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2. 2 July 2004 Liliana Teodorescu 2 Introduction  Introduction  Analysis method  B u and B d decays to mesonic final states (results and discussions) (results and discussions)  Conclusion

3. 2 July 2004 Liliana Teodorescu 3 Rare B decays  branching fractions (BF) less than 10 -5  do not involve CKM favoured b->c transitions Theoretical mechanism  CKM suppressed tree b->u transitions (T)  loop (penguin) b->s or b->d transitions (P)  interference between T and P => direct CP violation Direct CP violation observable weak phase diff. strong phase diff. A CP sizeable whenand

4. 2 July 2004 Liliana Teodorescu 4 Physics interest  Standard Model  Precise tests of the theoretical predictions (small amplitude processes)  Potential evidence for CP violation  Constraints on CKM parameters – extraction of UT angles through  New Physics  New particles hidden in the loops  Constraints on theoretical models SMnon-SM Higgs SUSY Covered in this talk Covered in this talk  direct measurements of the time-dependent asymmetries  branching fraction dependence on the UT angles BFs and A CP (time-integrated) (Babar, Belle, Cleo) Observables  BF  time-integrated CP asymmetry  time-dependent CP asymmetry

5. 2 July 2004 Liliana Teodorescu 5 Signal isolation  identification of reconstructed B with 2 almost uncorrelated kinematical var. beam-energy substituted mass (beam constrained mass – M bc ) energy difference Signal: m ES = m B Signal:  E = 0 Background suppression  “continuum” events - non-resonant B decays: sphericContinuum: jet-like  event shape variables: used independently, in a Fisher discriminant or in a Neural Network Signal extraction  1dim. or multidim. fit of  E, m ES (M bc ), shape var., PID var.  cont. bkg. - modeled with a phase-space function with kinematical threshold - studied with events of sidebands in  E, m ES (M bc ) outside the signal region off-resonance data, MC etc.  other B decays – decay angles, helicity angles etc.  exploit production at threshold and small energy released in Babar, Belle, Cleo

6. 2 July 2004 Liliana Teodorescu 6 HFAG – Heavy Flavor Averaging Group http://www.slac.stanford.edu/xorg/hfag In this talk  used HFAG averages  rely on HFAG references  referenced explicitly only new results Presented in this talk

7. 2 July 2004 Liliana Teodorescu 7 Physics interest  provide information used in CKM angles  (  2 ) and  (  3 ) determination  extraction of angles suffers from hadronic uncertainties in the theoretical calculations  BFs give limits of these hadronic uncertainties  A CP used to establish the direct CP violation in SM or indicate New Physics

8. 2 July 2004 Liliana Teodorescu 8 B ->  +  - B ->  0  0  contributions from color-suppressed tree and gluonic penguin amplitudes  theoretical predictions: BF < 1·10 -6  observation of significant signal B ->  +  0 b->u tree dominated  +  - 78fb -1 82fb -1 15fb -1 142fb -1 3.4  BF (10 -6 ) signal 140fb -1 4.2 

9. 2 July 2004 Liliana Teodorescu 9 BF’s ratios  expectations  significant penguin contribution to  +  - mode => penguin pollution  complicates the extraction of  (  2 ) from time-dependent CP asymmetries CP Asymmetries 82fb -1 Preliminary 140fb -1 Direct CP violation in B 0 ->  +  - 140fb -1 (in time-dependent analysis) Cross check time-integrated asymmetry PRL, hep-ex/0401029 Do not observe CP violation (time-dependent analysis ) Obsevation PR D65, 013004, 2002

10. 2 July 2004 Liliana Teodorescu 10 B ->  K +   b->u tree and b->s penguin transitions  penguin amplitude dominates B ->  K 0  +  no b->u transition, only b->s penguin trans.  good case to determine penguin’s contrib. B ->  K 0  0  dominated by color suppressed tree 82fb -1 78fb -1 15fb -1 Significant penguin contribution isospin relations the 3 ratios = 1 BF (10 -6 )

11. 2 July 2004 Liliana Teodorescu 11 CP Asymmetries B ->  K   could be significant due to interference between T and P amplitudes  no evidence of direct CP violation in K  decay modes B ->  KK BFs  give information about the rescattering processes (FSI)  rescattering can modify BF and A CP for   and K  modes  KK more sensitive to rescattering effects  BF limits in agreement with pQCD predictions (PR D63, 014003 (2000))  no evidence of rescattering yet 82fb -1 Preliminary 9.13fb -1 140fb -1 BF (10 -6 )

12. 2 July 2004 Liliana Teodorescu 12 Physics interest  provide information for understanding the relative contribution of tree and penguin amplitudes in B decays  have potential for establishing the direct CP violation

13. 2 July 2004 Liliana Teodorescu 13 CKM suppressed destructive interference and  /  ’ mixing A CP expected (20-40)% for the suppressed modes flavor-singlet (important for  ´K * ) Belle: -0.02  0.07  0.01 Cleo: +0.03  0.12  0.02 PL B254(1991)247 BF (10 -6 ) K 0, K *0 modes - no external tree agreement with NLO QCD NP B651(2003)225 Preliminary

14. 2 July 2004 Liliana Teodorescu 14 color suppressed dominant CKM suppressed  0,  0 modes - no external tree BF (10 -6 ) Expectations:  BF’s: (0.1-1.0) 10 -6 (  ( ’ )  + the highest)  A CP : large for , small for  A CP hep-ph/0307395 Preliminary

15. 2 July 2004 Liliana Teodorescu 15 Physics interest  provide methods for extracting CKM angle  (  2 ) e.g. decay amplitude isospin analysis of  decay amplitudes are extracted from BFs and A CP asymmetries  test the theoretical models with the BF’s ratio (large range of predictions)

16. 2 July 2004 Liliana Teodorescu 16  needed for the isospin analysis for  extraction using the decay modes:  give limits on the contribution of penguin ampl.  BF predictions around or below 10 -6 hep-ex/0405068 140fb -1 N sig =15.1  4.8 Sig. = 3.5  BF=(5.1  1.6  0.9)·10 -6 82fb -1 BF < 2.9·10 -6 Evidence signal cont. bkg. cont.+ B bkg.  BF higher than the theoretical predictions  central value higher than BaBar limit Some contributions to the decay ampl. higher than expected => isospin analysis more complicated

17. 2 July 2004 Liliana Teodorescu 17 BF (10 -6 ) BF’s ratio Theory  R  6 tree level estimates Z. Phys. C34, 103 (1987)  R  2-3 penguin, off-shell B * Excited states, scalar  +  - resonan. PRL 86,216 (2001), PR D66,034019(2002) Babar A cp no evidence of direct CP violation 82fb -1 140 / 78fb -1 9.1fb -1

18. 2 July 2004 Liliana Teodorescu 18  suppressed amplitudes => BF ~ 10 -6 or even less (e.g. BF(B->  )~10 -9 ) Physics interest  test of theoretical models – many different approaches  search for New Physics signature PRD 68, 015004 (2003)  model independent bound on S: time–dependent CP asymmetry parameter calculated with BF’s of If the experimental  S much higher than this bound => New Physics

19. 2 July 2004 Liliana Teodorescu 19 Sign.Babar 82fb -1 Cleo 3.1fb -1 hep-ex/0403046 Submited to PRL B 0 ->  With the new BF values: S charmonium = 0.736  0.049 S  ’K s = 0.27  0.21 HFAG average

20. 2 July 2004 Liliana Teodorescu 20  angular distribution reflects strong and weak interaction dynamics  aditional observables for detecting direct CP violation or NP f L =  L /  - longitudinal polarization fraction Physics interest   modes provides an alternative method for  measurement

21. 2 July 2004 Liliana Teodorescu 21 B->  K * B->  K * - pure b->s P (unambiguous signiture for P) B->  K * B->  K * - dominant b->s P + b->u tree B->  B->  - b->u Tree and CKM suppressed b->d P (potential  measurement) A CP expectations  K * : 1% in SM, <30% with NP contribution  K * : possible large (T–P interf.)  +  0 : isospin-breaking processes (e.g. EW P)=> high CP asym. BF (10 -6 ) A CP 82fb -1 9fb -1 78fb -1 82fb -1

22. 2 July 2004 Liliana Teodorescu 22 Polarization Theory predictions – longitudinal polarization dominates in all modes Measurements - helicity angular distribution analysis - full 3-dim. angular analysis (  K* 0 - Babar, Belle) fLfL As expected Less than expected!! B->  K * NP in b->s penguin transition? (hep-ph/0310229) 82fb -1 78fb -1

23. 2 July 2004 Liliana Teodorescu 23  observation of B->  0  0 BF = (1.9  0.5)  10 -6 (HFAG)  observation of direct CP violation in B->  +  - (Belle)  no other evidence of direct CP violation  time-integrated CP asymmetries (Babar) need more data to establish a conclusion  evidence for B->  0  0, Sig. 3.5  (Belle) BF higher than theoretical predictions  (Babar)  B->  f L  1 expected (Babar and Belle) B->  K * f L <<1 not expected (Babar and Belle) time-integrated B factories are living interesting times. More interesting ones will come!