1. Polarization fraction & time-dependent CP analysis of measured at Belle. March 2008 – Geneva Swiss Physical Society – Annual meeting Kim Vervink

2. Motivation b  ccd transition = CP eigenvalue

3. Motivation : clean because “P/T” is estimated small in the SM. : clean because 1 CKM amplitude is dominant. The decay amplitude is CKM suppressed. Any New Physics in the penguins will right away show up, but overall branching fraction is small. Similarity with the “golden” channel: First observation of mixing induced CP violation! very clean measurement of sin2  No hadronic contamination No contamination from other phases Difference:

4. Angular analysis

5. History Branching fraction CP odd fraction and CP violation

6. Luminosity Belle + BaBar > 1 ab - 1 Belle (10 Mar 08) All: ~ 778 fb -1, Cont: ~ 68 fb -1, Y(5S): ~24 fb -1

7. Results All preliminary…

8. Extracting signal Signal events: Show signal in:

9. Angular analysis Comparison with Babar:

10. 2 B-mesons are produced in a boosted frame   t is measured from vertex positions B-mesons are entangled: flavor of B 1 at time t 2 is determined by B 2 decay Decay rates at Belle Standard method (similar method used for )

11. lifetime measurement B-meson lifetime. : background contribution.

12. CP violation measurement Comparison with Babar: Standard Model prediction in absence of penguin diagrams: Compatible with SM prediction. Significance of CPV : 3.8

13. Summary The Standard Model predicts a clean measurement of. With a sample of 500 signal events we find: –Adfa – … with a significance of 3.8 A result compatible with the Standard Model. Kim Vervink

14. Backup slides