Challenge to the Mystery of the Charged Lepton Mass Formula
Yoshio Koide · arXiv (Cornell University) · 2005
Why the charged lepton mass formula m_e +m_μ+m_τ= {2/3} (\sqrt{m_e}+\sqrt{m_μ} +\sqrt{m_τ})^2 is mysterious is reviewed, and guiding principles to solve the mystery are presented. According to the principles, an example of such a mass generation mechanism is proposed, where the origin of the mass spectrum is attributed not to the structure of the Yukawa coupling constants, but to a structure of vacuum expectation values of flavor-triplet scalars under Z_4 \times S_3 symmetries.