Textures and flavour models G.G.Ross, Oxford, 21st June 2004 Family? Symmetries Coherent picture of quark and lepton masses and mixing?

DATA : ? 1 GeV Masses Mixing eV Bi-Tri Maximal Mixing … Non Abelian Structure?

DATA : ? 1 GeV Masses Mixing Simple(?) flavour Group restricting Yukawa couplings

Quark Textures Hierarchical :

Quark Textures Hierarchical :

Symmetric fit Asymmetric fit Roberts Romanino GGR Velasco Sevilla Is one favoured?

Vives, GGR Cannot align Yukawa and A terms With similar structure for charged leptons Neutrino mixing not related to large RH mixing Favours near symmetric structure SUSY

Fritzsch, Weinberg Roberts, Romanino, GGR,Velasco CP SM phase / GATTO, SARTORI, TONIN symmetric Texture zero

Georgi Jarlskog Extension to charged leptons – GUT?

Possible with “ see-saw ” Extension to neutrinos??? eV SRHD KingKing,GGR Vives, Velasco-Sevilla, GGR

Neutrino texture zero ? Ibarra, GGR 2β decay, leptogenesis Casas, Ibarra } CHOOZ

2 Texture zeros – 2RHN With charged lepton contribution

King, GGR Vives, Velasco-Sevilla, GGR { Quark lepton symmetry?

Bi- Tri- maximal mixing Barbieri,Hall,Kane, GGR King, GGR de Medeiros Varzielas, GGR

Summary Due to the see-saw mechanism, the quark, charged lepton and neutrino masses and mixing angles can be consistent with a similar structure for their Dirac mass matrices. Hints at an underlying (spontaneously broken) family symmetry? SO(10)XSU(3)? gives a new solution to the SUSY FCNC problem Extraction of Yukawa couplings crucial to understanding fermion structure Bounded off diagonal terms  (anti)symmetric, hermitian   SUSY data  Texture and texture zero hints at underlying structure Family symmetry ? GUT symmetry? A spontaneously broken family symmetry offers a simple solution to the SUSY CP problem