1#

CKM Unitarity anglesand

Recent results from the B factories.)

Hassan JawaheryUniv. of Maryland

Lepton-Photon SymposiumFermi National Accelerator Laboratory

August 12, 2003

Outline• Introduction & definitions • Experimental observables related to and • Experimental results, some discussion of

implications for SM & constraints on and

2#

| |V Vc d c b

V tdV ub*

*

*td tb

cd cb

V VV V

*

*ud ub

cd cb

V VV V

0VVVVVV *tbtd

*cbcd

*ubud

112/1

2/1

23

22

32

AiAA

iAVCKM

The Unitarity Test

CPDefinitions

)arg(

)arg(

)arg(

*

*

*

*

*

*

cdcb

cdub

tdtb

cdcb

udub

tdtb

VVVV

VVVV

VVVV

Both involve Vub

3#

Constraints from the CKM fit |Vub|, |Vcb|, K, md , ms

oo

o

o

o

o

8037

12277

5.264.19

At 95% C.L.

Unitarity Tests : Search for deviation from SM

Using direct measurements of angles check: ++

Check if B Decays are consistent with the range of angles from the CKM fit?

Indirect info on angles

A. Hoeoecker et al, Eur. Phys. Jour.

C21 (2001) 225, [hep-ph/0104062]

4#

b uu

sd ,

W

a1….

Tree diagrams are not alone:

b uu

sd ,

W

..

CKM suppressed

Penguins (gluonic & E.W) can also lead to the same decays:

W

tb sd ,

u

u

g

Main source of info on and Decays involving bu transitions

Data indicate gluonic penguins are large & complicate extraction of

I- Charmless B Decays

Interference of T & P results in Direct CP violation & sensitivity to

d

s

5#

b uW

sc

+

KDB 0

KDB 0

B- DCPK-

II- Decays involving interference of bu W- & bc W- Processes

(Penguin Free)

bW

s

cu

Involves arg(Vub)=

BDK:

dependence of rate and direct asymmetry

B0D

c0B

d

bu

d

*D

d

bc

d 0B

u

*D

0B

d+

Direct CP asymmetry sensitive to sin(2

arg(Vub)=

Same final state via B0 mixing & bu

6#

Experimental Observables

With Tree and Penguins both in action:

γδ |TP

|cpA

|TP

|γδ | TP

|Br

)iδ|P|eiγ(|T|eA)iδ|P|eiγ(|T|eA

sinsin2

2coscos21

To constrain requires estimates of:

| P/T|& relative strong phase

Branching fractions for various non-charm B decays

Time Integrated (Direct) CP asymmerties

)fΒΓf)ΒΓf)ΒΓ)fΒΓAcp

7#

More observables: Time – Dependent CP Asymmetries

2sin(&02**

**

SCeVVVVVVVV i

udubtdtb

udubtdtb

With Tree alone

2

2

11

||||

fC21

2||)Im(

fS

Time evolution of tagged B0 decays, e.g. in the case of B0

)]tmcos(C)tmsin(S1[4e)t(f dfdf

)/t(

CPV due to mixing and decay interference

Direct CPV in Decay )()(

pq

0

0

fBAfBA

iγeiδe|TP|1

iγeiδe|TP|1

2ieλ

With Penguin and TreeS=sin2eff

eff –

C 0

Belle: Af = - Cf (BaBar)

8#

A few comments on the already established pattern from charmless 2-body decays

Connected via Isospin symmetry (Gronau &London) (Isospin engineering)

00 ππππ~ BABA

ππ~2

1 0BA

ππ2

1 0BA

000 ππBA

000 ππ~BAππ

With Tree alone,expect:

%5

KB

4

KB

Measurements:

Penguins are significant players

P’ & use SU(3)connections to estimate P

(P’ & T’)

(P’)

(P & T)(P & T)

(T)

(P’ & T’)(P’ & T’)

Control rescattering effects

Constructing these triangles is a major goal of the experiments

9#

Goals and Issues on the Measurement Side

The reality (Considering the presences of large Penguin effects)

No single measurement is expected to lead to determination of &

Need info from many decay modes and the emerging pattern & connections via symmetries, [isospin, SU(3) ], and eventually more predictive theories [perhaps QCD factorization or perturbative QCD- when verified ] to constrain various components of the problem.

Search for CP violation: Direct (C 0) & Indirect (S0) deviating from (sin2ie. indirect CPV outside of mixing phase.]Measure/Constrain using many different modes and exploit the redundancy to resolve the ambiguities.

Keep finding the pieces of the charmless puzzle

The job description Eventually

10#

Experiments and Data Asymmetric e+e- B Factories:Physics coverage : Bd & Bu Decays

BaBar at SLAC PEP-II Machine 113 fb-1 on s) ( 126 fb-1 total)124x106 B B events

Belle at KEK-B Machine140 fb-1 on s) (158 fb-1 total)152x106 B B events

CLEO at the CESR Machine – Some results on Br & direct Asymmetries.The pioneer of the field and the first source of information on B decays,Including observation of charmless decays. [~13 fb-1 on peak]

The B physics reach of hadron machines & current status covered by Kevin Pitts . Next Talk

The focus of this talk

11#

Analysis Issues for Rare B Charmless decays

-Looking for modes with Br~10-6 to 10-5 -Continuum qq(bar) background at 103 larger than the signal BKG Suppression using event shape & topology, kinematics, particle ID,..

Kinematic variables:

E=Ebeam-EB

provides separation of KK,

K, decays

22Bbeam pEMes

Signal Monte Carlo

Other info into analysis:

t=z/<c

Flavor tag of other side

Particle ID, event shape,..

12#

The road to Measurement of CPV in B

K

BaBar: 81 fb-1 Belle 78 fb-1

K

Isolation of Signals

B

Per experiment

K

13#

Time Dependent CPV in B

(BaBar)

Asy

mm

etry

E

vent

s/1p

s

(Belle)

5-5 0

5-5 0

B0 tag

B0 tag

Fits to: )]tmcos(C)tmsin(S1[4e)t(f dfdf

)/t(

81 fb-1 78 fb-1

04.025.030.005.034.002.0

CS

)(08.027.077.041.023.1 08.0

07.0

ACS

t(ps) t(ps)

14#

New Results:BaBar Update of CPV measurements with full data sample (Run 1+2+3): 113 fb-1 on Peak data

013.0041.0107.005.019.019.003.022.040.0

KACS

4.105.125.373.8730.249.265

KK

K

NNN

Reprocessed Run1+2 (82 fb-1 )

Added Run 3 ((31 fb-1 )

New CPV Results

Run1+2(reprocessed)

S=-0.252±0.27 C=-0.166 ±0.22

Run 3

S=-0.67±0.35 C=-0.33 ±0.34

B0 tag

B0 tag

15#

Summary of CPV in B

Current world average (with BaBar new results)

S=-0.58±0.20 C=-0.38 ±0.16

Too early to claim observation of CPV in B Direct (in decay) or Indirect(mixing &

decay)

Belle’s update with their full data set awaited

S & C not enough to measure

Need eff – , which requires the other pieces of the isospin analysis.

)effα2sin(2C1S&0C

gnoring the large ~2 )

16#

BaBar: The decay B

21431346)(

N 60 103.06.01.2)( BB

Significance: 4.2

Used their full data set (113 fb-1 )

Measured Br(BBr(Bx10-6 ]

Control over a major background source. Br about half of previous assumed value

qq bkgd

Fischer Discriminant

signal

Observation

17#

Belle: The decay B

3.94.86.25)(

N

Analyzed full data set of 140 fb-1

From a fit to 2-dimensional distribution of Mes and E

Find:

Significance:3.4

60 103.06.07.1)( BB

Evidence

18#

Branching ratios (x10-6) Mode CLEO Belle BaBar Average

4.5 4.4 0.6 0.3 4.7 0.6 0.2 4.6 0.4

4.6 5.3 1.3 0.5 5.5 0.6 5.2 0.8

<4.4 1.7±0.6 ±0.3 2.1 ±0.6 ±0.3 1.97 ±0.47

4121.. 50

40..

8161.. 70

60.. 01

90..

What about All but one piece is in place

For a full Isospin analysis need: Cdirect CPV)

&

Still some constraint can be set using the measured average Branching fraction:

)B(B 000 )BB( 000

(Quinn- Grossman),

With WA Br(B

eff | at 90% c.l.

00 ππππ~ BABA

ππ~2

1 0BA

ππ2

1 0BA

000 ππBA

000 ππ~BAππ

Not a very useful limit & don’t expect more than ~10o improvement in future.

0

0002

((sin

BBBB

19#

Summary of measurements of BDecaysSee John Fry’s talk this morning for more detail &comparison with Theory

Thanks to Heavy flavor averaging group(HFAG): Rare decays: J. Smith (colorado), J. Alexander(Cornell), P.Chang (KEK)

03.009.0)(02.016.004.0

)(012.0041.0107.0)(014.0035.0086.0

AverageCLEO

BaBarBelleAK

Evidence Direct CPV ?

20#

What did we learn about

s this all consistent with

Standard Model?

Does it accommodate the range of UT angles from the global CKM fit?

21#

C vs S:

Allowed range & comparison with SM ( CKM fit)

Data consistent with SM (CKM fit)

Gronau and Rosner approach(PRD 093012)|P / T | estimated usingB->K0+ & Bl , B 0+

(with use of SU(3) & factorization)

Here calculate S & C for |P/T|~0.3Unconstrained strong phase

iγeiδe|TP|1

iγeiδe|TP|1

2ieλ

212

||)Im(

fS

2

2

11

||||

fC

BaBar

Physical boundary

Belle

BaBar

My Average

22#

A more optimal use of information using the CKMfitter tools with various assumptions (LAL 02-103: Authors Hoecker, Lacker, Pivak, Roos).

In all scenarios data can accommodate the range of from the SM CKM fit

SU(3) & some use of QCD Factorization to estimate SU(3) breaking effects

23#

Useful ratios of branching fractions and ps-asymmetries with sensitivity to

)()()()(

000000

00

0 21

KBBrKBBrKBBrKBBr

AR

nn

)()()()(

00

00

0

2KBBrKBBrKBBrKBBr

AR

cc

sinsin2

)cos21(cos)(cos21

,,,

0

2,

2,,,

ncncnc

ncncncnc

rA

rqqqrR

000

00

0 B

B

tt

KBBrKBBrKBBrKBBr

AR

)()()()(

Constraints on Connecting the BK data via symmetries

Ratios using HFAG averages:

R0=0.99±0.09 A0= - 0.09 ±0.03

Rc=1.30±0.15 Ac=0.0 ± 0.06

Rn=0.8 ±0.11 An=-0.07 ± 0.03

Rosner, Gronau, Neubert, Fleischer, Mannel, ..

All shown to accommodate range of from CKM fit(Fleischer), (Gronau, Rosner),…

Size of EW penguins|T/P|

24#

1 range of R0

60 < at 1 level

No useful limit at 2 level

Consistent with CKM range: oo 8037

R0

A0=-0.06(A0+1

A0=-0.12(A0-1

Gronau & Rosner method hep/ph-0307095

(R0 vs for fixed A0

R0

25#

Other channels of reaching BCPV studies require isolation of states with specific CP parity: e.g. B ( using Dalitz plot analysis.Interference between (can be used to determine even in the presence of penguins [Quinn-Snyder]

BaBar has presented CPV results based on quasi 2-body decays B0”“B0””updated for this conference with their full data sample.

1st Belle results on CPV with these modes expected soon.Components of the Isospin analysis (pentagon) are also being measured. (J. Fry’s talk today)

B( e.g. Bhas been measured and shown to be dominated by the CP even component – good news for CPV studies.

26#

CPV Studies with the decay B0

Not a CP eigenstate & involves more observables:

Summing over the charge:

Direct CP violation: C

Indirect CP (mixing and decay): S

Charge Asymmetry:

)cos()()sin()(1())(1()(

)cos()()sin()(1())(1()(/||

/||

0

0

tmCCtmSSehAtf

tmCCtmSSehAtf

hhhht

CPh

B

hhhht

CPh

B

)()()()(

hNhNhNhNA h

CP

Dilution (Non CP parameters): C & S

)cos()sin()/( tmCtmSBBA

00

27#

BaBar results on CPV in B: 113 fb-1

N() N() C C S S ACP() ACP()804.2 49.2

260.4 31.4 0.35 0.13

0.20 0.13

-0.130.18

0.33 0.18

-0.110.06

0.18 0.12

)cos()sin()/( tmCtmSBBA

00

28#

2.5 (2.7 if stat. only)

99%

90%98.6%

Define two asymmetries:

CACCACABNBNA

CACCACABNBNA

CP

CPCP

CP

CPCP

1)()(

1)()(

00

00

05.018.0 ,07.052.013.013.0

19.017.0

AA

New Results

04.011.0 ,06.062.017.016.0

28.024.0

AAPRL

2.3 (Stat. only)

Test Of Direct CPV

29#

Quinn-Grossman bound applied to the longitudenal polarization component of the rates:

oeff

LLeff lcBfBf

19||

...%90@10.0)/()(sin 2

The Channel to watch in Future

The components of Bare identifeid: B0(BaBar),B+elle & BaBar)

Decays nealy 100% longitudinally polarized [CP-even]

Limit has been set on B0See John Fry’s talk this morning for more detail

>2 times more restrictive than Bsystem

A promising channel:the B system

30#

Reaching

via

(bu(cs) & bc(us) interference:

BDK DecaysMethod and observables suggested by Gronau, Wyler,Atwood,Dunietz, Soni,Quinn, Sanda

31#

BDK Modes- No penguins

b uW

sc

)( *uscbVV

ii eeAKDBA 2||)( 10

bW

s

cu

12

0 ieAKDBA ||)(

)( *uscbVV

In B- DCPK- , the diagrams interfere & provide the sensitivity to :[DCP=(1/2)(D0 D0 ) ] KKD evenCP , ,.., ssoddCP KKD 0

)()()()(

KDBBKDBBKDBBKDBB

R cpcpcp 00

00

)()()()(

KDBBKDBBKDBBKDBB

Acpcp

cpcpcp 00

00

coscos DKDKDK rr 21 2

coscos

sinsin

DKDKDK

DKDK

rrr

2122

rDK (~0.1 –0.2) & DK

Also unknown

Experimenters are very active in constructing the DK puzzle

Observables

DK triangle

32#

coshel

from P→PV

MK*-

D0 → K, K,K 0

B-→DCP K*-

13.14.34.3

D1=K+K-, +

D2=Ks, Ks, Ks

7.23.6 2.4

B- → D*0 K*-

B → D*0 K*- ALL

D*0 → D0 0 D*0 → D0

B0 → D K0

33#

R1(CP=+1) A1 (CP=+1) R2(CP=-1) A2 (CP=-1)

BaBar 1.06 ±0.26 ±0.17 0.17 ±0.23 ±0.08

Belle 1.21 ±0.25 ±0.14 0.06 ±0.19 ±0.04 1.41 ±0.27 ±0.15 -0.19 ±0.17 ±0.05

Average

BDoK-

Br(x10-4) R1(CP=+1) A1 (CP=+1) R2(CP=-1) A2 (CP=-1)

BaBar 6.3 ±0.7 ±0.4

Belle 5.2 ±0.5 ±0.6 -0.06 ±0.33 ±0.07 0.19 ±0.50 ±0.04

CLEO 6.1 ±1.6 ±1.7

Average

BDoK*-

)KDB( **0B (8.3 ± 1.1(stat) ± 1.0(sys)) x 10-4 & L/0.86 ±0.06 ±0.03 (BaBar)

(7.7 ± 2.2(stat) ± 2.6(sys)) x 10-4 CLEO

Mode Br(x10-5)Belle

Br(x10-5)BaBar

Br(x10-5)Average

B0DoK*0 4.8 ±1.1 ±0.5 3.0 ±1.3 ±0.6

B0DoK0 5.0 ±1.3 ±0.6 3.4 ±1.3 ±0.6

B0D*oK0 <6.6 (90% c.l.)

B0D*oK*0 <6.9 (90% c.l.)

B0DoK*0 <1.8 (90% c.l.)

B0D*oK*0 <4.0 (90% c.l.)

The BDK puzzle under construction

Vub

Vub

34#

What about Current errors are still too large to allow for simultaneous extraction of ratio of (bc) and (bu) amplitudes (rdk) and the strong phase. Need many fold more data. (may be possible with 500 fb-1)

With assumptions on (rdk): mild limits can be extracted. e.g M. Gronau (hep-ph/0306308): at 1 sigma level.

35#

Reaching sin(2

via

(bu(cd) & bc(ud) interference

(& B0 mixing)

B0D(*+) - Method and observables first suggested by Sachs,Dunietz

36#

B0D(*+)- Modes

c0B

d

bu

d

*D

Dominant diagram b c transition

d

bc

d 0B

u

*D Suppressed diagram b u transition

0B

b

d

*||)( udcbi VVeADBA 2

10 i

ubcdi eVVeADBA ||||)( *

20 2

)}sin()cos(1{),(

)}sin()cos(1{),(|0

|0

tmStmCNetDBP

tmStmCNetDBP

ddt

ddt

Time evolution:

2sin(1

22r

rS2

2

11

1rCr

02.0)()(

0

0

DBADBAr Small asymmetry expected

37#

BaBar

II - Fully reconstructed

B0D(*+)- Decays

Lepton tags kaons tags

0 0

0 0

tag tag

tag tag

B BCP

B B

N N

N N

A

Belle Fully reconstructed B0D(*+)- Decays

lDrlDrlDrlDr

DD

DD

DD

DD

*(036.0013.0056.0022.0)2sin(2*(036.0013.0059.0094.0)2sin(2*(036.0016.0056.0033.0)2sin(2*(036.0016.0059.0092.0)2sin(2

**

**

**

I- Partially reconstructed B0D*+- Decays: (number of events)

035.0068.0025.0sin)2cos(2021.0038.0022.0cos)2sin(2035.0070.0031.0sin)2cos(2021.0038.0068.0cos)2sin(2

**

**

DD

DD

DD

DD

rrrr

017.0025.0064.0cos)2sin(2 ** DDr

2

38#

(*)

(*)

0 (*)

(*) 0 (*)

( )( )

S

s cd D

cs D

fBr B D VrBr B D V f

Use measurements of B0D(*+)sto

estimate r(*) (Factorization & SU3 correction )

0.004 * 0.0050.005 0.007( ) 0.021 ( ) 0.017r D r D

sin(2 ) 0.89 @ 68.3% C.L.

sin(2 ) 0.76 @ 90% C.L.

Interpretation:BaBar’s attempt

Favors the CKM favored solution to sin

39#

Summary & Conclusions Major progress made in probing the charmless sector of B decays for

information on unitarity angles New updated measurements of CPV in B still show no

significant evidence for CP violation in this mode.

Observation of B – a missing component of Tree/Penguin disentanglement plan. CPV studies in Bshows hints of direct CP violation. The decay is now measured and looks promising for CPV

studies and constraining . Indications that penguins are smaller. Indication of direct CPV in BWA: Belle, BaBar, CLEO) No indication for large direct CP yet. The emerging constraints on the angles from the pattern of data are

consistent with the favored range from the CKM picture in the Standard Model.

Penguin free modes (BDK & D* are beginning to contribute to constraints on CKM parameters & many new BDK modes identified.

Much more data & major progress in theoretical understanding of hadronic B decays needed to complete the picture and conclusively perform the CKM unitarity test.