CHARGED LEPTON MASS FORMULA — DEVELOPMENT AND PROSPECT

摘要

The recent devolopment on the charged lepton mass forumula m_e + m_u + m_r = 2/3((m_e)~2(1/2) + (m_u)~2(1/2) + (m_r)~2(1/2))~ 2 is reviewed. An S3 or A4 model will be promising for the mass relation.