1. Neutrinos and Flavour G.G.Ross, Coseners House, May 03 What is the origin of the Quark and lepton masses, mixing angles and CP violating phases? Family?

2. DATA : Mixing ? 1 GeV Masses THEORY :

3. DataTheory ? Underconstrained – need mixing angles but only V CKM measured. HierarchyDemocracy

4. Hierarchy

5. Symmetric fit Asymmetric fit Roberts Romanino GGR Velasco Sevilla DataTheory

6. Georgi Jarlskog Extension to charged leptons – GUT?

7. Family symmetries Hierarchical structure strongly suggests a broken symmetry MESSENGER SECTOR? FAMILY SYMMETRY? Froggatt, Nielsen

8. Abelian Family symmetry -3 2 1 -3 2 1    1 Ibanez GGR 

9. Asymmetric charge assignment : } Large mixing… maximal? Ramond et al, Jack, Jones, …..

10. Non-Abelian family symmetry Near Bi (-Tri) maximal mixing suggests Non-Abelian symmetry capable of relating Candidate group ? Numerous suggestions for the symmetries of C3, S3, A4… Harrison, Scott, Perkins Babu, Ma, Valle Wetterich… But can such structures be consistent with all quark and lepton masses? U(2), U(3)Various attempts : Barbieri et al, Chkareuli, Froggattt, Nielsen King, GGR….

11. King, GGR  Coefficients equal due to SU(2) family symmetry   ? ? 3

12. Possible with “ see-saw ” Extension to neutrinos??? Majorana Mass Dirac Mass 10 0 10 -1 10 10 -2 10 -3 10 -4 eV King, GGR

13. SUMMARY The measurement of neutrino properties is testing our ideas about the origin of flavour and raises interesting questions : Is there a connection between quarks and leptons? GUT? Tests? Is there a family symmetry? Abelian? Non-Abelian? Origin of the hierarchy? Froggatt Nielsen? Radiative corrections? New spatial dimensions? Origin of CP violation? Spontaneous?

14. Probes RH angles TESTS? Vives, GGR, Velasco Sevilla

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

17. (SUSY) Textures : FCNC, CP constraints Vives, GGR