2007/3/18 Moriond QCD 2007

B →K, and KK Ratios of Branching Fractions Observation of B+ →K+K0 and B0 →K0K0

ACP of K+-, K+0 and +0

B+ →ρ+K0

B0→ρ0ρ0

B0→ K*B0→a0

-π+ and a0-K+

Conclusion

Sheng-Wen Lin

National Taiwan University

Hadronic B Decays at BELLE and BABAR

2007/3/18 Moriond QCD 2007

Puzzle of KBuras, Fleischer et al, APO B36(2005)2015-2050

Within the SM:

Rc-Rn≈0, Acp(K+π-) - Acp(K+π0)≈0

New Physics :

B0→π0K0 and B+→π0K+ may have color-allowed EW penguins form

Rc and Rn have sizeable effects by EW penguin

Described theoretically by q and q : strength of the EW penguin with respect to the tree contribution

: CP-violation phase

04.005.0

028.0021.0

11.1

05.014.1

943.0

Rn

Rc

R

2007/3/18 Moriond QCD 2007

Theory of KK B+ →K0K+ and B0→K0K0 are dominated by b →d penguin B0 → K+ K- is from annihilation diagram J.-M. Gerard and W.-S. Hou, PLB 253, 478 (1991) BF of B+ →K0K+ and B0→K0K0 are of order 10-6

Sizable asymmetry of O(45%) of B0→K0K0

C.-H. Chen and H.-n. Li, PRD 63, 014003(2001) There is no CP asymmetry in the B0→K0K0 mode and small BF f

or B0 → K+ K- is expected if no strong FSI effect

2007/3/18 Moriond QCD 2007

K+ - and + -

B→K+- B→+-

Sig(red)

Con(dash)

rareB(hatched) + -→K+-

(dotted)

hep-ex/0609015 449M BB

227M BBPRD 75, 012008 (2007)

Consider the final state radiation effects in these modes

sPlots

2007/3/18 Moriond QCD 2007

BF of K+π0,π+π0 and K0π0

0 K0 K00

hep-ex/0609015

Simultaneous fit for π+π0 and K+π0 at Belle and BaBarUse MES and Mmiss to extract yield for K0π0 at BaBar

449M BB

hep-ex/0607106

hep-ex/0607096

347M BB0 K0 K00

2007/3/18 Moriond QCD 2007

B→KK: Observation of b → d penguin

PRL 97, 171805(2006)hep-ex/0608049(submit to PRL)

449M BB347M BB

K+K-

K0K+

K0π+

K0K0

5.3σ

6.0σ

5.3σ

7.3σ

2007/3/18 Moriond QCD 2007

Summary of B →hh

2007/3/18 Moriond QCD 2007

2007/3/18 Moriond QCD 2007

New Electroweak Penguins in the Ratios Rn and Rc

SM

Old WA Data

Belle

q: measures the importance of the EW penguins with respect to the tree-diagram-like topologies: CP-violating weak phase

Buras, Fleischer et al, APO B36(2005)2015-2050

BaBar

2007/3/18 Moriond QCD 2007

Direct CP Asymmetries(Belle) K+π-: -0.093±0.018±0.008

(4.7σ)

K+π0: 0.07±0.03±0.01

(2.3σ)

π+π0: 0.07±0.06±0.01

Acp(K+π-) - Acp(K+π0)

4.4σ

The other decay modes:

hep-ex/0608049(submit to PRL)

Preliminary

2007/3/18 Moriond QCD 2007

K+π-: -0.108±0.024±0.007(4.3σ) (2542±67)

K+π0: 0.016±0.041±0.010

π+π0: -0.019±0.088±0.014

Acp(K+π-) - Acp(K+π0) 2.6σ

Direct CP Asymmetries(BaBar)

hep-ex/0607106

347M BB

Observation of K+π- Direct CP asymmetry: -0.107±0.018+0.007

-0.004 (5.5σ) (4372±82) Using dE/dx as a discriminating variable in the M.L. fit |cosθSpher|<0.9→ |cosθSpher|<0.8

Total increase in rec. eff. is 52%

383M BBhep-ex/0703016(submit to PRL)

2007/3/18 Moriond QCD 2007

BF of B+→ρ+K0 and search for B+→ K*0K+

ρ+K0

Pure penguin b→s PV decayBranching Fraction : (8.0 +1.4 -1.3 ±0.5)x10-6 (7.9σ)CP asymmetry: (-12.2±16.6±2.0) %Observation of this modeBF and ACP are consistent with SM

hep-ex/0702043 383M BB

.). %90( 102.2))1430((Br

)6.1( 10) )1.1( 2.03.06.0()(Br

60*0

60*

LCKKB

KKB

Dominated by the bdg penguin amplitude

bd analogue of B+ρ+K0 (both VP and penguin)ρ+K0

Mπ+π0cosθρ

2007/3/18 Moriond QCD 2007

Evidence for B0→ρ0ρ0

tree contribution is color-suppressed→decay rate is sensitive to the penguin amplitudeComplete the isospin triangleBranching Fraction: B0→ρ0ρ0:1.07±0.33±0.19 x10-6 (3.5σ )Upper limit: B0→ρ0f0(980),f0→π+π -: < 0.53 x 10-6

B0→f0(980)f0(980),f0→π+π -: < 0.16 x 10 -6

longitudinal polarization fraction : 0.87 ±0.13± 0.04

hep-ex/0612020

383M BB

2007/3/18 Moriond QCD 2007

B0 K*0

013.0045.0))1430((

013.0038.0227.0))892((

036.0853.0))1430((

015.0040.0506.0))892((

049.0040.0

0*2

0

0*0

061.0069.0

0*2

0

0*0

KBf

KBf

KBf

KBf

L

L

03.015.017.0))((

04.014.012.0))1430((

03.007.003.0))892((

0*0

0

0*2

0

0*0

KB

KB

KB

CP

CP

CP

A

A

A

)8.9( 10)3.08.00.5())((Br

10)6.07.06.4())1430((Br

)7.9( 10)6.01.18.7())1430((Br

)0.21( 10)6.07.02.9())892((Br

60*0

0

60*0

0

60*2

0

60*0

KB

KB

KB

KB

K*(892)

K*(1430)

H1H2

Full amplitude analysis:

384 M BB

PRL 98: 051801, 2007

2007/3/18 Moriond QCD 2007

Search for B0→a0-π+and a0

-K+

)1.3(3.05.18.0)1450(

)3.2(8.02.25.3)1450(

)9.1(2.06.00.1

)1.3(3.08.01.2

)10)((Br)(Br

0

0

0

0

600

0

Ka

a

Ka

a

aXaB

Evidence taht a0(980) meson is a four-quark state

a0-π+

a0-K+

a0(1450)-π+

a0(1450)-K+

Preliminary

2007/3/18 Moriond QCD 2007

Conclusion Kπpuzzle Two ratios: Rn, Rc Belle : consistent with SM prediction BaBar : also move towards SM prediction Significant difference between Acp(K+π-) and Acp(K+π0) Large colour-suppressed trees Observation of b →d modes and B+→ρ+K0

Only from BaBar Evidence of B0→ρ0ρ0 at BaBar fL~0.5 in BK*, implies |A0| |A+1| >> |A-1| a0(980) meson like a four-quark state

2007/3/18 Moriond QCD 2007

Backup

2007/3/18 Moriond QCD 2007

Beam constrained mass :Precise beam energy known from acceleratorLower error on momentum resolution

Energy difference :Asymmetry shape and shift due to energy lossEbeam : run dependent beam energyEB* and PB* are the reconstructed energy and momentum of the B candidates in CM frame

B signal reconstructionThe signal yield are usually extracted by Mbc and ΔE

2007/3/18 Moriond QCD 2007

PHOTOS

Final state radiation (FSR) effects:

PHOTOS included in our MC

for all B→hh modes.

Systematic uncertainty of PHOTOS

in B→hh now calculated ~ 1/million

(negligible for non-SUPERB statistics):

E. Barberio, Z. Was Comput. Phys. Commun. 79,291 (1994)

B0

PHOTOS v 2.13PHOTOS v 2.13•Interference on, Interference on, •double photon on, double photon on, • Ecut~26MeVEcut~26MeV

G.Nanava and Z.Was G.Nanava and Z.Was hep-ph/0607019hep-ph/0607019

h

9.4% 5.8% 3.6%

Impact on eff w/o PHOTOS

2007/3/18 Moriond QCD 2007

Calibration of signal PDF

Signal PDF

Signal MC sample

The PDF of data and MC are the same ?

Control sampleLike B- →D0-

Data

MC

2007/3/18 Moriond QCD 2007

Correction of efficiency

PID selection

0 reconstruction efficiency

Track reconstruction efficiency

KS reconstruction efficiency

D*+ →D0+, D0 →K-+

D0→K-+ and D0→K-+0

D*+→D0+,D0→+-KS

D+→K-++, D+→KS+

2007/3/18 Moriond QCD 2007

2D Ext. Un-binned ML Fit

2007/3/18 Moriond QCD 2007

Systematics of Br(Bhh)

Systematics of FSR is about 1.0%

2007/3/18 Moriond QCD 2007

Systematics of Acp

detector bias of Kπ0,ππ0 from qq bkg in (ΔE, mbc)

detector bias of Kπ from D*+ 　 D0(Kπ)π+

2007/3/18 Moriond QCD 2007

B0 → 00

Too earlyOn time9000<t<11000Too late

~5.28GeV/c2

Bhabha events

Time information

Off-time events

Difficult to model the distribution for off-time QED background with MC

Re-process the raw-data for timing information

2007/3/18 Moriond QCD 2007

BF. of B0 →00

277M BB

535M BB

hep-ex/0610065