1

DisclaimerDisclaimer • This talk is not for B physics experts.

Taipei101

If you did it, you may check e-mails during my talk.

B0

B0

22 ( ( and and 33 ( ())

Masashi Hazumi (KEK)

3rd International Conference on Flavor Physics (ICFP2005), October 3-8, 2005

1 “beam”1 “beam”

2 “banana”2 “banana”

3 “fan”3 “fan”

3

Motivation for Motivation for 22 and and 33 measurements measurements

• Overconstrain the CKM unitarity triangle– important test of Kobayashi-Maskawa mechanism of CP violation– one of the main physics goals of BaBar and Belle

• Overconstrain the CKM unitarity triangle– important test of Kobayashi-Maskawa mechanism of CP violation– one of the main physics goals of BaBar and Belle

1 “beam”1 “beam”

2 “banana”2 “banana”

3 “fan”3 “fan”

4

Principle of measurementPrinciple of measurement

• 2 from time-dependent CP asymmetries

• 3 from direct CP asymmetries

1 “beam”1 “beam”

2 “banana”2 “banana”

3 “fan”3 “fan”

(other methods exist but are not competitive)

5

MethodsMethods

• Interestingly, at present best results on 2 and 3 are obtained by methods proposed after B factories started taking data.

• Interestingly, at present best results on 2 and 3 are obtained by methods proposed after B factories started taking data.

• In reality, you need• two diagrams with different weak phases (CP-odd phases) and strong

phases (CP-even phases)

• two amplitudes with similar size ( |A1/A2| = r > O(0.1) )

• precise measurements (knowledge) on and r

• sufficient signal yields with good (tolerable) background level

A1/A2=|A1/A2|exp(i)exp(i) CP |A1/A2|exp(i)exp(i) A1/A2=|A1/A2|exp(i)exp(i) CP |A1/A2|exp(i)exp(i)

6

Mixing-induced CP violation (CPV) and Mixing-induced CP violation (CPV) and 2 2 (())

13

2VudV*ub

VtdV*tb

VcdV*cb

B0

d

b–

d–

bt

–tB0

–V*

tb Vtd

V*tbVtd

Mixing diagram Decay diagram (tree)

B0

b–

d du–

d–u

/

/Vud

V*ub

7

Mixing-induced CP violation (CPV) and Mixing-induced CP violation (CPV) and 2 2 (())

B0

B0 (

B0

E (GeV)Events/(0.02GeV)

666±43 signals from275 million BB pairs

Small |Vub| = (4.38 0.19 0.27 ) 10

3

measurements still limited by statistics

B0

b–

d du–

d–u

/

/Vud

V*ub

8

Mixing-induced CP violation (CPV) and Mixing-induced CP violation (CPV) and 2 2 (())

B0

B0 (

B0

Small |Vub| = (4.38 0.19 0.27 ) 10

3

measurements still limited by statistics

617±52 signals from232 million BB pairs

signal-enhancedregion

B0

b–

d du–

d–u

/

/Vud

V*ub

9

made by H. Miyake

Time-dependent CP violation in BTime-dependent CP violation in B00

(A = C )

(CP = +1)

Mixing-induced CPVMixing-induced CPV Direct CPVDirect CPV

With the tree diagram only

S = sin22

A = 0

10

Tough (Tough () bananas: penguin pollution) bananas: penguin pollution

• Compelling evidence for direct CPV

• Large penguin diagram (P) ~ Tree diagram (T)

• Large strong phase difference between P and T

B0d

d

b

du

u

W

g +

-

VtdV*

tb

t d

A

S

4.0direct CPV4.0direct CPV

2222 )2sin(1 effeffAS 2222 )2sin(1 effeffAS

11

Isospin analysis: flavor SU(2) symmetryIsospin analysis: flavor SU(2) symmetry

• Model-independent (symmetry-dependent) method• SU(2) breaking effect well below present statistical errors

2222 )2sin(1 effeffAS 2222 )2sin(1 effeffAS

12

22 ( () from B ) from B

inputsB(+0) = (5.5 0.6)B(+-) = (5.0 0.4) 10-6

B(00) = (1.5 0.3) A(00) = +0.28 0.4S(+-) = 0.50 0.12A(+-) = +0.37 0.10

inputsB(+0) = (5.5 0.6)B(+-) = (5.0 0.4) 10-6

B(00) = (1.5 0.3) A(00) = +0.28 0.4S(+-) = 0.50 0.12A(+-) = +0.37 0.10

larger than expected big impact on 2 determinationlarger than expected big impact on 2 determination

13

Isospin analysis with BIsospin analysis with B00

• Even worse on first sight ...– Dirty final state: – Mixture of CP = +1 and 1: need to know each fraction

(A++A-)/√2

A||

(A+-A-)/√2

A⊥

A0

+

+A0

A+

A-

+1

1

1

CP

vector vector

14

BB00 longitudinal polarization from helicity distributionlongitudinal polarization from helicity distribution

total background

fL= 0.951 0.0290.031

0.0330.039 fL= 0.978 0.0140.020

0.028

CP(A++A-)/√2

A||

(A+-A-)/√2

A⊥

A0

+

+A0

A+

A-

+1

1

1

~purelyCP = +1 !~purelyCP = +1 !

15

22 ( () from B ) from B

2A00

A+-/ 2

squashed triangle small

Inputs to isospin analysisB(+0) = (26 6)B(+-) = (26 4) 10-6

B(00) < 1.1 A(00) = N.A.S(+-) = 0.22 0.22A(+-) = 0.02 0.17

Inputs to isospin analysisB(+0) = (26 6)B(+-) = (26 4) 10-6

B(00) < 1.1 A(00) = N.A.S(+-) = 0.22 0.22A(+-) = 0.02 0.17

the best mode now !the best mode now !

2 = (96 13)º 2 = (96 13)º

(triangle not closed with present central values)

16

Time-dependent Dalitz analysis with BTime-dependent Dalitz analysis with B00

• ArE to try even more involved analysis

s =

m(

)

2

s+=m()2

+

+

+

Isospin analysis isolate penguin and restore the simplicityDalitz analysis accept complication and dare to utilize Breit-Wigner phasesIsospin analysis isolate penguin and restore the simplicityDalitz analysis accept complication and dare to utilize Breit-Wigner phases

is for strong/CP-even phase difference. Breit-Wigner phases from .

Amplitudes should be large enough for good statistics. similar to

ratios between amplitudes

Determined by Dalitz fit

Experimentally favored (e.g. high efficiency, small background)

Not so great but tolerable

Snyder-Quinn 1993

17

2 = (113 6)º 2 = (113 6)º +2717

22 ( () from B) from B00

No discrete ambiguity in 0-180 deg. ! Important in the future.No discrete ambiguity in 0-180 deg. ! Important in the future.

18

22 ( () from B ) from B

19

22 W.A. W.A.

CKM (indirect)

All W.A.

20

Direct CP violation and Direct CP violation and 3 3 (())

13

2VudV*ub

VtdV*tb

VcdV*cb

u

b

u

uc

sW

B+d

D0

Vcs

V*ub

fCOM

3 u

b

u

su

c

W

B+d D0

+Vus

V*cb _

fCOM

3

B D(*)K(*)B D(*)K(*)

Choice of fCOM very imporant !Choice of fCOM very imporant !

Color suppressed Color allowed

21

AArErE to measure to measure 3 3 (1) GLW(1) GLW

fCOM = DCPfCOM = DCP

[PLB 253,483; 265,172(’91)]

+-/ +- (CP=+1) , S0/..(CP= 1)

Gronau-London-Wyler

-1.0 0.0 1.0 0.0 1.0

ACP=, RCP= rB, B, 3 need more statisticsneed more statistics(four observables, three unknowns)

O∆∆O score

22

AArErE to measure to measure 3 3 (2) ADS(2) ADS

fCOM = DDCSDfCOM = DDCSD

Atwood-Dunietz-Soni

Not yet observed,but important limit on rB

already available

Not yet observed,but important limit on rB

already available

OX∆O score[PRL 91,171801(’03)]

color suppresed

Cabibbo suppresed

23

AArErE to measure to measure 3 3 (3) Dalitz(3) Dalitz

• fCOM = Ks

OO∆O score Giri-Grossman-Soffer-Zupan

[PRD 68,054018(’03)]

B+:

B-:

m+=m(Ks+), m=m(Ks) CPV: Asymmetry in Dalitz dist.:

r

r |A2|

|A1|r =

2m

2m

0 D 2m

2m

0 D obtainfromtagged D0

(D*+ D0+)sample

24

Signal yieldsSignal yields

232M BB232M BB

275M BB275M BBD0K*

D0KD*0K[D00]209

signals58signals 36

signals

49 signals

90 signals282 signals

[hepex/0504039]

[hepex/0411049] [hepex/0504013]

E E E

25

Dalitz Plots: Dalitz Plots: DD00KK

232M BB232M BB

275M BB275M BB B+ B

B+ B

26

33 Fit Results Fit Results

-100 0 100

0

0.1

0

.2

0.3

3(deg)

rB

-100 0 1000

0

.1

0.2

0

.3

rB

3(deg)

D0K*D0K D*0K [D00]

D0KD*0K [D00]

3 = (68 13 11model )º 3 = (68 13 11model )º +1415

3 = (67 28

13 11model )º

3 = (67 28

13 11model )º [hepex/0507101]

[hepex/0411049]

27

33 ( () from B ) from B D D(*)(*)KK(*)(*)

3 = (63 )º 3 = (63 )º +1512

28

Unitarity Triangle with Angle MeasurementsUnitarity Triangle with Angle Measurements

1 = (22 1)º 2 = (99 )º3 = (63 )º

+138+1512

1 + 2 + 3

= (184 )º+2014

(naïve sum by the speaker)

29

All combinedAll combined

ρ = 0.216 ± 0.036 η = 0.342 ± 0.022

30

SummarySummary• Recent remarkable progress in 2 and 3 measurements

– Now overconstraining CKM just from angle measurements (i.e. from CP asymmetries alone !)

• O(10º) achieved using new ideas !– for 2, DK Dalitz for 3 – Still limited by statistics

• Improvements in the future guaranteed

• To compete with the 1 precision, we need– better understanding of hadronic uncertainties

• SU(2) breaking• Dalitz amplitudes, amplitude ratios, etc.

– much more data LHCb, Super B factory

1 = (22 1)º 2 = (99 )º3 = (63 )º

+138+1512

31

Backup SlidesBackup Slides

32

33

34

buW

B0

+Vud

Vcbc

d

D*

dd

bcW

B0 +

Vcd

Vubu

dD*

dd

(B0→D) ~ 1 + cos(mt) – Ssin(mt)

(B0→D) ~ 1 + cos(mt) S sin(mt)

(B0→D) ~ 1 cos(mt) S sin(mt)

(B0→D) ~ 1 cos(mt) S sin(mt)

Cabibbo favored

Cabibbo suppressed

CP

CP

S = 2(1)LR sin(213 ) : hadronic phase, R = ~0.02

ACF ADCS

mixing mixing induced CPV

[L=0 (D), 1(D) R, not same for D and D

sin(2sin(211++33): B): B00DD(*)+(*)+-- TCPV TCPVsin(2sin(211++33): B): B00DD(*)+(*)+-- TCPV TCPV42

[I.Dunietz, PLB 427,179(’98)]

B0→mixing

ADCS

ACF

35

t Distributionst DistributionsB0 D

10.6K cand.(96% purity)

B0 B0

152M BB152M BB232M BB232M BBpartial reconstruction

B0B0

D

CPCP

Full recon.

-10 -5 0 5 10 -10 -5 0 5 10t(ps)

89.3K signals

Good tagLepton tag

background

D

D D

[hepex/0504035] [PRL 93,031802(04)]

D D

D D

36

sin(2sin(211++33): Summary): Summary

D*

D

D

(c~0 if ~0 or 180 deg.)

37

Extraction of Extraction of 33??

estimated formB (B Ds

)[SU(3) symmetry]

No significantconstraint yet !

R