CP Violation and Flavor Mixing Makoto Kobayashi KEK and JSPS Plan - - PowerPoint PPT Presentation

CP Violation 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 Verification at B-factories
• 5. Lepton Flavor Mixing

Introduction to the Standard Model

d d u u d u Proton（p） Neutron（n） Nucleus Atom Electron p n

Fundamental Particles Quark Lepton

u d c s t b e

μ τ

νe νμ ντ

u d c s t b

Fundamental Interactions

• Strong Interaction
• Electro‐Magnetic Interaction
• Weak Interaction

QCD

Introduction to the Standard Model

Weinberg‐Salam‐Glashow Theory

Established in 1970’s ・ Development of gauge theory 1971 ‘t Hooft ・ Discoveries of new flavors e

μ τ

νe νμ ντ

u d c s t b

After 1970

1964 Gell‐Mann quark model u, d, s Introduction to the Standard Model

Electro‐Magnetic Interaction Strong Interaction Weak Interaction

1973 Kobayashi Maskawa Six‐Quark Model

1947∼ Discovery of Strange Particles

Sakata and His Group

Shoichi Sakata

1911-1970

1956 Sakata

Λ , , n p

: Fundamental Triplet Sakata Model

Λ

±

π n p

Λ K K ±

±

Ξ Σ Λ

Strange Particles

All the hadrons are composite states of

Courtesy of Sakata Memorial Archival Library

Hadron : strongly interacting particle

Weak Interaction in the Sakata Model

p

Λ n

ν

μ e

1959 Gamba, Marshak, Okubo 1960 Maki, Nakagawa, Ohnuki, Sakata

μ ν

+ + +

= Λ = = B e B n B p , ,

Nagoya Model : B‐L Symmetry

Sakata and His Group

ν Λ ν β + + → + + →

− −

e p e p n paticle strange decay

1962 Discovery of Two Neutrinos

μ

ν ν e

μ e

1962 Maki, Nakagawa, Sakata

2 1

ν μ Λ ν

+ + + +

= = = = B p B e B n B p ' , , ,

μ μ

ν θ ν θ ν ν θ ν θ ν cos sin sin cos

e 2 e 1

+ − = + =

Neutrino Oscillation 4th Fundametal Particle (GIM scheme)

1962 Katayama, Matumoto, Tanaka, Yamada Sakata and His Group

Lepton Flavor Mixing

MNS Matrix

1971 Niu et al. Evidence for the 4th element?

Emulsion Technique

• Applied to accelerator exp.
• Life time measurement of

the new flavors

Cosmic Ray Events

Sakata and His Group

Some Japanese groups began to investigate the four-quark model

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 Violation 1964 Cronin et al.

ππ →

L

K CP Paper with Maskawa

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 V V V V s d

cs cd us ud

CP Violation

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 V V V V e e

( ) ( )

⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎝ ⎛ − − − − − − − ≈ ⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎝ ⎛ 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 V V V V V V V V V

tb ts td cb cs cd ub us ud

⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ′ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ′ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ ′ b t s c d u

⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎝ ⎛ ⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎝ ⎛ = ⎟ ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎜ ⎝ ⎛ ′ ′ ′ b s d V V V V V V V V V 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

• 1974 Discovery of J/ψ
• 1975 Discovery of τ -lepton
• 1977 Discovery of Υ

c-quark b-quark

Large CP violation in the B-meson system

1980 Carter, Sanda 1981 Bigi, Sanda

B-Factory

CP Paper with Maskawa

1975 S. Pakvasa, H. Sugawara 1976 J.R Ellis, M-K Gaillard, D. Nanopoulos

• 1995 Discovery of t-quark

d b b d u b b u

:

d

B

:

d

B :

u

B :

u

B

B-Mesons

E(e−)=8GeV, E(e+)=3.5GeV Finite angle beam crossing E(e−)=9GeV, E(e+)=3.1GeV Zero angle beam crossing

Feature

1994 1993

May 1999 – still running May 1999 –

• Apr. 2008

Friendly competition of two experiments over a decade

Lpeak = 1.7×1034/cm2/s Lpeak = 1.2×1034/cm2/s

PeP-II BaBar

Belle: 14 countries, 59 institutes, about 400 researchers

Experimental Verification at B-Factories

Experimental Verification at B-Factories

Present Status of CP Violation B-factory results show that quark mixing is the dominant source of CP violation Matter dominance of the Universe seems requiring new source of CP violation B-factory results allow room for additional source from new physics

Discovery of neutrino oscillation at Super-Kamiokande using atmospheric neutrinos

Super-K 1996～ ν Earth C.R. θ

Atmospheric Neutrino

J.Raaf, Talk at Neutrino 2008

Multi-GeV μ-like + PC Lepton Flavor Mixing

Courtesy of KEK

Yoji Totsuka

1942-2008

K2K experiment

Eνrec Entries 58

fit_out.0x03.cmb.free.1.shape

[GeV] events/0.25[GeV]

2 4 6 8 10 12 14 16 18 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Oscillation No oscillation 1R-μ spectrum 1 2 3 4 Number of events

Eνrec Entries 58

fit_out.0x03.cmb.free.1.shape

[GeV] events/0.25[GeV]

2 4 6 8 10 12 14 16 18 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Oscillation No oscillation 1R-μ spectrum 1 2 3 4 Number of events

νμ : KEK-PS

KamLAND experiment

νe： reactor

νμ disapearance νe disapearance

Lepton Flavor Mixing

νμ created at JPARC Super-K Aiming to discover νe appearance

T2K experiment

Lepton Flavor Mixing