1. Selected topics from Belle
Something Unique at Belle and New
- EPR entanglement
- Y(3S) run: Dark Matter Search
- B  D*tn
- Crab cavity study / Super-KEKB
Y.Sakai KEK
SLAC seminar 29-May-2007

2. KEKB / Belle 8 GeV e- x 3.5 GeV e+ KEKB Belle Lpeak = 1.71x1034
~1 km in diameter
Mt. Tsukuba
KEKB
Belle
e+ source
Ares RF
cavity
Belle detector
8 GeV e- x 3.5 GeV e+
Lpeak = 1.71x1034
Integ. Lum. ~700 fb-1

3. EPR Entanglement Quantum Mechanics:
EPR Paradox:
Quantum Mechanics:
Entangled state  non-separable wave function even for
far apart particles
can not be a “complete” theory
Local realistic theory with “hidden” parameters

4. Bell Inequality Any Local realistic theory with “hidden” parameters
S = |E(a,b)-E(a’,b)| + |E(a,b’)+E(a’,b’)| < 2
(Belle-CHSH Inequality)
[Physics 1, 195(1964); PRL 23, 880(1969)]
Violation  Reject LRT, Confirm QM
Many experiments performed: violation ~established
Entangled photons
[e.g. G.Weihs et al., PRL 81, 5039(1998)]
Entangled Be ions
[e.g. M.A.Rowe et al., Nature 409, 791(2001)] _
[CPLEAR, PLB 422, 339(1998)
KLOE, PLB 642, 315 (2006)]
Also, attempts with K0K0 system

5. Why Y(4S)  B0B0 System _ One of few coherent systems in HEP
Highest energy scale (~10 GeV)
breakdown of QM at high energy ?
Bell Inequality Test : intrinsically impossible
QM to violate B.I. ; x = Dm/G > 2.6  xd = 0.78
Active measurement needed
 Flavor measurement via decay reconstruction = passive
[.A.Bertlmann et al., PL A332, 355(2004)]
Any way to test QM at Y(4S) ?

6. Flavor Asymmetry (as Dt)
Precisely measure Time-dependent decay rate
Compare with Non-QM model
QM:
Same Flavor (B0B0, B0B0): ∝ 1 + cos(DmDt)
Opposite Flavor (B0B0) : ∝ 1 - cos(DmDt) _ _ _
OF-SF
OF+SF
AQM(Dt) =
= cos(DmDt)

7. Non-QM models Local Realism: Pompili & Selleri (PS)
(examples)
Local Realism: Pompili & Selleri (PS)
[EPJ C14,469(2004)]
_ _
“elements of reality” = Flavor & mass (BH,BL, BH,BL)
random jump of Flavor within pair
Spontaneous & immediate Decoherence (SD)
[e.g. PR 49,393(1936)]
Note) Local realistic model with same A(Dt) as QM is possible
[quant-ph/ ]

8. Time-dependent Asymmetry

9. Analysis Method B0  D*ln + Lepton-tag Fully corrected (= true) A(Dt)
~Same as Dm
measurement
( high quality
lepton-tag only)
[PRL,89,251,803(02),PRD 71,972003(05)]
Background subtraction
Unfolding [SVD method]
Fully corrected (= true) A(Dt)
 Direct comparison with (any) theories
Quantitative Test for non-QM model

10. Signal Reconstruction
background
152M BB
6718 OF
1847 SF

11. Results & fit with QM Fully corrected A(Dt): fit with QM
[quant-ph/ ,
submitted to PRL]
Fully corrected A(Dt): fit with QM
152M BB
c2 = 5.2 (11 dof)
Good !
[ fit including WA Dm = (0.496  0.014) ps-1 (excl. Belle/BaBar)]

12. Result: SD & PS SD PS c2 = 174 c2 = 31.3 disfavored 13s
152M BB
c2 = 174
disfavored 13s
over QM
c2 = 31.3
disfavored 5.1s
over QM
Decoherence fraction: l =  0.057

13. Y(3S) Run Dark Matter search: Y(3S)  p+p- Y(1S) [ cc] No sensitivity
DAMA NaI 3s Region
CDMS 04
CDMS 05
WIMPs: good candidate
o% antimatter

14. B ( Y(1S)cc ) ~ 6x10-3 (mc<4.73GeV/c2 ~ mb)
W : relic density
h : Hubble constant
v : 1/20 ~ 1/25
0.1 pb ・ c
<s(ccSM) v >
=  WMAP c q _ c q _
s(ccSM) ~ 18 pb
@ s(SM cc ),
G(U(1S)cc) = fU2MUs(bbcc)
B ( Y(1S)cc ) ~ 6x10-3 (mc<4.73GeV/c2 ~ mb)
PRD 72, (2005) “Invisible quarkonium decays as a sensitive probe of dark matter”
Presented by B. McElrath in BNM-I in KEK Sep, 2006
Previous Upper Limit : < 23x10-3 (90% CL) by ARGUS (1986)

15. Signal of Y(1S)  invisible
fixed energy p+ p-
p+p- recoil mass forms a peak
Y(3S)
No signal left in the detector
Y(1S)
@ 9.46GeV/c2
== mY(1S)
Invisible

16. Y(3S) : best for Y(1S)invisible
No signal
in detector
Y(3S) runs : 2.9 fb-1
(Feb, 2006 : 4days)
s~7nb
No trigger issue
s~4nb
S/N~1/8
sISR~0.02nb
S/N <1/1000
Energy scan by CLEO

17. Special: Loose 2-track Trigger
Trigger eff. 89.8%
(f135)
Trig. effic.: monitored by
prescaled 1-track Trrig.

18. Control sample: Y(3S)p+p-Y(1S)[mm] p+ Y(3S) p- 2.9 fb-1 4901.9±71
signals
498K Y(3S)
 p+p- Y(1S)
11M Y(3S) p+ p-
Y(3S)
~ Signal peak
U(1S) m+ m-

19. Background Suppression+
p -
~ Dominant : Two-photon process ~
Pion opening angle in the CMS
Vector-sum of transverse momenta of 2 pions in the CMS
signal BG
Maximum energy deposit in the calorimeter cluster
Fisher
signal
F < -0.7
reject

20. Backgrounds Y(1S) m+m-, e+e- … (outside of acceptance) p m
Two-photon BG
recoil mass of p+p-
Y(1S) m+m-, e+e- … (outside of acceptance) p m
244 events predictedBr(Y(1S)invisible)=6x10-3

21. B (Y(1S)invisible) < 2.5x10-3 (90%C.L.)
Results
Nsignal = 38 ± 39  0 consistent
B (Y(1S)invisible) < 2.5x10-3 (90%C.L.)
data
Fit BG
Prediction
Br(Y(1S)invisble)=0.6%
2.9 f b-1
at Y(3S)
Prediction is
disfavored
[PRL 98,132001(07)]

22. Prospect l+l- Disfavored by this result at 90% C.L.
Theoretical prediction
continue with
current condition
With super-forward calorimeter & m-detector to reduce peaking BG _
Y(1S)  nn
[Veto Y(1S)  ]
l+l-

23. DM search in B  K(*)nn _ SM Signature: K(*) + invisible Another
SM: BF(BK ) ~4 x 10-6
(Buchalla, Hiller, Isidori) S h
[PRD 63, ]
Sensitive to New Physics
and
also Light Dark Matter
(mS < 2 GeV/c2)
(in loop)
[e.g. C.Bird, PRL 93,201803(2004)]
Signature: K(*) + invisible

24. Experimental Method Tag-side: Full reconstruction B- B+ n Signature :
Y(4S) B- B+ n K+
Signature :
1 particle + invisible
Residual ECL energy
EECL ~ 0
535M BB
Tag-side:
Full reconstruction
641K B 
Charged B

25. Result New ! B(B+  K+nn) < 1.4x10-5 @90% CL 535M BB
FPCP07
1.6 < p* < 2.5 GeV/c
Nb = 20.0  4.0
Nobs = 10
Preliminary
B(B+  K+nn) < 1.4x10-5
@90% CL

26. Constraint on DM
Preliminary

27. Other B  h(*)nn modes _
New !
FPCP07
Preliminary

28. Other B  h(*)nn modes _ New ! UL (@90%CL) < 3.4x10-4 < 1.4x10-4
FPCP07
< 1.4x10-4
Preliminary
< 1.4x10-5
< 1.6x10-4
< 1.7x10-4
< 2.2x10-4
< 4.4x10-4
< 1.5x10-4
< 5.8x10-5

29. B  D*tn New ! B decays including t  sensitive to Charged Higgs
FPCP07
B decays including t  sensitive to Charged Higgs
Always involve > 2 n (Missing E): experimental challenge
B  tn : First Evidence !
[Belle, PRL 97, (2006)]
B  D* tn : Lepton (t) polarization info.
Expected B ~ 1.4% in SM (large)
But, large background (D*(**)ln, D*X)
[e.g. D.S.Hwang EPJ C14,271(2000)]

30. B0  D*-t+n :Reconstruction
Use detector Hermiticity
Full Recon. tag : excellent S/N, but very low efficiency
Signal side
Tag side
Clean signature: D*+lepton
“Inclusive B” reconstruction
Sub-decay modes: D*-  D0p-
t  enn, D0  K+p-/K+p-p0
t  pn, D0  K+p-
Sum all the residuals
SQ=0, no lepton, SNbaryon=0 _ _ _
-0.25 < DEtag < 0.05 GeV
Mtag = [Eb2 – ptag2]1/2
(leptons are too soft : t  mnn not used) MC

31. Validity Check Tag side “Inclusive” reconstruction
Control sample : B0  D*- p+
All tag-side cuts applied

32. Signal side: Bkg suppression
t  enn mode _
D*e n
Main background: B  D*e n
D**e n
other B
continuum
signal
most powerful

33. Signal side: Bkg suppression
t  pn mode
Main background: Hadronic B, Continuum
M0 > 1.5
M2W – M2M – M2t + M2p > 0
Visible energy: Evis < 8.3 GeV
Pion energy: Ep > 0.6 GeV
No KL’s in the event : N(KL) = 0
Number of rejected tracks: Nbad < 4
(bad inpact parameters)
only two n’s  more kinematic constraint
equivalent to |cosqn1n2 | < 1

34. Signal side: Bkg suppression
Before
After Bkg. suppression MC MC
signal
other D*tn
modes
tenn _
(B =1.4% assumed)
D*e/m n
D**e/m n
other B MC MC
c-continuum
uds-continuum
t  pn
peaking part
treated as signal

35. Results B (B0  D*-t+n ) = (2.02  0.36) % First Observation !
Extended ML fit: Signal = Crystal-Ball, Bkg = Argus + peaking
Shape params fixed to MC, peaking fixed to expectation
t(enn), D(K+p-)
t(enn), D(K+p-p0)
t(pn), D(K+p-) _ _
Ns=12 +6 -5
Ns=30
+10 -9
Ns=20 +6 -5
Simultaneous fit:
Ns=60
+12
-11
6.7s(> 5 w/ sys)
First Observation !
B (B0  D*-t+n ) = (  0.36) %
+0.40
-0.37
Preliminary

36. Systematic Error Total 18% for combined BF (*) Preliminary
(*) Peaking background
1.2
+1.6
-1.5
5.0
+2.6
-2.2
-1.0
+3.6
-3.2

37. Cross Checks tenn tpn Fit to signal side variable Preliminary
Mtag >5.27
signal
background
Preliminary
cosqn1n2
tpn
Mtag >5.275
Mtag <5.26
signal
other
D*tn
background
Fit to signal side variable

38. Checks: Look-back plots
Distribution of a variable in signal-box (“N-1” cuts)
data
signal
other D*tn
modes
background

39. B (B0  D*-t+n ) = (2.02  0.36) % First Step ! B  D*t+n B  Dt+n
+0.40
-0.37
Preliminary
Consistent with SM estimations
Need more precise measurements & updated SM predictions
to obtain useful NP constraint
First Step !
B  D*t+n
B  Dt+n
B+  t+n
95%CL interval
(assume fL same)
Super B Factory
[M.Tanaka Z.Phys. C67,321(1995)]

40. Prospects: H± sensitivity
Super B Factory
B g D- t +n
B g t +n
50ab-1
50ab-1
5ab-1
Preliminary

41. Crab Cavity Study Crab Crossing  Head on collision
increase Luminosity by ~2
with Crab
w/o Crab
simulation by K.Ohmi
(strong-strong)

42. Crab cavity Installed Superconducting Crab Cavity
Jan-2007: Crab cavity installed (1/ring at Nikko area)
13-Feb-2007: Beam study started
Superconducting Crab Cavity
HER
LER

43. How works w/ 1 cavity/ring ?IP
crab
cavity
2 cavities per ring
orbits of bunch head and tail

44. How works w/ 1 cavity/ring ?
bunch head
bunch tail IP
crab
cavity
crab
cavity
1 cavity per ring
beam
beam
orbits of bunch head and tail

45. Observation of Crabbing !
Crab OFF
Crab ON
＋180° 0°
Crab ON 0°
＋180°
Horizontal
HER(1.43MV)
LER(0.9MV)
Streak camera
schematics
Hamamatsu C5680

46. Specific Luminosity

47. Plan / Goal May-2007 (Golden week): wormed-up once and cooled-down
14-May: Beam operation resumed
Study : performance at higher bunch current
& at higher total current
Beam-bean tune xy > 0.1
Important Step toward Super-KEKB

48. A few words on Super-KEKB

49. Consensus in J-HEP community
News
Consensus in J-HEP community
Japanese HEP community reached the following agreement in October 2006 after a long discussion.
First priority is to realize ILC, and its R&D should be boosted. On the other hand, flavour physics programs (SuperKEKB, and K and n program at J-PARC) should be carried out as physics programs before ILC (i.e., 2010’s).
[M.Yamauchi’s recent talk]

50. Recommendation by Belle-PAC
The committee provided strong endorsement to SuperKEKB in the meeting in April 2007.
This is also an important support from the int’l community.

51. J-PARC n, n construction
2006
2008
2010
2012
2014
2016
2018
2020
J-PARC n, n construction
J-PARC R&D
J-PARC n, K experiment
J-PARC n, m experiment
upgrade
Budget transfer
PF upgrade PF
Budget transfer
ERL prototype
ERL construction
experiment
KEKB
ILC R&D
ILC construction
experiment
Budget transfer
Option 1
KEKB
ILC R&D
ILC construction
experiment
KEKB upgrade
Budget transfer
Option 1’ 51

52. Remarks Letter of Intent for Super-KEKB (Jan-2004)
2008 will be a critical timing for KEKB/SuperKEKB.
J-PARC construction will be completed.
Belle accumulates 1000/fb.
PEP-II/BaBar will be shutdown.
It is likely that KEK takes some decision soon.
Machine: KEK + contributions from the world
Detector: perfectly open to the new collaboration
Hope to strengthen collaboration with Western SuperB.
Letter of Intent for Super-KEKB (Jan-2004)
Progress on Physics cases / Detector / Accelerator
Update of LOI in progress
welcome to join !

53. Proposed schedule SuperKEKB ~8×1035 Lpeak~1.5×1034 1.5 - 3×10346
~10B BB and t+t- every year
Integrated luminosity (ab-1)
2 yr shutdown for upgrade 4
Crab cavity installation
Belle is here.
0.7ab-1 2
2000
2002
2004
2006
2008
2010
2012
2014
Calendar year

54. Summary Diversity of Analyses & Data [Y(3S/5S)] EPR entanglement
Confirmed QM, disfavor PS, DS with >5s
Light Dark Matter Search at Y(3S)
B (Y(1S)invisible) < 2.5x10-3 (90%C.L.) < Theory
Also, searched by B g K(*) n n
B g D*- t +n : First Observation ! (5.2s)
Crab Cavity installed : study in progress
step toward SuperKEKB _
welcome to join !