B . Golob, University of Ljubljana 4 Seas Conference 2004, Istanbul

B. Golob, University of Ljubljana 4 Seas Conference 2004, Istanbul

Overview of (selected) Belle and BaBar results

B. Golob, Belle Collaboration University of LjubljanaJožef Stefan Institute, Ljubljana

Introduction Experimental environment overview CKM Matrix

Phase - 1() - 2() - direct CPV Magnitudes - |Vub| Hadron spectroscopy

New charm states much more… Conclusions

Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb

(0,0) (0,1)

Introduction


BaBar & Belle (Ba/lle) main task: CP violation in system of B mesons

specifically: various measurements ofcomplex elements of Cabbibo-Kobayashi-Maskawa matrix

CKM matrix is unitary

deviations could signal processes not included in SM (NP)

W±qi

qjVij

1-2/2A3(-i)

A21-2/2-

1-A2A3(1--i)

=

VudVub*

VcdVcb*

VtdVtb*

VcdVcb*


Experimental environment Asymmetric B factories

~1 km in diameter

Mt. Tsukuba

KEKBBelle

Υ(4s)e+ e-

BaBar p(e-)=9 GeV p(e+)=3.1 GeV =0.56

Belle p(e-)=8 GeV p(e+)=3.5 GeV =0.42

B

Bz ~ cB ~ 200m

Lpeak=

=13.9x1033

s-1cm-2

253 fb-1

274 M BB

Lpeak=

=9.2x1033

s-1cm-2

221 fb-1

239 M BB√s=10.58 GeV

Υ(4s)

http://kekb.jp/


Experimental environment-detectors

Belle SVD:~55m (SVD1)~40m (SVD2)combined

particle ID

(K±)~85%

(p±→K±)<~10%

@ p<3.5 GeV/c

/ KL detection 14/15 lyr. RPC+Fe

Central Drift Chamber small cell +He/C2H5

CsI(Tl) 16X0

Aerogel Cherenkov cnt. n=1.015~1.030

Si vtx. det. 3 lyr. DSSD

TOF conter

SC solenoid 1.5T

8 GeV e-

3.5 GeV e+

z-imp.param. resolution

BaBar:DIRCCherenkovangle

p


CKM Matrix – phasesMeasurement method

)cos()sin(

),,(),,(

),,(),,(00

00

tmAtmS

tfBBBPtfBBBP

tfBBBPtfBBBPa

CPCPtagCPCPtag

CPCPtagCPCPtag

CP

BCP

Btag

J/

Ks

+-

-

+

K-l-

Fully reconstruct decayto CP eigenstate

Tag flavorof other B from chargesof typicaldecay products

t=z/c

Determine time between decays

CPV manifests as an asymmetry in time dependent decay rates

SM: for b → ccs : S=sin21, A=0

Υ(4s)

1

determinedB0(B0)

B0 or B0


CKM Matrix – sin21

22 )()2( iCMbc pEM 2CMi EEE

Nsig=4150

to isolate B→fCP decays from bckg.

B→J/ Ks

274M BBT. HiguchiICHEP’04

227M BBM.BruinsmaICHEP’04

B→J/ KL

J/ψ KL signalJ/ψ X backgroundNon-J/ψ background

BABAR

Nsig=2788

determine tdistribution



t [ps]-8 8

Difference betweenB0 and B0 tagged decays

Miss-tagging probabilityw reduces asymmetry by 1-2w

Expected t distributionconvolved with detectorresolution function

S=sin21= 0.666 ± 0.046T. Higuchi,ICHEP’04Belle

S=sin21= 0.722 ± 0.040 ± 0.023M.Bruinsma,ICHEP’04BaBar

(A=0 fixed)

(A=0.023 ± 0.031)

aCP

Btag=B0Btag=B0

1



B0 →

S = √(1-A2)sin22eff

A ~ sinPfunction of 2 1 P |P/T|

Constraint: SU(2) symmetryM+0 = 1/√2 M+- + M00

M-0 = 1/√2 M+- + M00

b

d

W+ ud

d

uB0

T ~ Vub*Vud ~ 3

+

-

S=sin22

A=0

b

dd

uu

d

b

d

W+

u

ud

d

P ~ Vtb*Vtd ~ 3

tB0+

-B0

0

0W+

Tc ~ Vub*Vud

2



152M BB PRL93,021801(2004)

good tag

B0 →

S+-= -1.00 ± 0.21 ± 0.07A+-= 0.58 ± 0.21 ± 0.07

S+-= -0.30 ± 0.17 ± 0.03A+-= 0.09 ± 0.15 ± 0.04

227M BB Babar,M.Cristinziani,ICHEP’04

-A+-

S+-

M.A.Giorgi,ICHEP’04

B0 →

B0 →

aCP

t [ps]

Nsig=232Nsig=467



B0 →

Mbc[GeV]

Br(B0→00)=(1.17 ± 0.32 ± 0.10)x10-6

ACP= 0.12 ± 0.56 ± 0.06

227M BB Babar,M.Cristinziani,ICHEP’04

274M BB Belle,Y.Sakai,ICHEP’04

Br(B0→00)=(2.32 ± 0.45 ± 0.20)x10-6

ACP= 0.43 ± 0.51 ± 0.17

Similar analysis as for B → also forB → (2eff closer

to 2)

S+- Br(B0→00)A+- Br(B0→+-)ACP Br(B+→+0)

Ba/lle BaBar

Similar from B → Ba/lleSimilar from B →

2= 106o ± 8o11o


Nsig=61

Nsig=82

CKM Matrix – direct CPV


)cos()sin( tmAtmSaCPf ≠0 direct CPV;

|M(B→f)| ≠|M(B→f)|only when multipleproc. contribute to f(tree+penguin)

Belle B→+- first evidenceA+-= 0.58 ± 0.21 ± 0.07not confirmed by BaBar

Direct CPV also in time integrated decay rates:

)()(

)()(

fBfB

fBfBCP

A

5.20 5.24 5.28 Mbc

B0→K-+

B0→K+-

ACP= -0.133±0.030±0.009

ACP= -0.101±0.025±0.005

BaBar,227M BB,M.A.Giorgi,ICHEP’04

Belle,274M BB,Y.Sakai,ICHEP’04Nsig=2139

Nsig=1606

CKM Matrix – consistency


Many independent measurementsUnitary

|Vub/Vcb|

B

Xc,u

l

W

From tree-level (s.l.) B decays

b

c,u

|Vcb| known to ~1.4%,becoming as precise as|Vus|= (~1%)

need to pin-down |Vub|, present WA acc. ~10%b→cl backg. order of magnitude larger

CKM Matrix – |Vub|


l

El

q2

MX

B

Variables separating b → ul from b → cl lepton energy El; hadronic inv. mass Mx; leptonic inv. mass q2;

B1

B2

(4s)

D

K

l

Xu

fully reconstructed (Mbc )

To reduce theoretical uncertainty in Br(b→ul) ↔ |Vub|use combination Mx - q2

Full reconstructionBelle: B→D(*)- +/+/a1

+/Ds(*)+

~0.25%BaBar: B→D(*)- n1 n2K …~0.4%

Babar,88M BBhigh p lepton

Mbc[GeV]

|Vub|

CKM Matrix – |Vub|


Extract signal in high q2 low Mx region:

Babar-CONF-04/11,ICHEP’04

Mx<1.7 GeV

Belle,152M BBT.Iijima,ICHEP’04

q2>8 GeV2

signal

b→cl

|Vub|= (4.98 ± 0.40 ± 0.39 ± 0.47)x10-3

|Vub|= (5.54 ± 0.42 ± 0.50 ± 0.55)x10-3

Babar

Belle (stat.) (syst.) (th.)

Nsig~115 Nsig=174

CKM Matrix – back to sin21


1

Not only from b → ccs (B→ J/ Ks)

b

d

W+

s

ss

d

P ~ Vtb*Vts ~ A2

tB0

KSalso from b → sss (B→ Ks)

other proc. negligibleS=sin21

B→Ks

sin21 = 0.06 ± 0.33 ± 0.09

aCP

2.2 away from ccsNsig=139

sin21 = 0.50 ± 0.25 ± 0.06

Belle, 274M BB, Y.Sakai,ICHEP’04

BaBar,227M BB,A.Hoecker,ICHEP’04Mbc

t

(0.73±0.04)

CKM Matrix – back to sin21


other examples of b → sss (e.g. B → ’ Ks)

0.41±0.110.34±0.21

0.73±0.04

conservativeupper bound:|SKs-S’KS|<0.2

Grossman et al.

“sin21”

S’KS or SKS at present value would be sign of NP

Ks

’Ks

J/ Ks

Conclusions


Num. of hep-ex

0

50

100

150

200

250

1994 1996 1998 2000 2002 2004

year

Aleph+Delphi BaBar+Belle

2000.5

2001

2001.5

2002

2002.5

2003

2003.5

2004

2004.5

1960 1970 1980 1990 2000 2010

year

year

CPV in Ksystem

new charm states

direct CPV inB system

Ba/lle mature exp., testing SM with high precision 1964: CPV in K system, 2001: CPV in

B system 2004: sin21() is a precision measurement (±6%) 1999: direct CPV in K system, 2004: direct CPV in B

system; CKM predictions confirmed 2() measured many measurements stat. limited, in 2 years ~2x more

data

J/(c quark)

CPV in B system

direct CPV inK system

Conclusions


Before (B-factories)…:

…and today…

Hadron spectroscopy – X(3872)


Belle observed a new statedecaying into J/

X(3872)

’

B+→K+ X(3872)

J/

l+l-

M(J/ )- M(J/) [GeV]

confirmed byCDF,D0,BaBar

Belle:(X→c1)/(X→ J/ )<0.89(X→c2)/(X→ J/ )<1.1

X(3872) not observed in anyother decay modeMass, width, Br’s & helicityun-compatible with expected cc states

X(3872)MD*+MD

2MD

c

J/

c0

c1

c2hc

’

c’’

hc’

c1’ c2

Isospin 0++ allowed

Isospin 1-- violating

Decay to J/ +-

< 1 MeV/c2

Hadron spectroscopy – X(3872)


Search for B+→K+ X(3872)

J/

N=10.0±3.6 S/N=5

mass region

M()+M(J/)=3879 MeVX(3872)→J/could occurvia virtual

Belle,274M BBF.Fang,ICHEP’04

in accordance with DD* molecule model

(J)/(J/ )=0.8±0.3±0.1

Swanson,PLB 588,189(2004)

Hadron spectroscopy – DsJ mesons


BaBar and Cleo discovered two narrow resonancesDsJ(2317)+ → Ds

+0 DsJ(2460)+ → Ds+, Ds*+0

BaBar, 125fb-1,V.Halyo,ICHEP’04

M(DsJ) [GeV]

J=1

J=2

J=1

J=0

DsJ(2317)+ → Ds+0

DsJ(2460)+ → Ds+

Properties studiede.g. helicity in B→DDsJ

Belle,280M BB, M.Danilov,ICHEP’04

Apart from low masses properties in accordancewith lowest level P states JP=0+,1+

Hadron spectroscopy – DsJ mesons


First observation of B0→DsJ(2317)+K-

M(Ds0)-M(Ds) [GeV]

Events in Mbc,E signal region

B0→DsJ(2317)+K-

B0→DsJ(2317)-+

Measured branching fractions Br(B0-> Ds K-)=

(2.93±0.55±0.79)x10-5

Br(B0-> Ds +)=

(1.94±0.47±0.52)x10-5

Br(B0→DsJ(2317)+K-)=(5.3±1.4±0.5±1.4)x10-5

Belle,152M BB,A.Drutskoy,ICHEP’04

Conclusions


Num. of hep-ex

0

50

100

150

200

250

1994 1996 1998 2000 2002 2004

year

Aleph+Delphi BaBar+Belle

2000.5

2001

2001.5

2002

2002.5

2003

2003.5

2004

2004.5

1960 1970 1980 1990 2000 2010

year

year

CPV in Ksystem

new charm states

direct CPV inB system

Ba/lle mature exp., testing SM with high precision 1964: CPV in K system, 2001: CPV in

B system 2004: sin21() is a precision measurement (±6%) 1999: direct CPV in K system, 2004: direct CPV in B

system; CKM predictions confirmed 2() measured many measurements stat. limited, in 2 years ~2x more

data

J/(c quark)

CPV in B system

direct CPV inK system

Continuum suppression backup slide

continuum

Y (4S)

e+e- → qq “continuum” (~3x BB)

e+

e-

e+

e-

qq

Signal B

Other B

Continuum

Jet-like

BB

spherical

To suppress: use event shape variables

CKM Matrix – sin21backup slide

b

q1

q2

q3

Vq3b

V*q2q1

W

b

q2

q2

q1

Vqb

V*qq1q

W

g

Tree QCD penguin

sin21()CP asymmetry:

2

2

00

00

||1

)sin()Im(2)cos()||1(

),(),(

),(),(

CP

CPCP

CP

f

ff

CPCP

CPCPf

mtmt

tfBPtfBP

tfBPtfBPa

f

f

A

A

p

q

CP in decay: |A/A| ≠ 1

CP in mixing: |q/p| ≠ 1

CP in interference between mixing and decay: || = 1, Im() ≠ 1

|| ≠ 1

SM: |q/p|-1~4(mc

2/mt2)sin1~5x10-4

in B system || ≠ 1signals direct CPV


b → ccs: tree + penguin contribution ~ VcbVcs*=A2

penguin only contribution ~ VubVus*=A4(-i)

)10(

)03.0(ln12

2sin)Im(

32*

*

2

2

*

*

*

*

*

*

OrVV

VVr

Om

m

T

PPr

VV

VV

VV

VV

VV

VV

A

A

p

q

penguin

cscb

ubuspenguin

b

tsut

penguin

Ks

cscd

cscd

cbcs

cbcs

tdtb

tdtbKsKs

f

f

(q/p)B A/A

(q/p)K

level of hadronicuncertainty due tointerference(direct CP)


CP sample NTAGpurity ηCP

J/ψ KS (KS→π+π-) 2751 96% -1

J/ψ KS (KS→π0π0) 653 88% -1

ψ(2S) KS (KS→π+π-) 485 87% -1

χc1 KS (KS→π+π-) 194 85% -1

ηc KS (KS→π+π-) 287 74% -1

Total for ηCP=-1 4370 92% -1

J/ψ K*0(K*0→ KSπ0) 572 77% +0.51

J/ψ KL2788 56% +1

Total 7730 78%

BaBar, decay modes used:

sin2β = 0.722 0.040 (stat) 0.023 (sys)

Fit result with ||=1 fixed

when left free:|λ|=0.950 ± 0.031 (stat.) ± 0.013

Miss-tagging probability,resolution function:from self-tagged eventsB→D*l, D, …

)(cos1||

1||sin

1||

Im2)21(1

4)(

2

2

2

/||

tRtmtmwqe

tP l

t

sig

Fitting function:

BaBar:

S A



22 )()2( iCMbc pEM 2CMi EEE

yield signal region

J/ψ KL signalJ/ψ X backgroundNon-J/ψ background

BABAR227M BBM.BruinsmaICHEP’04

274M BBT. HiguchiICHEP’04

B→J/ KsB→J/ KL

Nsig=4370 Nsig=2788

Nsig=4150 Nsig=2722

to isolate B→fCP decays from bckg.


from b→ssspenguin contribution ~ VcbVcs*=A2

another penguin contribution ~ VubVus*=A4(-i)

S~sin21, theor. clean

“sin21”= -0.96 0.51 152M BB,PRL91,261602(2003)

S = 0.06 ± 0.33 ± 0.09274M BB, ICHEP’04 2.2 away from ccs


S = 0.50 ± 0.25 ± 0.06227M BB, ICHEP’04

2.7 away from ccs 2.4 away from ccs

conservativeupper bound:|SKs-S’KS|<0.2

Grossman et al.

’Ks average: 0.41±0.11Ks average: 0.34±0.21

S’KS or SKS at present value would be sign of NP

CKM Matrix – 2backup slide

u,c,t

M+-= -Te-i2 + PeiP

M+0= 1/√2(TceiC + T)e-i2

M00= 1/√2(TceiC e-i2 + PeiP)

S = √(1-A2)sin22eff

A ~ sinP

b

d

W+ ud

d

uB0

T ~ Vub*Vud ~ 3

+

-

S=sin22

A=0

b

dd

uu

d

b

d

W+

u

ud

d

P ~ Vtb*Vtd ~ 3

B0+

-B0

0

0W+

Tc ~ Vub*Vud

Ispospin relations for B→

2 fromB→BaBar


B→ from BaBar

could be mixed CP state, but observed to be almost pure CP=+1

122M BB, Moriond QCD’04Slong=-0.19±0.33±0.11Along= 0.23±0.24±0.14

89M BB, PRL91(2003),171802Br(B+→)=(22.5±5.6±5.8)x10-6

227M BB,M.A.Giorgi,ICHEP’04Br(B0→) < 1.1x10-6 @90% CL

2 fromB→BaBarB→( from Ba/lle

not CP eigenstate, 4 amplitudes considered:


Decay time distribution:

indirect CPV parameter (2)

direct CPVparameter

(B0→)+ (B0→)

(B0→)+ (B0→)

strong phase diff. between amplitudes

asymmetry between

direct CPV asymmteries

Belle: selected bands

BaBar: assume 3 dominated by +,-,0 and fit Dalitz plot



CKM Matrix – direct CPV backup slide

B→K±0

ACP= 0.04 ± 0.05 ± 0.02

274M BB,Y.Sakai,ICHEP’04

)()(

)()(

fBfB

fBfBCP

A

c.f. in B→K+-

ACP= -0.101±0.025±0.0052.4 diff._

d

K

u u

B b

d

ACP= 0.06 ± 0.06 ± 0.01BaBar,M.Chrintinziani,ICHEP’04

B-→K-0 B+→K+0

Large EW penguin?

CKM Matrix – direct CPV backup slide

u,c,t

b

d

W-

uu

s

d

K-

+B0

P ~ Vtb*Vts ~ A2

b

d

W- us

d

uB0

T ~ Vub*Vus ~ A4

K-

+

Contributions to B0→K-+


b

u

W- us

d

cB-

T ~ Vcb*Vus ~ A3

K-

D0

b

uu

u

cs

B-

K-W-

Tc ~ Vub*Vcs ~ A3 (+i) ~ ei3

D0

Basic idea: use B-→K-D0 and B-→K-D0 with D0,D0→f interference ↔ 3

Gronau,London,Wyler, 1991: B- → K-D0CP

Atwood,Dunietz,Soni, 2001: B- → K-D0(*)[K+-]Belle;Giri,Zupan et al., 2003: B- → K-D0(*)[Ks+-] Dalitz plot

or any other common3-body decay;Dalitz density dependson 3

3.01.0)*(

)*(0)(

0)(

KDBBr

KDBBrrB

Sensitivity depends on


Belle: Use continuum D0 from D*– D0π–, D0 Ksπ+π–

decay to model Dalitz plot density.

E Mbc

B± D0 K±

D0 Ksπ+π–

B± D0 ± miss-id

B+ D0K+

M2(Ks+)

M2(Ks-) B- D0K-

M2(Ks+)

M2(Ks-)

Belle,152M BBA.Bozek,ICHEP’04

Visible asymmetry

Fit with 3,,rB free

26o < 3 < 126o @ 95% C.L.

rB = 0.26 ± 0.110.15 ± 0.03 ± 0.04


BaBar,211M BBG.Cavoto,ICHEP’04

3

rB

68%

90%

3

rB97% 74% 20%

Belle,152M BBA.Bozek,ICHEP’04

CKM Matrix – |Vub|backup slide

large non-perturbative corr.(large th. uncertainty)

q2

Mx2

used in measurement

(q2cut,MXcut) 8 GeV2, 1.7 GeV

Vub 6%-9%

only q2cut 11.6 GeV2

Vub 12%-15%

C.W.Bauer et al.,hep-ph/0111387

|Vub|= (4.92 ± 0.39 ± 0.36 ± 0.46)x10-3

|Vub|= (4.77 ± 0.28 ± 0.28 ± 0.690.39)x10-3

MX only

Mx-q2

Babar-CONF-04/11,ICHEP’04

CKM Matrix – |Vub|backup slide

|Vub|= (4.92 ± 0.39 ± 0.36 ± 0.46)x10-3

Mx-q2

|Vub|= (5.54 ± 0.42 ± 0.50 ± 0.55)x10-3

(stat.) (syst.) (th.)

BaBar syst.: largest from detector (tracking, ID) and b→cl modelingBelle syst.: MC statistics

BaBar

Belle

X(3872) backup slide35±7 eventsM=3872.0±0.8 MeV<2.3MeV (90%)

M(J/ +-)

6)/(/)(

7)/(/)(

6.0)/(/)/(

40.0)/(/)/(

1.1)/(/)(

89.0)/(/)(

000

2

1

JXDDX

JXDDX

JXJX

JXJX

JXX

JXX

c

c

BaBar

X(3872)backup slide

c”

hc’

c1’

2

c2

3

M too low and too small

angular dist’n rules out 1

J/ way too small

c too small; (PRL 93, 2003)

c should dominateJ/

c& DD) too small

- Isospin violating decays to J/ +-

C(J/)=-1,C()=-1 → C(X)=+1

Since is not C eigenstate, decay X→J/is probably X→J/(as indicated by m())

I()=1, I()=0, I(J/)=0 → X decays break isospin symmetry

ccuu=1/√2 cc [1/√2 (uu+dd)+1/√2 (uu-dd)]=1/√2(|I=0>+|I=1>)

DsJbackup slide

Belle, 87fb-1,PRL92,012002(2004)

M(Ds0)-M(Ds) M(Ds*0)-M(Ds*)

helicity angle:

Feynman diagrams for B0→DsJ+K-

Documents

B . Golob, University of Ljubljana 4 Seas Conference 2004, Istanbul