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

2. DATA : ? 1 GeV Masses Mixing 10 -1 10 -2 10 -3 10 -4 eV Bi-Tri Maximal Mixing … Non Abelian Structure?

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

4. Quark Textures Hierarchical :

5. Quark Textures Hierarchical :

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

7. 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

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

9. Georgi Jarlskog Extension to charged leptons – GUT?

10. Possible with “ see-saw ” Extension to neutrinos??? 10 0 10 -1 10 10 -2 10 -3 10 -4 eV SRHD KingKing,GGR Vives, Velasco-Sevilla, GGR

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

13. 2 Texture zeros – 2RHN 0.22 0.08 With charged lepton contribution

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

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

16. 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