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Fermion Masses. G.G.Ross, Corfu, September 2005. The Standard Model. Masses. 1. GeV. DATA :. ?. Mixing. Masses. 1. GeV. Mixing. 10 -1. 10 -2. 10 -3. 10 -4. eV. DATA :. ?. Bi-Tri Maximal Mixing … Non Abelian Structure?. Perturbative analysis (hierarchical basis).
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Fermion Masses G.G.Ross, Corfu, September 2005 The Standard Model
Masses 1 GeV DATA : ? Mixing
Masses 1 GeV Mixing 10-1 10-2 10-3 10-4 eV DATA : ? Bi-Tri Maximal Mixing … Non Abelian Structure?
Perturbative analysis (hierarchical basis) (small) off diagonal Diagonal Off diagonal
Quark Textures Hierarchical :
Quark Textures Hierarchical :
Symmetric fit Asymmetric fit Roberts Romanino GGR Velasco Sevilla
GATTO, SARTORI, TONIN symmetric / CP SM phase Texture zero Fritzsch, Weinberg Roberts, Romanino, GGR,Velasco
Symmetric fit Asymmetric fit Roberts Romanino GGR Velasco Sevilla
Infra red fixed point Pendleton, Ross Hill Kobayashi, Kubo, Mondragon, Zoupanos
… dimension of operator … order of radiative corrections
Textures and flavour models Symmetries Coherent picture of quark and lepton masses and mixing? Family? Family?
FAMILY SYMMETRY? MESSENGER SECTOR? Symmetries and textures Hierarchical structure strongly suggests a broken symmetry Froggatt, Nielsen
Abelian Family symmetry -3 2 1 -3 2 1 1 -1 Ibanez GGR
Symmetric fit Asymmetric fit Is one favoured?
Probes RH angles Cannot align Yukawa and A terms Vives, GGR Favours near symmetric structure With similar structure for charged leptons Neutrino mixing not related to large RH mixing
Quark masses and mixing angles Lepton masses and mixing angles
Extension to charged leptons – GUT? Georgi Jarlskog
10 100 10-1 10-2 10-3 10-4 eV Extension to neutrinos??? Possible with “see-saw” Dirac Mass Majorana Mass King, GGR
CP violation SUSY CP problem - In string theory CP is a discrete gauge symmetry : Dine, Leigh, MacIntyre Vives, GGR Cannot align Yukawa and A terms OK with suitable family symmetry
Masses 1 GeV Mixing 10-1 10-2 10-3 10-4 eV Fermion Masses II ? Bi-Tri Maximal Mixing … Non Abelian Structure?
Textures and flavour models Symmetries Coherent picture of quark and lepton masses and mixing?
Abelian Family symmetry -3 2 1 -3 2 1 1 -1
Probes RH angles D-term problems for FCNC Family dependent soft mass Murayama Discrete family symmetry Gauge mediated breaking Gravity mediation
Abelian Family symmetry -3 2 1 -3 2 1 1 -1 Ibanez GGR
Abelian Family symmetry -3 2 1 -3 2 1 Need special choice of O(1) coefficients 1 -1 Ibanez GGR
Masses 1 GeV Mixing 10-1 10-2 10-3 10-4 eV DATA : ? Bi-Tri Maximal Mixing … Non Abelian Structure?
Non-Abelian family symmetry Symmetries Coherent picture of quark and lepton masses and mixing? Simple(?) flavour Group restricting Yukawa couplings
I de Medeiros, GGR King, Vives, Velasco Sevilla… Spontaneous symmetry breaking c.f. Georgi-Jarskog only terms allowed by G
Structure determinedfrom symmetries too Neutrino masses Actually cancelled by small off diagonal Majorana terms Bi-Tri Maximal Mixing
Bi-maximal Vacuum alignment Discrete (Non Abelian) family symmetry?
Vacuum alignment Altarelli, Feruglio
Ma; Altarelli, Feruglio Bi-Tri-maximal mixing X Grand Unified King,GGR Allows symmetric invariant - vacuum alignment since only small high dimension corrections Bi-Tri-maximal mixing Grand Unified
Summary Texture and texture zero hints at underlying structure Family symmetry ? GUT symmetry? 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)? Extraction of Yukawa couplings crucial to understanding fermion structure Bounded off diagonal terms (anti)symmetric, hermitian SUSY data
Summary Texture and texture zero hints at underlying structure Family symmetry ? GUT symmetry? 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 and CP problems Extraction of Yukawa couplings crucial to understanding fermion structure Bounded off diagonal terms (anti)symmetric, hermitian SUSY data A discrete non-Abelian subgroup can give vacuum alignment needed For bi-tri-maximal mixing
Ma; Altarelli, Feruglio Neutrinos Charged leptons 3