi_1 = \frac$ and
: $\psi_8 = \frac$.

The mixing angle at which the components decouple completely can be calculated to be $\arctan\frac\approx35.3^\circ$, which almost corresponds to the actual value calculated from the masses of 35°. Therefore, the meson is nearly a pure symmetric - state.

See also

* List of mesons
* Quark model
* Vector meson

References

Mesons
Onia
Subatomic particles with spin 1

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