1. New Results from Belle introduction to Belle introduction to Belle CP violations CP violations B   K S ; B  D 0 K + unusual hadron states unusual hadron states D sJ (3872), D sJ (2457) ; X(3872) Youngjoon Kwon Yonsei University Overview

2. 2 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon French n meaning “beautiful” in French n the heroine of a famous musical / Disney animation n an experiment at KEK Belle?

3. 3 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Motivation for Belle CP violation  Simply put, CP violation means matter and antimatter behave differently.  Lorenz-invariant quantum field theory demands invariance under CPT, but nothing more.  In the Standard Model of particle physics, we actually have a mechanism for CP violation: the KM( 小林 - 益川 ) mechanism. Why don’t we go to test it? Understanding the CP violation is a very important subject of particle physics and cosmology  Big bang cosmology suggests a balanced production of matter & antimatter, but our current universe is dominated by matter.  A. Sakharov’s 3 conditions for matter dominance –baryon number non-conservation –C and CP violation –not in thermal equilibrium

4. 4 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon K-M ansatz Makoto Kobayashi Toshihide Maskawa First 3rd- generation particle (  ) seen 1975 CPV is due to an irreducible phase in the quark mixing matrix

5. 5 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Flavor mixing and CKM matrix n For quarks, –weak interaction eigenstates  mass eigenstates –mixing of quark flavors through a unitary matrix Wolfenstein parametrization

6. 6 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon n Interference between 2 amplitudes –indirect: CP eigenstate + mixing –direct: i.e., between tree and penguin diagrams CP violation in the Standard Model n From mixing W t g s W V ub V td f cp B0B0 B0B0 = B0B0 B0B0 n From decay amplitudes

8. 8 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon The Unitarity Trianlge * other triangles are difficult to measure Hoecker et al., CKM-fitter (2003)

9. 9 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Physics Goals of Belle  Establish CP violation in B meson decays and over-constrain the SM picture of CP violation –any inconsistency?  Measure fundamental parameters of SM –10 ( out of 18, not counting neutrino masses, yet ) parameters are related with quark flavors –Belle, in particular, measures CKM triangle parameters; angles & sides  Search for rare/forbidden decays and explore new physics effects

10. 10 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Experimental tools  KEKB accelerator/collider  Belle detector  and the Belle collaboration ~300 members from ~50 institutions

11. 11 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon KEKB Collider Asymmetric e+e- collider to improve vertex separation 8 GeV (e-) / 3.5 GeV (e+)

12. 12 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon KEKB Luminosity History

13. 13 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Belle detector Silicon Vertex Detector (SVD) Impact parameter resolution  55  m for p=1GeV/c at normal incidence Central Drift Chamber (CDC) (  Pt/Pt)2 = (0.0019Pt)2 + (0.0030)2 (Pt in GeV/c)2 K/  separation with dE/dx in CDC (  dE/dx =6.9%) TOF (  TOF = 95ps) Aerogel Cerenkov (ACC) Efficiency = ~90%, Fake rate = ~6% up to 3.5GeV/c , e  with CsI crystals (ECL)  E/E ~ 1.8% @ E=1GeV e  : efficiency > 90% (~0.3% fake for p > 1GeV/c) KL and  with KLM (RPC chambers)  : efficiency > 90% ( 1GeV/c)

14. 14 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon e  e  collision energy for Belle 

15. 15 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Two variables at Y(4S) Energy difference: Beam-constrained mass: 

16. A CP (  t) & CKM angle  1 f cp B0B0 B0B0 = B0B0 B0B0 Note on notations:  1 = ,  2 = ,  3 =  For

17. 17 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Measuring A CP (  t) Reconstruct CP eigenmodes, e.g. B 0  J/  K S Tag the flavor of CP mode by looking at the other B decay Measure  t w.r.t decay point of the other B Calculate A CP (  t)

18. 18 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon CP mode reconstruction in 2911 events are used in the fit. 140 fb -1, 152 x 10 6 BB pairs

19. 19 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon CP mode reconstruction in p B * (cms) J/  K L 1399±67 signal

20. 20 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Flavor tagging  Need to know the B flavor of the CP eigenmode decays  Use inclusive kinematic features of charged particles in B decays –leptons, K, , p  Combine the above info. into 2-level (track- and event-level) multi-dim. likelihood function Efficiency > 99.5%  effective = 28.8  0.5% Flavor-specific decays of B 0 (OF-SF)/(OF+SF) ~ (1-2w)cos(Δm t)

21. 21 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Result q=+1: tag =-1: tag  f : CP eigenvalue d: dilution factor | ccs | = 1.007±0.041(stat) i.e. consistent with no direct CPV

22. 22 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon On the unitarity triangle, sin2  1 (Belle 2003,140 fb - 1 ) =0.733±0.057±0.028 sin2  1 (BaBar 2002, 81 fb -1 ) =0.741±0.067±0.033 sin2  1 (New 2003 World Av.) =0.736±0.049 “beauty contest!”

23. 23 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Note: A f = 0   (B  f ) =  (B  f )  direct CP violation. Af =Af = S f = | f | 2  1 | f | 2  1 | f | 2  1 2Im( f ) f ≡ e  i  M A( B  f ) Standard model predictions ff Indirect CP violation in B 0 B 0 system

24. 24 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon A CP (t) in (q  c) decays

25. 25 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon K  K  K S and  K S events

26. 26 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon S = 0.51 ± 0.26 ± 0.05 +0.18 -0.00 3rd error: due to uncertainty in CP content. (A=-0.01±0.16±0.04) S = 0.43±0.27±0.05 (  K s excluded) poor tags good tags A CP (t) in K  K  K S and  K S Current WA: sin (2φ 1 )=0.736±0.049

27. 27 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon 68±11 In the absence of New Physics, S = sin2  1eff = sin2  1 Theoretically cleanest Belle (78 fb –1 ): S=-0.73±0.64±0.22 How about B   K S ?

28. 28 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon CP Asymmetry in B   K S Poor tags Good tags

29. 29 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon CP Asymmetry in B   K S

30. 30 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon CP Asymmetry in B   K S [Current sin2  1 (world average) = 0.736±0.049 ] (A=-0.15±0.29±0.07) Control Sample S=–0.09±0.26 differs by 3.5 

31. 31 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Systematic Uncertainties CP in the background: (7.2±1.7)% K K K S : (1.6 )% f 0 K S +1.9  1.5 (measured) Correlation between A and S? A =  0.15 ±0.29±0.07 If A is fixed to zero, S =  0.99±0.50 These effects are included in the systematic error

32. 32 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Systematic Uncertainties uncertainties fromSA fitting near |S|=1 +0.06 –0.00 – background K + K – K s, f 0 (980)K s +0.00 –0.08 ±0.04 other background fraction  0.05 ±0.04 vertexing algorithm  0.02  0.05 Total +0.09 –0.11 ±0.07

33. 33 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon CP Asymmetry in B   K S SM sin2  1eff Feldman-Cousins treatment including systematics from CP in the background finds the SM value ruled out at 99.95% CL or 3.5 

34. Extracting  3 from B +  D 0 K + Dalitz analysis

35. 35 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon  3 from B +  D 0 K + Dalitz analysis  Interference if both D 0 and D 0 decay to same final state  total phase  =  +  3  comparing B  and B ,  extract  3 

36. 36 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon D 0  K S     decay structure  78/fb; selected from continuum  D * tag to suppress background  57,800 events  fix the D 0  K S     decay

37. 37 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon B +  D 0 K + events 138 events / 107  12 signals / eff. = 12%

38. 38 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon B +  D 0 K + (D 0  K S     ) Dalitz plots B +  D 0 K + B   D 0 K  70 events 68 events

39. 39 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Fit Results two-fold ambiguity

40. 40 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Fit Results 2.4  significance for CPV with model and systematic uncertainties, 90% confidence level intervals

41. 41 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon  1 and  3 combined  1 from  K S  3 from B  D 0 [K S     ]K V ub /V cb,  m s,  m d,  

42. Unusual Hadron States Unusual Hadron States - mystery “mesons”  D sJ (2317), D sJ (2457)  X(3872)

43. 43 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Observations of D sJ n BaBar (Apr. 2003  PRL) –a new resonance at 2317 MeV in n CLEO (May 2003  PRD) –another resonance at 2459 MeV in

44. 44 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Confirmed by Belle… n D sJ (2317) N = 761 ± 44 events  M = (348.7 ± 0.5) MeV M = (2317.2 ± 0.5) MeV n D sJ (2457) N = 126 ± 25 events  M = (344.1 ± 1.3) MeV M = (2456.5 ± 1.3) MeV

45. 45 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon What’s so strange …? n Surprisingly low mass compared to the potential model expectations –below D (*) K threshold => narrow! n The masses are practically equal to those of similar states in the cu system:  Need to determine the quantum #’s and the BF’s

46. 46 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon D sJ (2457) : new decays ( ) 1st observation  J  0

47. 47 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon D sJ (2457) : new decays ( ) 1st observation  J P  0 +

48. 48 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Other decays disfavors J P = 0 + or 1  consistent w/ J = 0 allows J P = 0 + Consistent with tentative spin-parity assignments: D sJ (2317) => 0+ D sJ (2457) => 1+

49. 49 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon B->D D sJ (2317) D sJ (2317)->D s   B->D D sJ (2457) D sJ (2457)->D* s   B->D D sJ (2457) D sJ (2457)->D s  D sJ production in B decays BF(B->D D sJ (2317)) x BF(D sJ (2317)->D s   ) = (8.5  2.0  2.6)x 10 -4 BF(B->D D sJ (2457)) x BF(D sJ (2457)->D s *   ) = (17.8  4.2  5.3) x 10 -4 BF(B->D D sJ (2457)) x BF(D sJ (2457)->D s  ) = (6.7  1.3  2.0) x 10 -4 PRL, accepted

50. 50 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon D sJ (2457)  D s  decay BF(D sJ (2457)->D s  ) BF(D sJ (2457)->D s *   ) 0.55  0.13  0.08 (continuum) 0.38  0.11  0.04 (B decays) = Consistent with 1 + hypothesis, 0 +, 2 + are excluded from B decays

51. 51 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Summary of new D sJ states  CLEO and Belle confirm BaBar’s observation of D sJ (2317).  D sJ (2457): observed by CLEO (narrow, again!) - mass is below DK threshold: should be broad for 0 + or 1 -  Belle observes both D sJ (2317) and D sJ (2457) in B  D D sJ - consistent with 0 + and 1 + (both having j q =1/2).  D sJ (2457)  D s  - observed by Belle both in continuum and B decays - angular analysis favours the J P =1 + hypothesis of D sJ (2457)  But the masses are unexpected The new D sJ states have nearly the same masses as the D** 0 + and 1 + states.

52. A new narrow state in J/      S  

53. 53 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon a new narrow state in J/     B ±  K ± π + π – J/  in bins of π + π – J/  mass M=3871.8±0.7±0.4 MeV/c 2

54. 54 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Quantity(MeV)M X - M threshold MXMX 3871.8±0.7±0.4 M D 0 +M D *0 3871.5±0.7+0.3±1.1 M D + +M D *- 3879.5±0.7-7.7±1.1 Masses & Width  X < 2.3 MeV (90% CL.) determined by resolution-broadened Breit-Wigner

55. 55 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon X(3872) production/decay M()M()

56. 56 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon A  (1 3 D 2 ) state: –Because D-states have negative parity, spin-2 states cannot decay to DD –They are narrow as long as below the DD* threshold –  (1 1 D 2 ) preferentially decays to  c (1 1 P 1 ). Decays to     J/  would be of magnetic type and are suppressed. –Some models predict large widths for  (1 3 D 2 ) →     J/  –All models predict even larger widths for  (1 3 D 2 ) →  c (1 3 P 2,1 ) D 0 D *0 molecule hep-ph/0308277 Possible interpretations  (1 1 D 2 )  (1 3 D 2 )  (1 3 D 3 )  (1 3 D 1 ) DD  J       7% 65% 14% 32% 20% Based on: E.J.Eichten, K.Lane C.Quigg PRL 89,162002(2002) 5

57. 57 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Can it be 3 D c2 charmonium? Unbinned max. likelihood fitting  (2S) X(3872)

58. 58 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Possible interpretations n The mass of the state is right at the D 0 D *0 threshold! n This suggests a loosely bound D 0 D *0 molecule, right below the dissociation energy “ Molecular Charmonium” discussed in literature since 1975: –Triggered by complicated structure of  (e  e  →hadrons) observed at SPEAR M. Bander, G.L. Shaw, P. Thomas, PRL 36, 695 (1976) M.B. Voloshin, L.B. Okun JETP Lett. 23, (1976), Pisma Zh.Eksp.Teor.Fiz.23, 369 (1976) A.De Rujula, H.Georgi, S.L.Glashow, PRL 38 (1977) –Interactions described by pion-exchange give attractive force for DD*, BB* N.A. Tornqvist, PRL 67, 556 (1991), Z.Phys. C61, 525(1994) A.V. Manohar, M.B. Wise,Nucl.Phys. B339, 17(1993) Q q Q q D 0 D *0 molecule Diquark Model (Qq) are colored Loose binding A different idea from that time: e.g. C.Rosenzweig PRL 36,697 (76) Decays to (QQ)+(light mesons) via quark rearrangement which suppresses the width. QQ q Stronger binding q

59. 59 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Summary !? and then, a new narrow state in J/     with Physics in the B-factories is getting really interesting!! a series of new results on D sJ

60. Back-up Slides

61. 61 KIAS-APCTP Astro-Hadron Symposium Nov. 14, 2003 Youngjoon Kwon Backgrounds