370 likes | 465 Views
KITPC Program on Neutrino Physics 2008.9.1-9.21. Nearly Tri-bimaximal Mixing & Small Masses of Neutrinos. Yue-Liang Wu Kavli Institute for Theoretical Physics China (KITPC) Institute of Theoretical Physics Chinese Academy of Sciences. 78 Years Old Neutrino.
E N D
KITPC Program on Neutrino Physics 2008.9.1-9.21 Nearly Tri-bimaximal Mixing & Small Masses of Neutrinos Yue-Liang Wu Kavli Institute for Theoretical Physics China (KITPC) Institute of Theoretical Physics Chinese Academy of Sciences
78 Years Old Neutrino 1930 Pauli (30 years old): Neutrino withs=1/2、NWIP、m < m_e To solve energy conservation problem and spin- statistical probleminvolved in decay 1933 Fermi: H_3 He_3 + e + anti- 1957 T.D.Lee & C.N.Yang: Parity Non-conservation(NP) C.S. Wu: Experimental Test 1957 Landau, Lee & Yang, Salam Two Component Theory of Massless Neutrino m_ =0, Maximal Parity Violation 1958 Feynman-Gell-Mann, Marshak-Sudarshan V-A Theory 1967 GWS Standard Model: SU(2)_L x U(1) (NP) Based on Massless Neutrinos
1957 Pontecorvo Massive neutrinos、Neutrino Mixing & Oscillations _e anti-_e 1957 R.Davis: Reactor Experiment anti- + Cl_37 e + Ar_37 1962 Lederman, Schwartz & Steinberge Observed _ at Brookhaven (NP) 1962 MNS – Maki-Nakagawa-Sakata Lepton Mixing Angle: 1967 Pontecorvo _e _ Solar Neutrino Puzzle: ½
1967 R. Davis Solar Neutrino Experiment (NP) • 1969 Gribov & Pontecorvo Majorana-type Neutrino Mixing • 1976 Bilenky & Pontecorvo • Dirac-type Neutrino Mixing • 1978 L. Wolfenstein; 1986 S.P. Mikheyev and A. Yu. Smirnov Matter Effects of Neutrino Oscillations (MSW) • 1979 See-Saw Mechanism & GUTs • 1994: ‘1,3,5 ’ - Massive, ‘ 2,4,6 ’ -Massless, 7 - No think 1998.6Super-Kamiokande Experiment Evidence of Massive Neutrinos & Neutrino Oscillations Answer Question: Massive or Massless?
Unknown Questions: Neutrinos are Dirac or Majorana? Absolute Values of Neutrino Masses? Hierarchy or Degeneracy? CP Violation in Lepton-Neutrino Sector? How Many Neutrinos,Sterile Neutrinos? Leptogenesis and Matter-Antimatter Asymmetry? Rules of Neutrino in Astrophysics and Cosmology ?
Theoretical Questions Why neutrino masses are so small Why neutrino mixings are so large in comparison with quark mixings 23is exactly maximal? 13?,Ue3 0? Mass hierarchy m312 > 0 ?m312 < 0?
Flavor changing at 5.3s Solar Neutrino: SNO Electron neutrino generated from Sun arXiv:nucl-ex/0610020
Reactor neutrino: KamLAND arXiv:0801.4589 A scaled reactor spectrum without distortions from neutrino oscillation is excluded at more than 5σ! Oscillation parameters:
Atmosphere Neutrino: Super-K Oscillation parameters:
Neutrino Oscillation General Formalism: J. Valle et al. hep-ph/0405172, updated at Sep 2007 Solar: Super-K, SNO Atmosphere: Super-K Reactor:KamLAND, CHOOZ Accelerator:K2K,MINOS
Issues in Neutrino Physics 1. Dirac / Majorana Neutrinoless Double Beta Decay 2. Mass scale: m1 Neutrinoless Double Beta Decay, Single Beta Decay, Cosmology 3. Sterile neutrinos, LSND? MiniBooNE Excludes at 98% CL two-neutrino appearance oscillations as an explanation of the LSND anomaly. arXiv:0704.1500 (3+1): inconsistency at the level of 4σ. (3+2) ,(3+3): severe tension at the level of more than 3σ. arXiv:0705.0107
Neutrino Masses 1. Cosmology (CMB+LSS): Planck: 0.025-0.1 eV 2. Single Beta Decay KATRIN: 0.2 eV 3. Neutrinoless Double Beta Decay CUORE: 0.02-0.1 eV Strumia-Vissani arXiv:hep-ph/0503246
Global fits: 3σ Kam-Biu Luk, Jan 8 2007 Int'l Symp on Neutrino Physics and Neutrino Cosmology arXiv:hep-ex/0509019
N Seesaw Mechanism Type II? Type III? Leptogenesis Mechanism Fukugita & Yanagida (1986):
Other Mechanism for Neutrino Masses E. Ma, PRD 73, 077301, 2006 Two Higgs doublets Model: S or A may be Dark Matter! R. Barbieri, L. Hall and V.S. Rychkov, PRD 74, 015007, 2007 3 loop generation of neutrino masses: L.M. Krauss, S. Nasri and M. Trodden, PRD 67, 085002, 2003 Right-handed neutrino as Dark Matter!
Family Symmetry Tri-Bimaximal Mixing: (Harrison,Perkins and Scott) Friedberg-Lee Symmetry: Some papers: Xing, Zhang, Zhou, PLB641 Luo, Xing, PLB 646 C.S. Huang, T.J. Li, W. Liao and S.H. Zhu, arXiv:0803.4124 hep-ph/0606071 Invariant under Friedberg-Lee symmetry: z a space-time independent constant element of the Grassmann algebra
F. Harrison, D. H. Perkins and W. G. Scott, Phys. Lett. {\bf B 530}, 167 (2002) • Z.-Z. Xing, Phys. Lett. {\bf B533}, 85(2002). • P. F. Harrison and W.G. Scott, Phys. Lett. {\bf B535},163(2002). • P.F. Harrison and W. G. Scott, Phys. Lett. {\bf B557},76(2003). • X. G. He and A. Zee, Phys. Lett. {\bf B560}, 87(2003). • C.I. Low and R. R. Volkas, Phys. Rev. {\bf D68}, 033007 (2003). • E. Ma, Phys. Rev. {\bf D70}, 031901R(2004); E.Ma, hep-ph/0701016 • G. Altarelli and F. Feruglio, Nucl. Phys. {\bf B720}, 64(2005); • E. Ma, Phys. Rev. D72, 037301 (2005).; • E. Ma, Mod.\ Phys.\ Lett.\ A 20, 2601 (2005) • A. Zee, Phys. Lett. {\bf B630}, 58 (2005). • E. Ma, Phys.\ Rev.\ D {\bf 73}, 057304 (2006). • G. Altarelli and F. Feruglio, Nucl. Phys. {\bf B741}, 215(2006). • W. Grimus and L. Lavoura, {\bf JHEP}, 0601:018(2006). • J.E. Kim and J.-C. Park, {\bf JHEP} 0605:017(2006). • N. Singh, M. Rajkhowa and A. Borach, hep-ph/0603189. • R. Mohapatra, S. Naris and Y.-H. Yu, Phys.Lett. {\bf B639} 318 (2006). • P. Kovtun and A. Zee, Phys.Lett. {\bf B640} (2006) 37. • N. Haba, A. Watanabe and K. Yoshioka, Phys.Rev.Lett. 97 (2006) 041601. • X.G. He, Y.Y. Keum and R. Volkas, {\bf JHEP}, 0604:039(2006). • Varizelas, S.-F. King and G.G. Ross, Phys.Lett. B644 (2007) 153. • R. Friedberg and T. D. Lee, arXiv:hep-ph/0606071; arXiv:hep-ph/0705.4156 • B.Hu, F. Wu and Y.L. Wu, Phys.Rev. {\bf D75} 113003 (2007).
SO(3) Gauge Model Exact Discrete symmetry Tri-bimaximal with 13= 0 Experimental Data (99%) Gauge Symmetry has been well tested
Why SO(3) Gauge Model?YLWarXiv:0708.0867, PRD 2008 • Why lepton sector is so different from quark sector ? Neutrinos are neutral fermions and can be Majorana! Majorana fermions only have real representations They possess orthogonal symmetry • Invariant Lagrangian for Yukawa Interactions
Uniqueness of Lagrangian & New Particles • Symmetry
SO(3) Expression of Tri-triplet Higgs Bosons In terms of SO(3) representation:
Symmetry as Subgroup of SO(3) • Discrete symmetric group: • Cyclic permutation group: • Coset space : • Cyclic permuted form: with i+j-1 mod. 3
Why Local SO(3) Symmetry • Fixing Gauge: • invariant Lagrangian • In terms of SO(3) Representation
Vacuum Structure With the given fixing gauge:
Type-II like (generalized) see-saw mechanism For neutrinos: For charged leptons:
Global U(1) Family Symmetries • For Infinite Large Majorana neutrino masses • Majorana neutrinos decouple • Generating global U(1) family symmetries U(1)_1 x U(1)_2 x U(1)_3 • Large but Finite Majorana Neutrino Masses • ???
Small Mass and Large Mixing of Neutrinos Approximate global U(1) family symmetries Smallness of neutrino masses and charged lepton mixing Neutrino mixings could be large !!!
Nearly Tri-bimaximal neutrino mixings Neutrino and charged lepton mixings: ≈
Lepton Mixing Matrix and Neutrino Masses CKM-like Lepton mixing: Neutrino Masses Heavy Majorana Masses
Numerical Results 4 Parameters: / / Two inputs: Neutrino masses with given parameter
Considering the hierarchy: One parameter in Vacuum: Interesting case: Two cases for charged lepton mixing:
Taking Optimistic Predictions Which can be detected by the future neutrino Experiments, like Daya Bay
Vector-Like Heavy Neutrino and Charged Lepton Masses Taking and It leads to and Taking The lightest vector-like charged lepton mass Which may be detected at LHC/ILC
Summary • Smallness of neutrino masses and charged lepton mixing could be understood from approximate global U(1) family symmetries • Tri-bimaxiaml neutrino mixing is obtainable from the vacuum structure of SO(3) gauge symmetry • 13 is in general non-zero and testable at the experimental sensitivity • Some of the vector-like fermions could have masses at electroweak scale and be probed at LHC • The mechanism can simply be extended to quark sector for smallness of quark mixing