The foregoing quark models completely specify the quantum numbers of π°βmesons. The charge, angular momentum, baryon-number, lepton-number and strangeness are all correct. These models also produce accurate calculated values for the lifetime, width and mass. Results that fall outside of experimental uncertainty are noted with an X in all tables. There are just a handful of these errors from among hundreds of models.

## Particle Cores

Some highly excited states contain so many quarks that may be difficult to see how the models work. So to view the underlying pattern, we remove most of the quark/anti-quark pairs. These pairs are needed for stability. But the field of pairs obscures the minimum number of quarks required to identify a particle and account for its mass. These minima are called *core* coefficients.

The quark coefficients of a particle’s core show more clearly how excited π°βmesons are built-up over blocks of the same baryonic quarks. The mass depends on not . So is unchanged by any variation in the field of pairs. A particle’s rest mass is completely determined by its core quarks.

Experimentally observed values are taken from this reference .

## Sample Calculations for Eta Mesons

Here is a spreadsheet that shows a step-by-step calculation for a specific π°βmeson. For more detail about cell contents and formulae, you can see a read-only, on-line version by clicking on the icon in the black bar at the bottom of the sheet. You can also get a copy of the spreadsheet by clicking on the download link at the bottom of this page. Then you may enter other quark-coefficients in the yellow field to assess other particles.