Family Gauge Symmetry and Koide's Mass Formula
  Koide's mass formula is an empirical relation among the charged lepton masses which holds with a striking precision. We propose a mechanism for cancelling the QED correction to Koide's formula. This is discussed in an effective theory with U(3) family gauge symmetry and a scenario in which this symmetry is unified with SU(2)_L symmetry at 10^2-10^3 TeV scale. 
Y. Sumino