# Electron-to-proton mass ratio

⏎## fully understood?

⏎
⏎
⏎
## https://en.wikipedia.org/wiki/Proton-to-electron_mass_ratio

- https://en.wikipedia.org/wiki/Coupling_constant

> The proton-to-electron mass ratio is primarily determined by the QCD scale.

- https://en.wikipedia.org/wiki/Hierarchy_problem

# Parents

* Fundamental Dimensionless numbers in Physics- P
* Quantum Chromodynamics (QCD)