1. Improved measurements of B → hh decays at Belle
Sheng-Wen Lin
National Taiwan University, Department of Physics
Motivation
BF of B →K and 
Observation of B+ →K+K0 and B0 →K0K0
ACP of K+-, K+0 and +0
B0 →00
Conclusion
2006/11/01

2. Motivation I Exciting results on ACP in B0 →K+ - and B+→h+0
Large BF of B0 →00
Theoretical predictions for direct CP violation and BFs of B →hh
Evidence of B+ →K+K0 and B0→K0K0
Last publication : BF of B → hh (78 fb-1)
449 M BB
It is time to update the BFs of B→hh modes
2006/11/01

3. Theory of K and  PQCD : H.-N. Li and S. Mishima, hep-ph/0602214
NLO : vertex correction, quark loop and magnetic penguin
FSI : H.-Y. Cheng, C.-K Chua and K.-C. Yang, PRD 71, (2005)
SD(LD) : short(long) distance correction
2006/11/01

4. Theory of K and  These three ratios depend weakly on the inputs
PQCD : H.-N. Li and S. Mishima, hep-ph/
These three ratios depend weakly on the inputs
Buras, Fleischer et al, APO B36(2005) R=
Rn, Rc affected by EW penguins
Rc=1.14 0.05
Rn=
New Physics?
2006/11/01

5. 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
2006/11/01

6. Theory of KK Extract the angle 3 from the B →KK branching fractions
B+ →K0K+ increases with 3 while BF(B0 → K+ K- ) decreases with 3
There is no CP asymmetry in the B0→K0K0 mode and small BF for
B0 → K+ K- is expected
if not, exist strong FSI effect
C.-H. Chen and H.-n. Li, PRD 63, (2001)
K0K+
K0K0
K+K-
2006/11/01

7. PHOTOS g Final state radiation (FSR) effects:
E. Barberio, Z. Was
Comput. Phys. Commun. 79,291 (1994) p- p+ g B0
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):
PHOTOS v 2.13
Interference on,
double photon on,
Ecut~26MeV
Impact on eff w/o PHOTOS
p+p-
K+p-
h+p0
9.4%
5.8%
3.6%
G.Nanava and Z.Was hep-ph/
2006/11/01

8. Feeddown Simultaneous Fit K+- K+- sample other +- other +-ample
+- fake
K+- sample
other
+-
K+- fake
other
+-ample
Decays with simultaneous fit : K+0+0, K+K0+K0
2006/11/01

9. K+ - and + - hep-ex/0609015 Sig : 2D Smooth histogram
Apply ΔE and Mbc calibration corrections
Con : Argus(Mbc) X 1st order chebyshev polynomial(ΔE)
rareB :2D smooth histogram
Feed-across : 2D smooth histogram
B→+-
B→K+-
Sig
Con
rareB
+ -→K+-
2006/11/01

10. h0,K0 0 and 00
0
K0
K00
00 ?
2006/11/01

11. B0 → 00
Time information
On time
9000<t<11000
Too late
Too early
Difficult to model the distribution for off-time QED background with MC
Re-process the raw-data for timing information
Off-time events
~5.28GeV/c2
Bhabha events
2006/11/01

12. Observation of K0K+ and K0K0
hep-ex/
KS+
KSK+
5.7 
KSKS
K+K-
6.0 
2006/11/01

13. Direct observation of hadronicb→d penguin
Summary of B →hh (I)
Direct observation of hadronicb→d penguin
2006/11/01

14. New Electroweak Penguins in the Ratios Rn and Rc
q: measures the importance of the EW penguins with respect to the
tree-diagram-like topologies
: CP-violating weak phase
New Belle Data w/414 fb-1 SM
Old WA Data
Buras, Fleischer et al, APO B36(2005)
2006/11/01

15. Summary of B →hh (II) The ratios of the B → K branching fractions
0.850.06
1.000.08
0.820.08
PQCD : H.-N. Li and S. Mishima, hep-ph/
2006/11/01

16. Analysis with 535 M BB ACP of B0 →K+- and B+ →h+0
BF. and ACP of B0 →00
2006/11/01

17. Feeddown Single Fit : K+- Simultaneous Fit : K+0+0 K+-
BF(+-)/BF(K+-)
K+-
+- fake
K+- sample
other
Simultaneous Fit : K+0+0
K+0 sample
K+0
other
+0 fake
+0ample
other
K+0 fake
+0
2006/11/01

18. ACP of B0 →K+- PID has charge asymmetry
N( K+- →K-+)
N(K-+)
PID has charge asymmetry
Dilution due to double tracks PID fake
B0→K-+
B0→K+-
B0→K-+
B0→K+-
2006/11/01

19. ACP of B+→h+0
B-→K-0
B+→K+0
B-→-0
B+→+0
2006/11/01

20. Acp (Bhh) Preliminary Significant DCPV in K+π- and π+π-
Black 449 MBB
Blue MBB
Green 535 MBB
Time-dep. analysis
Preliminary
Significant DCPV in K+π- and π+π-
Acp(K+π-) - Acp(K+π0)  4.4σ
2006/11/01

21. B0 →00
hep-ex/ B0
2006/11/01

22. 2006/11/01

23. Conclusion Improved measurement of B→hh BF Rn, Rc with SM prediction
”K puzzle” is no more
Observation of B+→K+K0 and B0→K0K0
Acp(K+π-) - Acp(K+π0)  4.4σ
Maybe colour-suppressed trees
Maybe New Physics
More data is needed to improve the precision of B0→00 result
2006/11/01

24. Backup
2006/11/01

25. B signal reconstruction
The signal yield are usually extracted by Mbc and ΔE
Beam constrained mass :
Precise beam energy known from accelerator
Lower error on momentum resolution
Energy difference :
Asymmetry shape and shift due to energy loss
Ebeam : run dependent beam energy
EB* and PB* are the reconstructed energy and momentum of the B candidates
in CM frame
2006/11/01

26. Calibration of signal PDFMC
Signal MC sample
Data
The PDF of data and MC are the same ?
Control sample
Like B- →D0-
2006/11/01

27. 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+
2006/11/01

28. 2D Ext. Un-binned ML Fit
2006/11/01

29. Systematics of Br(Bhh)
Systematics of FSR is about 1.0%
2006/11/01

30. Systematics of π0π0
Br=1.1±0.3±0.1
2006/11/01

31. Systematics of Acp detector bias of Kπ0,ππ0 from qq bkg in (ΔE, mbc)
detector bias of Kπ　from D*+　　D0(Kπ)π+
2006/11/01

32. BF. of B0 →00
hep-ex/
277M BB
535M BB
2006/11/01