1. Physics Results of Belle and Prospects for Belle II
Y.Sakai KEK
Reference for physics prospects
Physics at Super B Factory [arXiv: ]
SuperB Progress Report [arXiv: ]

2. Physics at B factory B physics (~1.1nb) - CP violation & CKM
- Rare decays
Charm physics (~1.3 nb)
t physics (~0.9nb)
two-photon processes
New Resonance
- ordinary & exotics B
Y(4S) _ B
c t- _
c t-
Variety of Physics !
Complement/Cooperative with t/Charm factory !

3. Goal/Milestones of B-factory
Step1
2001 summer !
Discovery of CPV in B decays
2008
Step2
Precise test of KM and SM
Step3
Search for NP
Hints of NP
Establish procedures
(SUSY, Extra-dim…)
SuperB-factory
~50 times more data
(higher luminosity)

4. CP Violation Difference between particle & anti-particle
(matter & anti-matter)
Universe: almost “matter” only (no anti-matter)
Big-Bang  N(particles) = N(anti-particles)
Sakhalov’s 3 conditions (1967):
1. baryon number violation
2. CP violation
3. existence of non-equiblium
CPV is a key for Existence of Universe & us !
Andrei Sakharov ( )

5. Kobayashi-Maskawa: CPV
CPV: due to a complex phase in the quark mixing matrix
CKM matrix dj uk W-
Vkj
Unitarity
triangle *
Wolfenstein representation
Vud Vub
2 (a) *
Vtd Vtb
3 (g)
1(b)
Vcd Vcb *

6. KEKB Accelerator 8 GeV e- x 3.5 GeV e+: 22mrad crossing KEKB Belle
~1 km in diameter
Mt. Tsukuba
KEKB
Belle
e+ source
Ares RF
cavity
Belle detector
8 GeV e- x 3.5 GeV e+: 22mrad crossing
Lpeak = 2.11x1034
Integ. Lum. ~1040 fb-1

7. Peak Luminosity
2.11x1034
1.21x1034
>1fb-1/day
>1 M BB _

8. Data at B-factories (have to switch to new units, 1 ab-1) (fb-1) _
772MBB
“Intense Analysis Phase” _
487MBB

9. charged particle tracking Muon / KL identification
Belle Detector
, p0 reconstruction
e+-, KL identification
K/p separation
Aerogel Cherenkov Counter
n = 1.015~1.030
Electromagnetic Calorimeter
CsI(Tl) 16X0
3.5 GeV e+
TOF counter
K/p separation
charged particle tracking
8.0 GeV e-
Central Drift Chamber
momentum, dE/dx
50-layers + He/C2H6
B vertex
Muon / KL identification
Si Vertex Detector
4-layer DSSD
KL m detector
14/15 layer RPC+Fe

10. The Belle Collaboration
Nagoya U.
Nara Women’s U.
National Central U.
National Taiwan U.
National United U.
Nihon Dental College
Niigata U.
Osaka RCNP
Osaka City U.
Panjab U.
Peking U.
PNNL
Riken
Saga U.
USTC
Seoul National U.
Shinshu U.
Sungkyunkwan U.
U. of Sydney
Tata Institute
Toho U.
Tohoku U.
Tohuku Gakuin U.
U. of Tokyo
Tokyo Inst. of Tech.
Tokyo Metropolitan U.
Tokyo U. of Agri. and Tech.
Toyama Nat’l College
Torino
Wayne S.U.
VPI
Yonsei U.
BINP
Bonn U.
Charles U.
Chiba U.
U. of Cincinnati
Fu-Jen C.U.
Giessen U.
Gyeongsang Nat’l U.
Goethingen
Hanyang U.
U. of Hawaii
Hiroshima Tech.
IHEP, Beijing
IHEP, Moscow
IHEP, Vienna
Indiana U.
ITEP
Kanagawa U.
KEK
Karlsruhe U.
KISTI
Korea U.
Krakow Inst. of Nucl. Phys.
Kyungpook Nat’l U.
EPF Lausanne
Jozef Stefan Inst. / U. of Ljubljana / U. of Maribor
Luther
U. of Melbourne
MPI
15 countries, ~60 institutes, ~400 collaborators

11. CPV in B0 decays = J/y B0 B0 K0 _ _ V*cb c b t b d s d V*td _ A fcp B0-
Sanda
Bigi
Carter = B0
fcp
mixing
Decay: A
V*td _ t d b w B0 _ d b c s w B0
J/y K0
V*cb
Initial: B0 B0 _
Interference
Direct decay
Mixing + Decay
Oscillation
Weak
Phase
difference
frequency: Dmd
(BH, BL)
Decay-time dependent CPV

12. CPV in B0 decays = 2(a) 3(g) 1(b) _ A fcp B0 A - Sanda Bigi Carter
mixing
Decay: A
mixing
1(b)
2(a)
3(g)
Vtd Vtb
Vcd Vcb
Vud Vub *
-hf sin2f1 sin(Dmd Dt) _
Dt (decay time)[ps] B0 B0
Prob.
ACP
sin2f1
Decay
(hf : CP eigenvalue)

13. Time-dep CPV Measurement
Flavor-tag
(B0 or B0 ?)
J/(f,h’) KS e e z
t=0
fCP
Vertexing
Reconstruction
eeff ~30%
sDt~140ps B0
B0-tag
Dt  z/cbg
fit
Extract
CPV
bg=0.425 (KEKB)
0.56 (PEP-II)
same analysis method applied for all modes

14. sin2f1 : CPV observation First observed CPV in B (2001) 1137 events
B0 tag _
1137
events
B0 tag
2001
Asymmetry
31M BB
First observed CPV in B (2001)

15. sin2f1 : Precision meas. 14000 signals 2006 535M BB 3.4% error ! _
0.6870.0280.012
0.670  0.023
B0 tag _
14000
signals
2006
535M BB
3.4% error !

16. Measurement of CKM Complete test of KM & SM 2 3 1 Over constraint !
Determination
of UT
Complete test of KM & SM
B pp, rp, rr *
b u l-n *
Vtd Vtb
Vud Vub 2
B0-mixing (Dmd)
B p/r l n
(a)
B rg 3
(g) 1
(b)
B-  DcomK- *
Vcd Vcb
B0 D(*)+p-
B0  (cc)K(*)0
b  c l-n
B0  D*+D(*)-(K)
B  D(*)l n
Over constraint !
B experiments can provide all measurements !

17. Verification of KM for CPV
All consistent
CPV:
caused by a
single phase of
CKM matrix
Verified by B-factory
experiments
2008 Physics Nobel Prize

18. Next Challenge New Source of CPV should exists
In spite of Great Success of SM, there must be
New Physics beyond SM at High Energy scale
(SM is valid effective theory at current E-scale)
Observed CPV in SM is not enough
to explain matter dominance of Universe
[>O(1010)] !
New Source of CPV should exists
(beyond SM)
One of Next important goals of Flavor Physics
Energy Frontier
Note) NP effects appear in Flavor Physics in various way !

19. Search for New Physics SuperKEKB KEKB CPV in B Rare B decays
provide Powerful tool for Search NP ( New Phase )
[ bsqq tCPV]
Rare B decays
excellent opportunities for NP search
Loop diagram
Penguins [bs(d) g, bs(d) l+l-]
Key
Decays involving t ( H)
ANP ~ ASM (small/forbidden)
t Decays (Lepton Flavor Violation = NP) : B-factory = t-factory
Establish analyses
Hint of NP
SuperKEKB
KEKB

20. NP : Precise CKM
Still ~10% room
for NP
50ab-1

21. - New Source of CPV: b  sqq X b s d t b f,h’.. f,h’.. s d - KS KS_ B0 + KS KS
Vts Vtb *
SM: bs Penguin
phase = (cc) K0 -
+ New Physics
with New Phase
Sbs ¹ Sbc , ADCP can ¹ 0 _
“b  ccs: sin2f1” (SM reference) deviation 21

22. Summary of New CPV search
B0 J/yK0　
Reference point of SM
No clear deviation seen
in all modes (1~2s)
New CPV effect can be
seen with much larger
data
Super B-factory

23. Compelling measurement in a clean mode
SuperKEKB prospect
B  fK0 at 50/ab with ~present WA values MC
J/K0
fK0
bs
This would establish the existence of a NP phase in bs penguins.
δ(Sbs) ~ 50ab–1
Prospect
Compelling measurement in a clean mode 23

24. Kπ Puzzle in B⁰/B⁺ CP Violation
B⁰  K⁻π⁺
B⁰  K⁺π⁻
B⁻  K⁻π⁰
B⁺  K⁺π⁰ B⁰ B⁺ _
Expected to be same
DAKp = A(K+p−) − A(K+p0)
= −0.147 ± 0.028
S.-W. Lin et al. (The Belle collaboration),
Nature 452, 332 (2008).
5.3σ deviation
 Hint of NP ?

25. Solutions to the DAKp Puzzle
See Nature commentary by Michael Peskin T T
Expectation from current theory
T & P are dominant  DAKp ~ 0 P C
PEW T P
Enhancement of large PEW  New physics
Enhancement of large C with large strong phase to T  strong inter. !?
Chiang et. al. 2004
Li, Mishima & Sanda 2005
Yoshikawa 2003; Mishima & Yoshikawa 2004;
Buras et. al. 2004, 2006; Baek & London 2007;
Hou et. al. 2007; Feldmann, Jung & Mannel 2008
Can this issue be resolved in a model-independent way by experiment ?

26. Model-indep. Sum Rule A(K0p0) B →Kp A(K0p+) Sum rule proposed by:
HFAG, ICHEP08
dA(K+p0)
sum rule
A(K0p+)
measured (HFAG)
expected (sum rule)
Sum rule proposed by:
M. Gronau, PLB 627, 82 (2005); D. Atwood & A. Soni, Phys. Rev. D 58, (1998). 26

27. SuperKEKB prospect Belle II, 50 ab-1 Important to measure A(K0p0)
dA(K+p0)
Important to
measure A(K0p0)
precisely
sum rule
A(K0p+)
B →K0p0 :
main syst. uncertainty
full systematics treated
as non-scaling (conservative) 27

28. Charged Higss Hunting B-Factory:
Variety of Modes sensitive to Charged Higgs
Some are only possible at B-Factory

29. Inclusive b  s g SM 657M BB Fully Inclusive measurement Data
Background
subtracted

30. b  s g Summary

31. H+ Search: B+ +  (Decays with Large Missing Energy)
Sensitivity to new physics from charged Higgs
The B meson decay constant, determined by the B wavefunction at the origin
(|Vub| taken from indep. measurements.)

32. B->ν : Experimental Challenge
(4S) B- B+ n e+ ne
B++,
+e+e
B-X
Always > 2 neutrinos appear
in B  t n decay _
Signature : 1 track +invisible
Experimental Challenge !

33. B->ν : Experimental Challenge
(4S) B- B+ n e+ ne
B++,
+e+e
B-X
Tag-side:
Full reconstruction
Also for
B  D(*)tn
B  Knn _
Can be measured only by B-Factory !

34. B->ν Results
2.8s

35. B  D(*)tn 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)]
Always involve > 2 n (Missing E):

36. B  D(*)tn Results First Observation ! 657M BB B0  D*-t+n
[PRL 99, (2007)]
First Observation !
[PRD 82, (2010)]

37. B  D(*)tn Summary

38. Constraints on charged Higgs
U. Haisch, hep-ph/ ; ATLAS curve added by Steve Robertson
Also see (MSSM),D. Eriksson,F.Mahmoudi and 0.Stal

39. - D0-D0 Mixing Quark level: Box diagram SM box: O(10-9)
(~ B0-mixing)
SM box: O(10-9)
+Long distance: O(10-3~10-2)
x=Dm/G
y=DG/2G
Large mixing, |x|>>|y|, CPV  New Physics !
Only mixing with up-type quark
complementarity to down-type FCNC

40. D0-mixing : yCP Decays to CP eigenstates D0 → K+K- / p+p-
“lifetime” difference
First Evidence (2007) !
PRL 98, (2007), 540fb-1

41. D0-mixing : Wrong sign D0  K-p+ : normal decay
D0  K+p- : Mixing Signal
But, two sources
need decay-time analysis
to extract D0-D0 mixing _
“Wrong Sign”
400fb-1
PRL 96, (2006)
(0,0)
CL 96.1%
BaBar, PRL 98, (2007), 384fb-1 1s 2s 3s 4s 5s
likelihood
contours
3.9s
CDF, PRL 100, (2008), 1.5fb-1

42. D0-mixing : t-dep. Dalitz
D0  KSp+p- t
most precise x meas.
y (%)
x (%)
Belle, PRL 99, (2007), 540fb-1

43. D0-mixing : Summary HFAG x~y~1% ~ SM limit ! Mixing parameters
global fit to observables,
only KK/pp, Kp and Kspp
projected sensitivities included
(no external constraints, e.g. dKp)

44. D0-mixing : prospect Mixing parameters 1 s @ 50 ab-1 1 s @ 50 ab-1
A.G. Akeroyd et al.,
arXiv:
Mixing parameters
global fit to observables,
only KK/pp, Kp and Kspp
projected sensitivities included
(no external constraints, e.g. dKp)

45. Constraints from D0-mixing
4th generation of fermions
R-parity violating SUSY c u b’ W+ W- D0
Vcb’
Vub’* D0
|Vub’Vcb’|
mb’ [GeV]
allowed area
lines of
constant |x|
R couplings
[GeV]
allowed area
lines of
constant |x|
E. Golowich et al., PRD76, (2007)
E. Golowich et al., PRD76, (2007)

46. Hints/Sensitive to NP ….. CPV in b  s Penguin？ A(B  Kp) Puzzle
Forwad-Backword Asy,.B  K*ℓ+ℓ−
C7=−C7SM SM
CKM Unitarity Triangle
Large D0-mixing
fL(B  VV) ≠ 1
Theoretical calculations
using Vub, Dmd,eK
Direct
measurement
tree
…..
penguin

47. Identification of NP type
Identify by the pattern of deviations from SM
SUSY models
mSUGRA
MSSM+R
SU(5)+R
U(2) FS
degenerate
non-degenerate
ACP(s) ✔
S(K*)
S()
S(KS)
S(BsJ/ )
e ?

e …
Measurements …
✔: deviation from SM
[based on T.Goto et.al. PRD77, (2008)]

48. Physics at Super B-factory
is “DNA chip of
New Physics”
+ LHC,…
 D. Hitlin

49. Energy Frontier vs Flavor Physics
Direct Production by High Energy Coll.
Virtual Production via Quantum Eff. q ~ s p p b c ~ g g ~ q ~ c ~ ~ n q _ q l-
Tunnel effect
Luminosity
Frontier
Energy Frontier
Diagonal terms
Off-diagonal terms
Higher Energy Scale
Can be searched
(even if LHC finds
no New Physics)

50. (Luminosity Frontier)
LHC observes NP in TeV scale
Complementarity of
Flavor Physics
(Luminosity Frontier)
& Energy Frontier
Identify NP type SUSY, Extra Dim. Little Higgs,..?
Mechanism of Symm. Breaking
CPV via NP
Era of NP Exploration
SU(5)+R
degenerate
MSSM+R
degenerate
SU(5)+R
non-degenerate
New Physics
Belle II = Compass
MSSM+R
non-degenerate
U(2)FS
Higgs
Standard Model
top
Energy Frontier
Luminosity Frontier
W, Z
Map
S.Nishida

51. Search by Flavor Physics in Dark
In case of No New Physics in TeV scale
FCNC process currently gives various limits on NP ⇒ further explore NP
Search by Flavor Physics in Dark
SU(5)+R
degenerate
MSSM+R
degenerate
SU(5)+R
non-degenerate
New Physics
Belle II = Compass
MSSM+R
non-degenerate
U(2)FS
Higgs
Standard Model
top
Energy Frontier
Luminosity Frontier
W, Z
Map
S.Nishida

52. Comparison with LHCb
Sta
Complementary !

53. Summary SuperB-factory Discovery of CPV in B decays
Step1
2001 summer !
Discovery of CPV in B decays
2008
Step2
Precise test of KM and SM
Step3
Search for NP
Hints of NP
Establish procedures
(SUSY, Extra-dim…)
LHC: New particle, masses
SuperKEKB: couplings
Understand NP need Both
SuperB-factory
~50 ab-1 data (L ~1036cm-2s-1 )

54. Discovery of New Resonances
“Exotic Hadrons”
X(3915), Y(4350)
Charged Yb
Z(4050),Z(4250)
Y(4660)
Y(4008)
Z(4430) d c u u c
Integrated Luminosity
DsJ(2860)
DsJ(2700)
Xcx(3090)
Y(4320)
Tetraquark
cluster
cc2’
X(3940), Y(3940)
Neutral c g
Y(4260) u c
Sc* baryon
triplet
X(3872)
Hybrid
D0*0 & D1*0
DsJ(2317/2460)
hc’ & e+e-cccc

56. SM CPV: too small CPV Phase WMAP Too Small in SM masses too small !
Why? Jarlskog Invariant in SM (need 3 generation in KM)
Normalize by T ~ 100 GeV
masses too small !
is common (unique) area of triangle
in SM
CPV Phase
[W.S.Hou]

57. CPV in B0 decays (General)
Vtd Vtb
Vcd Vcb
Vud Vub * B0 Dt
made by H. Miyake
= S sin(DmDt) + A cos (DmDt) A CP
Mixing induced CPV
Direct CPV A B0
fｃｐ =
fｃｐ B0
mixing - B0
q/p A B0

58. f1 Measurement J/y B0 B0 K0 2(a) 3(g) 1(b) _ _ * Vud Vub Vtd Vtbc s w B0
J/y K0 _ t d b w B0
V*cb
V*td
V*td
1(b)
2(a)
3(g)
Vtd Vtb
Vcd Vcb
Vud Vub *
= - xcpsin2f1 sin(DmDt) +A cos (DmDt) A CP
Mixing induced CPV
Direct CPV
xCP : CP eigenvalue 0
First observed CPV in B (2001)

59. A(K0p0) measurement BKS 0 Signal +1st BKL 0 Signal
2855257 (3.7σ incl. systematics)
These modes will be very difficult at a hadron machine
3-d fit gives a signal of 65737 events
Use flavor tagging to distinguish B0 and anti-B^0

60. B->ν : Tension
measurements
Indirect fit
prediction
sin2f1

61. and more…