1. SuperKEKB Physics Reach
@ 50 ab−1
S. Nishida
KEK
BNM2008
Jan. 24, 2008

2. Contents Introduction B  Dtn, tn Various Observable
New CP Phase, Right-handed current, LFV
Precise Measurement of Unitarity Triangle
Summary

3. Introduction

4. Target: 50 ab-1 (hopefully)
B Factory
Super KEKB (plan)
Belle + BaBar > 1 ab-1
Target: 50 ab-1 (hopefully)

5. Present CKM Measurement
Kobayashi-Maskawa (KM) theory for the CP violation
has been well confirmed.
The role of Super B factory will be the study of New Physics (NP).

6. Flavor Physics
Grand questions in flavor physics
Why three generations ?
Why masses and mixing parameters with strange patterns ?
Why did antimatter disappear in the early universe ?
...
The Standard Model (SM) does not give answers
Profound principles (of Gauge, Relativity, Quantum)
However, “Flavor Principle” is missing
These exciting questions will remain unanswered even if SUSY is found at LHC.
Long-term step-by-step experimental approach in flavor physics needed to address these grand questions.

7. Quark Flavor Physics
by Hazumi

8. Studies at Super KEKB New CP-violating phases ?
tCPV in bs transition.
New right-handed currents ?
photon helicity in bs
Effects from new Higgs fields ?
B, D
New flavor violation ?
LFV ()
New flavor symmetry to explain the CKM hierarchy ?
Precise unitarity triangle measurement
Direct detection of NP in flavor physics.
Measure properties of NP, if NP is found in LHC.
Constrain NP at higher energy scale (if NP not found).

9. Effect from new physics field
B, D
Effect from new physics field

10. “B Meson Beam”
By fully reconstructing one B meson, we can obtain “single B meson beam”
Approach unique at e+e- collider.
Powerful tool to study B meson decays to neutrino and tau. B e-  e+ B p D
full reconstruction
0.2~0.3% for B+
|Vub| from semi-leptonic decays.
B  
B  D
B  K : 5 discovery with 33 ab-1.

11. B decay constant  Lattice QCD+
Possible contribution of charged Higgs (H+) in tree level.
In the SM:
B(B) = (1.6 ± 0.4)×10-4
H+? W+ B+ u t
B decay constant  Lattice QCD
More than 1 neutrinos in the final states (can be measured only in B factories).
fB and |Vub| should be known precisely.

12. Constraint on mH and tan plane:
B  
Belle result with 414 fb-1:
Signal +
background
0.56
0.49
0.46
0.51
B(B++) = (1.79 ± ± )×10-4
Constraint on mH and tan plane:
Background
Btn
Signal
To estimate the charged Higgs mass reach at superB, experimental error is assumed to scale with luminosity.

13. B   Prospects at 5 ab−1 and 50 ab−1 5 discovery region at 5 ab−1
1000
1000
m(H) ~ 400
@ tan = 30
m(H) ~ 300
@ tan = 30
H± mass (GeV)
H± mass (GeV)
present
exclusion
region
100
100
tan
tan
fB = 5%, |Vub| = 5%
fB = 2.5%, |Vub| = 2.5%

14. It is essential to reduce these errors to a few % level at 50 ab−1
95.5% exclude region at 5 ab−1
95.5% exclude region at 50 ab−1
1000
1000
m(H) ~ 545
@ tan = 30
m(H) ~ 353
@ tan = 30
H± mass (GeV)
H± mass (GeV)
100
100
tan
tan
fB = 5%, |Vub| = 5%
fB = 2.5%, |Vub| = 2.5%
Note: The error from fB and |Vub| are comparable to experimental error.
It is essential to reduce these errors to a few % level at 50 ab−1

15. B  Dtn Semileptonic decay (with t)
D/D ratio sensitive to charged Higgs.
Some sensitive observables (e.g.  polarization)
Good cross check for B  tn
H-b-u vertex by B  tn
H-b-c vertex by B  Dtn
H-b-t vertex by LHC direct search
tan
=50
tan = 20 SM
c.f.) BaBar 209 fb−1
tan
=10
B(B  Dtn)
= (0.86 ± 0.24 ± 0.11 ± 0.06)%
300
H± mass (GeV)

16. B  Dtn 50 ab−1 5 ab−1 Prospects 5 ab−1 B(B+D0+) : 7.9%
Similar to Btn
5 ab−1
B(B+D0+) : 7.9%
MH > MWtanb/11
50 ab−1
B(B+D0+) : 2.5%
MH > MWtanb/5

17. Lepton Flavor Violation
Various Observables
New CP phases in bs
Right-handed current
Lepton Flavor Violation

18. sin2f1 reference (J/K0) is very clean:
New CP Phase in bs
Many New Physics models contains new source of CP violation.
bs transition is a good place to search for new CP phases. c w
J/ b b s
, ’ c B0 t g W B0 s s d
KS/KL d s
KS/KL d d
sin2f1 reference (J/K0) is very clean:
precision
~ ab−1

19. New CP Phase in bs
Present status: tree-penguin difference is now 0.1σ
the difference is 2.2σ if we exclude this result: simple average is too naïve because the error is non-gaussian
recent QCDF estimates
need to measure mode by mode
a few % uncertainty
in good modes
sin21eff-sin21

20. Physics Reach in bs
Sensitivity at superB is estimated based on Belle’s 492 fb−1 result.
50 ab−1
present syst. error is categorised as reducible and irreducible error.
0.2
KSKSKS
KS
0.02
’KS

21. Expected asymmetry for
Physics Reach in bs
Expected asymmetry for
J/KS (S=0.68) and KS (S=0.39)
SuperB can measure the deviation of O(0.01).
Understanding of hadronic uncertainty.
5 ab−1
50 ab−1

22. Right-handed current mb ms SM electroweak is purely left-handed.
photon from bs is almost left-handed.
Right-handed current is a signature of New Physics.
Interference of left- and right-handed amplitudes may lead to large mixing induced CP violation in radiative B decay. mb ms
SM expectation
S ~ −2(ms/mb)×sin2f1
Possible deviation from SM
O(1): Warped extra dim.
O(1): L-R symmetric model
O(0.1): SUSY SU(5)
NP with different
chiral structure makes
a large difference
Note: strong interaction may enhance S up to 0.1 even in SM

23. Right-handed current TCPV in B  KS0 at super B.
TCPV in B  0 at super B. 1
Recent Belle result is not taken into account 1
K*0 S
other
KS0 S BF
1.3×10−6
0.5×10−6
0.1
0.1
KS0 total
0.1 10 50
0.1 10 50
Luminosity [ab−1]
Luminosity [ab−1]
S(0) = 50 ab−1
S(KS0) = 50 ab−1
Can reach to the level of hadronic uncertainty

24. Right-handed current S(BKS0) in SUSY general mixing framework dRL
dRR
SuperKEKB (50/ab)
Other exp. constraints (Bs mixing, Br(bsg)) taken into account
J. Foster, K. Okumura, L.Roszkowski, for SuperKEKB physics book update

25. Right-handed current Other analyses sensitive to right-handed current
B  K0+0, B  K+-0
Angle between  and K plane (resonance dependent).
B  K* with   e+e- (conversion)
Angle btw K plane and e+e- plane.
photon conversion analysis
angle resolution is estimated to be ~23
efficiency ~0.36% (can be increased by adding more material)
measurement 2 ~ 4 level (even with maximal right-handed 50 ab−1
need more study (e.g. adding low q2 K*e+e- events)

26. other variable: BF ratio btw K and Kee (>1 might be NP)
AFB in BK*ℓℓ, Xsℓℓ
AFB (Forward-backward asymmetry)
Good electroweak probe for bs.
Sensitive to C7, C9, C10 Wilson coefficients. (c.f. wrong sign C7 is allowed by bs)
q0 (the point with AFB=0) is sensitive to New Physics.
SM: q02 = (4.2±0.6) GeV2
q0  C7/Re(C9)
AFB for bsℓℓ
other variable: BF ratio btw K and Kee (>1 might be NP)

27. Integrated Luminosity (ab−1)
AFB in BK*ℓℓ, Xsℓℓ 30 MC
Error(%) 20 10
C10 C9 5
5 ab−1 3 C7 1
C9, C10 q2 independent terms can be determined with accuracies of 11% and 14% (4% and 4%), respectively, at 5 ab−1(50 ab−1). 10
100
Integrated Luminosity (ab−1)
q0 ~ 11% (5%)
Note: Xsℓℓ is better to avoid form factor uncertainty (experimentally challenging).

28. bs and bsℓℓ at SuperB
bd
Many measurements
sensitive to NP!!
bs
bs
bd
BXd
@5 ab−1

29. Lepton Flavor Violation
Large LFV in  decay of O(10−7~10−9)
in SUSY + Seesaw, SUSY GUTs .
Br() etc. can be reached to O(10−7~10−9) in super B factory.

30. SUSY Breaking at SuperB
T. Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanaka,
hep-ph/ , also in SuperKEKB LoI
Representative SUSY scenarios a la SUGRA
Similar SUSY
mass spectra
(hard to
distinguish) 1 2 3 4

31. SUSY Breaking at SuperB
S(KS), S(KS0), ACP(bs), B(bs), B().....
useful to distinguish NP models.

32. SUSY Breaking at SuperB
“DNA Identification” of New Physics from Flavor Structure

33. Precise Measurement of Unitarity Triangle

34. Measurement of 2 B  , ,  +/+ +/+ -/- -/- d b d b u u u
useful for measurement of 2 w w d
+/+ b d b
+/+ t g B0 u B0 u u d u d
-/-
-/- d d
ACP(t) = S sin(mt) + A cos(mt)
If there was no penguin diagram:
S = -sin(22), A = 0
In reality, A  0 and
(where  can be determined by isospin analysis)

35. time-dependent isospin analysis
Measurement of 2
B  
B  
5 ab-1
5 ab-1
50 ab-1
50 ab-1
time-dependent isospin analysis

36. Measurement of 2 B   5 ab-1 All combined 50 ab-1
50 ab-1 with S(00)
~ 1
@50 ab-1
S(00) can be measured by using photon conversion 50 ab-1)
8-fold  2-fold ambiguity.

37. Measurement of 3 Methods to measure 3
Time dependent analysis of B-  D(*)- to measure sin(21+3).
B±  D0CPK± (GLW method).
B-  D(*)-K(*)- (ADS method).
Dalitz analysis of B±  D(*)K(*)±.
r (Cabibbo-suppressed /
-favored ratio) needs to be input. Result depends on r.
5 ab−1
50 ab−1
B-  D(*)-
18 6
D*K + DK
16 5
Dalitz 7
2.5
All combined 2
Theoretically clean (<1%), but dominanted by statistics even with 50 ab-1
Good statistical power. D model from charm factories

38. Unitarity Triangle 0.5 ab−1 (Belle)  (SuperBelle) 50 ab−1  

39. Generic NP Constraints
SuperKEKB (50 ab−1)
Belle (~0.5 ab−1)
2d (rad)
2d (rad)
rd2
rd2
Mixing amplitude: M = rd2MSMexp(-i2d)

40. Before going to Summary

41. Summary

42. Summary
a few %
at 50 ab−1

43. Summary

44. In Super B, we can/must perform O(1%) precision measurement.
Target at SuperB
Present B factories have been provided many results.
But, most results have been rather “rough”.
Observation of some modes, first measurement of….
Typical error is O(10%)
0.5 ab−1
50 ab−1
???
In Super B, we can/must perform O(1%) precision measurement.
This is a challenge.
Assumed “scale error to luminosity” doesn’t work without effort.
Smaller systematic (and theoretical) error everywhere.
But, a step to reach beyond the SM in flavor physics.

45. Summary Super KEKB pursues flavor physics
Precise measurement of Unitarity triangle
Information on New Physics
New CP phase in bs, right-handed current
Effect from Higgs (, D)
Lepton flavor violation ....
Useful to distinguish New Physics models.
Measurements complementary to LHCb.
With 50 ab−1, many measurements can reach to the level of theoretical (or unavoidable systematic) uncertainty.
complementary to energy frontier expermients
and
essential to particle physics

46. Backup

47. Past News at Belle Exciting results every year ! Evidence for
D0 mixing
Observation of direct CP
violation in B  p+p-
Evidence for B  tn
Observation of b  dg
Evidence for direct CP
violation in B  K+p-
Exciting results
every year !
Beginning of b  s saga
CP violation in B  fKs, h’Ks etc.
Observation of CP violation
in B meson system
Observation of B  K(*)ll

48. What is next with B Physics ?
If new physics at O(1)TeV…
It is natural to assume that the effects are seen in B/D/t decays.
Flavour structure of new physics?
CP violation in new physics?
These studies will be useful to identify mechanism of SUSY breaking, if NP=SUSY.
Otherwise…
Search for deviations from SM in flavor physics will be one of the best ways to find new physics.

49. “Synergy” with LHC (etc.)
Role of SuperB
LHC will (hopefully) find some New
Physics, but may not have enough
information to determine the nature of
New Physics.
B physics
LHC LC
LFV
EDM
Muon g-2
K physics
Charm physics
(Okada)
Super B Factory provides many
observables / clean measurements.
New CPV phase
Kll, K
Lepton flavor violation ( decay)
“Synergy” with LHC (etc.)
The information will be essential to distinguish various New Physics senarios.
The Super B may find New Physics but may not have
enough information to determine its nature,
In this case, the LHC and linear collider may be needed
to distinguish the underlying new physics model.

50. good discovery channel at an early stage of SuperKEKB
B  , e
Precise B   / mn lepton universality test.
Higgs effect itself is universal. RHtn = RHmn
Good probe to distinguish NP models. SM
Br(tn)=1.6x10-4
Br(mn)=7.1x10-7
Br(en)=1.7x10-11
~50 5ab-1
~500 50ab-1
3s at 1.6ab-1
5s at 4.3ab-1
Significance
good discovery channel at an early stage of SuperKEKB
Luminosity (ab-1)

51. Lepton Flavor Violation
Limit to typical SUSY mass mSUSY from 
10 ab−1
possible exclusion region
when |R| = |L| = 1 etc.

52. Correlation btw Observables

53. Correlation btw Observables

54. Correlation btw Observables

55. Correlation btw Observables

56. Dalitz Analysis for 3

60. CKM triangles at Super BSM
3 = 65°
0.5 ab-1
5 ab-1
50 ab-1
New
Physics
3 = 120°
0.5 ab-1
5 ab-1
50 ab-1
Letter of Intent for KEK Super B Factory (KEK-Report )

61. Expected Sensitivities
SuperKEKB
5ab−1
50ab−1
LHCb 2fb−1
CPV (bs)
FCNC
w/ 
CKM
Numbers are not always exactly the same as those shown in this talk.

62. Comparison with LHCb e+e- is advantageous in… LHCb is advantageous in…
CPV in B→fKS, h’KS,…
CPV in B→J/yKS
CPV in B→KSp0g
Most of B decays not
including n or g
B→Knn, tn, D(*)tn
Time dependent
measurements of BS
Inclusive b→smm, see
t→mg
and other LFV
B(S,d)→mm
D0D0 mixing
BC and bottomed baryons
These are complementary to each other !!

63. Why 50 ab−1
Most of the interesting measurements will be limited by unavoidable systematics when we reach 50ab-1.
Obs.
dstat with 50ab-1
dsyst with 50ab-1
Theory err.
sin2f1
0.004
0.014
~0.01 f2
1.2º
a few º f3
1.2º
O(1) º
|Vub| 1%
~1%
~5 %
SfKs
0.023
0.020
AfKs
0.016
0.018
Sh’Ks
0.013
0.020
Ah’Ks
0.009
0.017
DCPV in b→sg
0.003
0.002
0.003