The bridge between the electron and the other elementary particles is provided by the fine structure constant, a ~ 1/137, as manifested in the factor-of-137 spacings between the classical electron radius, electron Compton radius, and Bohr orbit radius. ... An a-quantized mass-generation grid extends accurately from the electron all the way to the top quark t, and leads to a corresponding a-quantized particle lifetime grid.
Malcolm H. Mac Gregor, The Enigmatic Electron: A Doorway to Particle Masses
electrons, fine-structure-constant, physics