1. Electroweak and Radiative Penguin Transitions from B Factories Paoti Chang National Taiwan University 2 nd KIAS-NCTS Joint Workshop on Particle Physics, String Theory and Cosmology 26-28 December, Taipei 2014/12/26Paoti Chang 1EW and radiative penguin transitions

2. Introduction Electroweak and radiative B decays are sensitive to new physics in the penguin loop.  Small SM branching fraction ( B )  More precise theoretical predictions  Many observables: B, A cp, A FB, P 5 ’, iso-spin asym. … In this talk :  2014/12/262EW and radiative penguin transitions H   1. B (B  X s  ) ; 2. A cp (B  X s(+d)  B  X s l  l  : A FB, B, A CP

3. B  X s , Measurements & Prediction 2014/12/26EW and radiative penguin transitions3  NNLO calculation: B (B  X s  ) = (3.15  0.23)x10  with E  > 1.6 GeV. Misiak et al., PRL 98, 022002 (2007)  Experimental measurements  Require minimum E   Inclusive approach 1. Subtraction with off- resonance data 2. Lepton tags or full reconstruct the other B  Semi-Inclusive approach Reconstruct many X s states. *

4. The Dual of B Factories 2014/12/26EW and radiative penguin transitions4 Mt. Tsukuba

5. Successful Operation 2014/12/26EW and radiative penguin transitions5

6. B  X s  semi-inclusive Data sample: 711 fb  (772 BB pairs) Signal reconstruction: 1. 1.8 <E  <3.4 GeV; veto   and  2. X s = 1K  (K S ) + up to 4    Signal Model: 2014/12/26EW and radiative penguin transitions6 1K  (K S ) +  + up to 2  * 3K with at most 1K S  + up to 1  0.6 < M Xs < 2.8 GeV/c 2  38 states Generate with { arXiv:1411.7198 submitted to PRD 38 X s states correspond to 70% of total.

7. B  X s , Analysis Veto D decays, B  D (*) (K  )  Continuum suppression is achieved by combining shape variables, tagging and  E = E B - E beam into Neural Network after the  E cut. Choose the best candidate based on NN value. Fit on M bc in 19 M Xs bins. 2014/12/26EW and radiative penguin transitions7 * * 2 2 Signal qq Non-peaking BB Cross-feed Peaking BB 0.8 < M Xs < 0.91.9< M Xs < 2.0

8. B  X s , Preliminary results 2014/12/26EW and radiative penguin transitions8  With 0.6 1.8 GeV) B (B  X s  ) = (3.51  0.17  0.33) x 10  *  Calibrate the Xs fragmentation model by comparing the 10 categor. of final states in data and MC.

9. B (B  X s  ), comparison 2014/12/26EW and radiative penguin transitions9 Extrapolation to E  > 1.6 GeV and compare with theory B (B  X s  ) = (3.74  0.18  0.35) x 10  * Best semi-inclusive result

10. Direct CP Asymmetry in B  X s/d  Small A CP in SM. A CP = 2014/12/26EW and radiative penguin transitions10 A CP (SM) B  X s  B  X d   0.6%  2.8%  62%  14% B  X s+d   0 Benzke et al., PRL 106, 141801 (2011)  (B  f)  (B  f)  (B  f)  (B  f) Belle 152 M BB Babar 383M BB Babar 383M BB CLEO 10M BB  q (f = X s,d  )  avg q q, q = d, s q  Im (V uq V ub V cq V cb ) * * Due to unitarity of CKM matrix,  =   ds Hurth et al., Nucl. Phys. 704, 56-74 (2005)  Clean Probe for new physics  Previous results

11. A CP (B  X s , Semi-inclusive Data sample: 429 fb   471 x 10 6 BB pairs Flavour specific X s states: 10 for B  and 6 for B 0 Require 1.6< E  < 3.0 GeV Best candidate:  E/  E, M Xs, FWM, thrust, P Reject continuum : shape variables &  0 score Possible asymmetry bias: 2014/12/26EW and radiative penguin transitions11  *  Asymmetry due to  (K  )  D*   D 0    D 0      Peaking BB background  MC PRD 90, 092001 (2014)

12. A CP (B  X s  and  A CP With BaBar full data sample,  A(X s  ) is related to C 8g and C 7 , 2014/12/26EW and radiative penguin transitions12 A CP (B  X s   Most precise  A(X s  A CP (X s  ) – A CP (X s  ) =   0  78 88 mbmb   A(X s  ) = 4   s Im(C 8g /C 7  ) ≈ 0.12 Im(C 8g /C 7  ) 100 MeV Interference amplitude:  78 ; 17<  78 < 190 MeV In SM, C 8g and C 7  are real.   A = 0 Benzke et al., PRL 106, 141801 (2011)

13. Implication on Im(C 8g /C 7   2014/12/26EW and radiative penguin transitions13 Minimum  2 = 22 min [ (  A Th –  A Exp ) 2 ]  78  1.64 < Im(C 8g /C 7  ) < 6.52 @90% CL Im (C 8g /C 7  ) min    78 (MeV)

14. B  X s+d , Analysis method 2014/12/26EW and radiative penguin transitions14  1.7 < E  < 2.8 GeV  Veto  from  0 (  )    Veto pile-up  based on timing info.  Tag leptons with 1.10 < P < 2.25 GeV/c  Suppress the continuum using BDT. * *  Topological variables: Thrust, Modified FWM  Kinematic variables: M miss, E T 2  Isolation and calorimeter variables for  BDT

15. B  X s+d , Background Calibration Sources: 2014/12/26EW and radiative penguin transitions15  Continuum  off-resonance   and  to  Estimated from MC with correction factors in P  (  ). Study   and  veto using BDT sideband.  Other BB background from MC. 0 C = N ON  off  N off N MC  Measure B (B  X    in data and MC

16. B  X s+d , Wrong Tag Fraction W = W osc + W sec + W misID A CP = A CP Detector bias 2014/12/26 EW and radiative penguin transitions 16 truemeas 1 – 2W 1  B-B mixing  d = 0.187  W sec from MC.  D*   D 0 (K    )   for misID  Lepton ID e - passe  fail ; A LID = = (0.11  0.07)% Tag-and-probe using J/      = N pass N pass + N fail          Asymmetry in BB background * Data in E  < 1.7 GeV  (  0.14  0.78)%  Tracking Partially recon. D*  (  0.01  0.21)%

17. A CP (B  X s+d  ), Preliminary 2014/12/26EW and radiative penguin transitions17  770 M BB pairs A CP = N   N  N   N  Background subtracted A CP in E  threshold true obs

18. Comparison with other results 2014/12/26EW and radiative penguin transitions18  Most precise measurement. Statistical uncertainty dominant A CP (B  X s+d  ) = (2.23  4.02  0.78)% E  > 2.1 GeV * E  > 2.2 GeV * {

19. B  Xs   The Xs   decay can be expressed with C 7, C 9 & C 10. Probe new physics with observables as a function of q   M   BF, A CP   A FB, A iso, f L … other variables A FB = 2014/12/26EW and radiative penguin transitions19 N(cos  >0) – N(cos  <0) N(cos  >0) + N(cos  <0)  Re [ (2C 7 + C 9 ) C 10 ] eff MbMb 2 q 2 A FB in B  K*   has been measured by many experiments. Less theoretical uncertainty in inclusive B  Xs   

20. B  X s  , semi-inclusive 18 states for X s, 1 K  (K S ) + up to 4  (at most 1   ). Only 10 flavor specific states are used for A FB. (M Xs < 2.0 GeV/c 2 ) Veto J/  (  ’)     wider veto range for e  e   Suppress background using Neural Bayes (23 variables). Peaking backgrounds  2014/12/26EW and radiative penguin transitions20  Semi-leptonic B decays  Lepton vertex separation  Missing mass  Visible energy  Continuum  Shape variables 1. Leakage from B  J/  (  ’) X s veto. 2. Double miss ID from B  D ( * ) n   Swapped mis ID in B  J/  (  ’) X s  Estimated using MC  Estimated using data  Included in the fit arXiv:1402.7134 submitted to PRL

21. B  X s  , Signal Extraction Divide data into 4 q 2 regions to perform a fit. Correct A FB to A FB. 2014/12/26EW and radiative penguin transitions21 raw true Rec. Eff. A FB =    x A FB =  ee x  x A FB true raw,  raw, ee  : scale factor due to rec. efficiency  : correction due to different J/  (  ’) veto range. Derive  using MC with various sets of C 7, C 9, C 10

22. A FB (B  X s   , Results 2014/12/26EW and radiative penguin transitions22 A FB The measured A FB values are consistent with the SM.  The deviation of the 1 st bin is 1.8 .  Exclude A FB 10.2 GeV 2 /c 2 at 2.3 .

23. B  X s  , semi-inclusive Reconstruct 10 X s states with 1K (K S ) + 0  2    for branching fraction and  7 self tagged states for A CP.  This 10 X s states correspond to 70% of inclusive rate  with M Xs < 1.8 GeV/c 2. Estimate the missing states and the states with M Xs > 1.8 GeV/c 2 using JETSET fragmentation and theory predictions. Kinematic requirements: 2014/12/26EW and radiative penguin transitions23 0 M ES > 5.225 GeV/c 2 ;  0.1<  E < 0.05 GeV for X s ee ;  E| < 0.05 GeV for X s 

24. B  X s  , Analysis Strategy Use likelihood ratio defined from BDT output to distinguish signals and backgrounds. Veto J/  and  ’. Measure d B (B  X s   )/dq 2 in 6 q 2 & 4 M Xs bins. Measure A CP (B  X s   ) in 5 q 2 bins. 2014/12/26EW and radiative penguin transitions24 Likelihood ratio on J/  sample  Data sample: 471x10 6 BB pairs

25. B  X s  , Signal Extraction Extract signals from 2D ML fit on M ES and LR 2014/12/26EW and radiative penguin transitions25 5 th q bin for X s ee 1 st q bin for X s 

26. B (B  X s   ), Results 2014/12/26EW and radiative penguin transitions26 X s ee X s  X s ll SM Phys.Rev.Lett. 112, 211802 (2014)  1<q 2 < 6 GeV/c 2 Consistent with the SM SM   q 2 >14.2 GeV/c 2 SM  Consistent with the SM at  1 

27. A CP (B  X s   ), Results 2014/12/26EW and radiative penguin transitions27  Over the full q 2 range, A CP (B  X s   ) = 0.04  0.11  0.01 Phys.Rev.Lett. 112, 211802 (2014) Consistent with 0, as expected with the SM.  A CP in each q 2 is also consistent with 0

28. Summary Several B  X s  ( ) measurements are reported.  Most precise semi-inclusive B (B  X s  ) from Belle  Most precise A CP (B  X s  ) from BaBar  First  A CP (B  X s  ) and constraint on Im(C 8g /C 7  )  Most precise A CP (B  X s+d  ) from Belle  First A FB (B  X s   ) from Belle  First B (B  X s   ) and A CP (B  X s   ) from BaBar Expect precision measurements in Belle II. Full hadronic tag for inclusive analysis. 2014/12/26EW and radiative penguin transitions28

29. BACK UP 2014/12/26EW and radiative penguin transitions29

30. B  X s    semi-inclusive 2014/12/26EW and radiative penguin transitions30

31. B  X s   , Results 2014/12/26EW and radiative penguin transitions31 N  = 160.8  20.0 N ee = 139.9  18.6 forward backward XseeXsee XsXs Signal + cross feed Combinatorial Peaking background HIST The dominant systematic errors are  &  and peaking bkg.

32. B  X s  , semi-inclusive 2014/12/26EW and radiative penguin transitions32