Charged Lepton Mass Formula -- Development and Prospect --

Abstract

The recent devolopment on the charged lepton mass forumula m_e+m_{\mu}+m_{\tau}={2/3}(\sqrt{m_e}+\sqrt{m_\mu}+\sqrt{m_{\tau}})^2 is reviewed. An S_3 or A_4 model will be promising for the mass relation.

Comments: Latex, 11 pages, no figure, Talk at Internationa Workshop on Neutrino Masses and Mixing, at Shizuoka, Japan, December, 17-19, 2006