CP iolation and Flavor Mixing Makoto Kobayashi KEK and JSPS
Plan 1. Introduction to the Standard Model 2. Sakata and His Group 3. The CP Paper with Maskawa 4. Experimental erification at B-factories 5. Lepton Flavor Mixing
Introduction to the Standard Model Electron p u d u Proton(p) n Nucleus d d u Atom Neutron(n)
Introduction to the Standard Model Fundamental Particles Quark u d c s t b Lepton e μ τ Fundamental Interactions ν e ν μ ν τ Strong Interaction Electro Magnetic Interaction Weak Interaction QCD Weinberg Salam Glashow Theory
Introduction to the Standard Model Established in 1970 s Development of gauge theory 1971 t Hooft Electro Magnetic Interaction Strong Interaction Weak Interaction Discoveries of new flavors 1964 Gell Mann quark model u, d, s u d c s t b e μ τ ν e ν μ ν τ 1973 Kobayashi Maskawa Six Quark Model After 1970
Sakata and His Group 1947 Discovery of Strange Particles Hadron : strongly interacting particle p n ±0 π Λ Λ 0 Σ ± Ξ K ± 1956 Sakata Sakata Model K Strange Particles 0 Λ Courtesy of Sakata Memorial Archival Library Shoichi Sakata 1911-1970 All the hadrons are composite states of p, n, Λ : Fundamental Triplet
Sakata and His Group Weak Interaction in the Sakata Model β - decay strange paticle p n p + e Λ p + e ν + ν + ν n Λ e μ 1959 Gamba, Marshak, Okubo B L Symmetry 1960 Maki, Nakagawa, Ohnuki, Sakata Nagoya Model : + + p = B ν, n = B e, Λ = B + μ
Sakata and His Group 1962 Discovery of Two Neutrinos ν e ν μ e μ 1962 Maki, Nakagawa, Sakata + p = B ν, n = B e, Λ = B μ, p' = B ν ν 1 2 = + + + 1 ν 2 cosθ ν + sinθ ν = sinθ ν + cosθ ν e e Neutrino Oscillation μ μ 4 th Fundametal Particle (GIM scheme) 1962 Katayama, Matumoto, Tanaka, Yamada Lepton Flavor Mixing MNS Matrix
Sakata and His Group Cosmic Ray Events 1971 Niu et al. Evidence for the 4 th element? Some Japanese groups began to investigate the four-quark model Emulsion Technique Applied to accelerator exp. Life time measurement of the new flavors
CP Paper with Maskawa 1971 t Hooft : Renormalization of Non-Abelian gauge theory Renormalizable Electro-Weak Theory (Weinberg-Salam-Glashow ) 1973 Kobayashi, Maskawa How to accommodate CP violation What we found Not possible in four-quark models Existence of unknown particles A possible candidate is six-quark model CP iolation 1964 Cronin et al. K L ππ Essential difference between particles and anti-particles
CP Paper with Maskawa s c d u Flavor Mixing Mismatch between gauge symmetry and particle spectra = s d s d cs cd us ud CP iolation Complex elements not removable by the phase convention = θ θ θ θ δ δ δ δ cos sin sin cos s d c u i i cs cd us ud i i e e e e 0 0 0 0
( ) ( ) 1 1 2 1 2 1 2 3 2 2 3 2 λ η ρ λ λ λ λ η ρ λ λ λ A i A A i A tb ts td cb cs cd ub us ud b t s c d u = b s d b s d tb ts td cb cs cd ub us ud An imaginary number parameter violates CP CP Paper with Maskawa 6-Quark Model
CP Paper with Maskawa 1974 Discovery of J/ψ 1975 Discovery of τ -lepton c-quark 1975 S. Pakvasa, H. Sugawara 1976 J.R Ellis, M-K Gaillard, D. Nanopoulos 1977 Discovery of Υ 1995 Discovery of t-quark b-quark Large CP violation in the B-meson system 1980 Carter, Sanda 1981 Bigi, Sanda B-Factory d : bd bu B d B : B u: : B u db ub B-Mesons
E(e )=8Ge, E(e + )=3.5Ge Finite angle beam crossing Feature E(e )=9Ge, E(e + )=3.1Ge Zero angle beam crossing 1994 1993 May 1999 still running May 1999 Apr. 2008 L peak = 1.7 10 34 /cm 2 /s Friendly competition of two experiments over a decade L peak = 1.2 10 34 /cm 2 /s
PeP-II BaBar
Belle: 14 countries, 59 institutes, about 400 researchers
Experimental erification at B-Factories
Experimental erification at B-Factories Present Status of CP iolation B-factory results show that quark mixing is the dominant source of CP violation B-factory results allow room for additional source from new physics Matter dominance of the Universe seems requiring new source of CP violation
Lepton Flavor Mixing Discovery of neutrino oscillation at Super-Kamiokande using atmospheric neutrinos Atmospheric Neutrino θ Multi-Ge μ-like + PC Super-K 1996~ Earth ν C.R. J.Raaf, Talk at Neutrino 2008 Courtesy of KEK Yoji Totsuka 1942-2008
Lepton Flavor Mixing Number of events events/0.25[ge] 18 16 14 12 10 8 6 4 K2K experiment ν μ : KEK-PS fit_out.0x03.cmb.free.1.shape Entries 58 1R-μ spectrum No oscillation Oscillation KamLAND experiment ν e : reactor 2 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 [Ge] 1 2 3 4 Eν rec ν μ disapearance ν e disapearance
Lepton Flavor Mixing T2K experiment ν μ created at JPARC Super-K Aiming to discover ν e appearance