1. Page 1 B 0   Ks + quasi 2 body modes Koji Hara (Nagoya University) CKM2006 WG4    from charmless B decays

2. Page 2 Analyses Reviewed Belle  K 0 hep-ex/0608039 (Accepted by PRL)  K 0,f 0 K S hep-ex/0609006 BaBar  K S hep-ex/0607101  K S hep-ex/0608051

3. Page 3 B 0   K S Analysis Procedure 1. Event selection Flavor tagging, vertex reconstruction 2. Loose Continuum suppression Based on event shape variables 3. N sig extraction and CP fit Fit  E-M bc -M  -event shape-cos  H and  t Separate fits: Nsig  CP fit (Belle) Nsig and CP simultaneous fit (BaBar)

4. Page 4 B 0   K S Signal Yields 535 M BB pairs N sig 118+-18 Eff. 17% LR>0.85 LR  0.85 347 M BB pairs N sig 142+-17 Eff. 23%

5. Page 5 B 0   K S tCPV result S =+0.11+-0.46+-0.07 A =-0.09+-0.29+-0.06 S =+0.62 +0.25 -0.30 +-0.02 C =- A =-0.43 +0.25 -0.23 +-0.03 Dominant systematic errors: signal  t., BB BG, tag-side interference Dominant systematic errors: BG frac.,  t resol., tag-side interference

6. Page 6 B 0   K 0 (Belle) Selected   K + K - mass region |M KK -M  |  10MeV/c 2 K + K - K 0 non-resonant contribution is estimated from the separate Dalitz analysis to be 2.75+-0.14%. f 0 K 0 contribution is treated as systematic error. BaBar did KKK 0 time-dependent Dalitz analysis.  Di Marco ’ s talk in WG4-14-PM1

7. Page 7 B 0   K S Yields Fit M bc -  E-LR(event shape+cos  H ) LR LR>0.5 LR  0.5 Data sample: 535 M BB pairs Nsig:  (K + K - )Ks, Ks   +  - 246+-18  (K + K - )Ks, Ks   0  0 40+-9  (KsKL)Ks, Ks   +  - 21+-7

8. Page 8 B 0   K L Yields Fit P B cms -LR Data sample: 535 M BB pairs Nsig: 114+-17 LR

9. Page 9 B 0   K 0 tCPV result S = + 0.50  0.21  0.06 A = + 0.07  0.15  0.05 Background subtracted S  Ks = + 0.50  0.23 A  Ks = + 0.11  0.16 S  KL = - 0.46  0.56 A  KL = - 0.15  0.38 Results for Ks KL separate fit Dominant systematic errors: BG frac.  t resolution, tag-side interference

10. Page 10 B 0  f 0 Ks (Belle) Selected f 0   +  - mass region 0.890<M  <1.088 GeV/c 2 Other B 0   K S decay background is estimated from separate fit to M  Distribution

11. Page 11 B 0  f 0 Ks Yields Data sample: 535 M BB pairs Nsig: 377  25 LR LR>0.5 Fit M bc -  E-LR

12. Page 12 B 0  f 0 K S tCPV result - S = +0.18  0.23  0.11 A = -0.15  0.15  0.07 Dominant systematic errors:    Ks BG (interference effect, CPV)

13. Page 13 B 0    K S (BaBar) Selected  0   +  - mass region 0. 4<M  <0.9 GeV/c 2 B decay BGs are estimated from MC

14. Page 14 B 0    K S Yields Fit M ES -  E-NN- cos   -M  -  t Data sample: 227 M BB pairs Nsig 111+-19

15. Page 15 B 0    K S tCPV result S = +0.20  0.52  0.24 C =- A = +0.64  0.41  0.20 Dominant systematic errors: Interference, PDF uncertainties, mis- recon and fit bias

16. Page 16 Summary S =(-  f sin2  1 eff ) values are consistent with sin2  1 from b  ccs. BaBar  Ks tCPV errors are smaller than Belle. –Similar analysis method is used. –Possible reason:  selection, boost factor, statistical fluctuation. Quasi 2 body analyses has large systematic errors from B decay BG components. –Especially in  K S modes –Time-dependent Dalitz analysis will be necessary for improvement.