Search for New Physics with Belle and a Super BFactory

1
Search for New Physics with Belle and a Super
B-Factory
Tom Browder (University of Hawaii)
Recent News from KEKB and Belle
Direct CP Violation in a Charged Meson Decay
Observation of b?d penguins B??(?) ?
New Physics Probe CPV in b?s penguin decays
New Physics Probe AFB(B?K ll-)q2
gtgt Super B Factory Plans ltlt
2
The Belle (B Factory) Physics Program

• 1) Measurements of Fundamental SM Parameters
  (complex quark couplings).
• 2) Search for New Physics
• Is there New Physics in loop decays ?
• 3) Unanticipated new particles

Warning Will focus on results relevant to
question 2). Can only cover a small subset of the
rich and broad physics program
3
The KEKB Collider (8 x 3.5 GeV, 22mrad X angle)
SCC RF(HER)
World record
L 1.6 x 1034/cm2/sec
ARES(LER)
4
Normal injection Continuous injection
?1182 pb/day
661/pb/day
5
Belle/KEKB Luminosity Milestone 500 fb-10.5 ab-1
Today some results with 350 fb-1 (386 x 106) B B
pairs
-
1 fb-1/day
Total 512 fb-1
As well as results based on 253 fb-1 (275 x 106 )
B B pairs
-
6
Belle Detector
Aerogel Cherenkov cnt. n1.0151.030
SC solenoid 1.5T
3.5GeV e
CsI(Tl) 16X0
TOF counters
8GeV e-
Tracking dE/dx small cell He/C2H6
m / KL detection 14/15 lyr. RPCFe
Si vtx. det. 4 lyr. DSSD
7
Burnt connectors in the Belle SVD readout system
S1
S4
All the others in FWD also browned One in BWD
(B4) lightly cooked.
8
Possible Explanation

• Tin plating is not chemically stable. Gold is
  better.
• PVC (cables) is evil in a radiation environment.
  Chlorine/hydrochloric acid gas produced by
  radiolysis (or pyrolysis enhanced by radiation).
• Chlorine degrades the tin surface then the
  contact resistance becomes larger.
• When one of the two/three contacts get worse, the
  current funnels towards the other contact.

Approximately 7 days downtime to remove endcaps
and replace SVD connectors. Recovered bad
channels and returned to data-taking.
9
Three Angles (f1,f2,f3) or (ß, a, ?)
B0 ? p- p, B???-
B0-gt? Ks,? KL
B- ?DCP K-
Big Questions Are determinations of angles
consistent with determinations of the sides of
the triangle ? Are angle determinations from loop
and tree decays consistent ?
10
Mixing Induced CP Violation
B0
NB
?f 1 for CP??1
11
Principle of CPV Measurement
Flavor-tag decay (B0 or B0 ?)
J/?
e?
fCP
e?
KS
t0
?z
B - B B B
more Bs
t ? ?z/(cß?)
more Bs
(1-2w)sin2?1
(1-2w)sin2?1
Flavor tag quality r0lt rlt0.5, poor tags, 0.5ltrlt1
good tags.
12
If there is more than one diagram and additional
weak phases, there is the possibility of direct
CPV and a new term with a cos(?m?t) time
dependence.
with q1
13
Measurement of CPV asymmetries, S and A
with q1 depending on the B flavor

14
2005 B0 ? J/y K0 w/386 M BB pairs
_
_
B0 ? J/y KS
B0 ? J/y KL
0
0
Nsig 5264 Purity 98 CP odd
Nsig 4792 Purity 60 CP even
pB (momentum in CM)
15
(No Transcript)
16
2005 B0 ? J/y K0
_
sin2f1 0.652 0.039 (stat) 0.020 (syst) A
0.010 0.026 (stat) 0.036 (syst)
No DCPV
B0 tag
BG subtracted distributions (good tag region)
2003 result sin2f1 0.728 ? 0.061 (152 x 106 BB
pairs)
_
consistent 1.2s

17
Evidence and Observation of Direct CP Violation
in B Decays
DCPV in B???- and B?K- ?,
hep-ex/0502035 (PRL 95, 101801(2005)
hep-ex/0507045
Asymmetries in the Dalitz plot of B ?K ? ?-
hep-ex/0509001
18
Importance of direct CPV in B decays
The final, completely definitive death of any
superweak theory will come from the observation
of direct CP violation in the B system.
Evidence for such direct CP violation would be
given by the difference between the asymmetry
parameters in a decay such as B?? ?- from that
of B?J/? KS. This can be considered the e
experiment for the B system.
Lincoln Wolfenstein, 1999
All CPV in the B system is due to a new
superweak interaction. Expect no CPV in ?B1
transitions.
e.g. J.M. Soares L.Wolfenstein, PRD 27,421
1993.
19
Direct CPV asymmetry in B Decays

• Asymmetry in B decay rates
• The direct CP asymmetry (Adir) can be large
  if two
• amplitudes have comparable sizes, different
  weak phases as well as a strong phase difference.
  This can be arranged in certain B decays using
  the interference of penguin (P) and tree (T)
  decays.

20
Hierarchy of diagrams for B?K p, p p decays
Possibility of tree-penguin interference.
N.B. in B??? the two diagrams are the same order
in ?
21
B?pp- Experimental Controversy
22
Experimental Situation for B?? ?- in 2004
BABAR 227M BB
Belle 152 M BB
with 37232 B0?pp- events
with 46733 B0?pp- events
hep-ex/0501071, to appear in PRL
PRL 93, 021601 (2004)
5.2s CPV, First evidence for DCPV (3.2s)
Also 3.2s discrepancy between Belle and BaBar
23
B0 ?? ?- signal (high LR and low LR)
(LRgt0.86)
(LRlt0.86)
LR (Likelihood Ratio)
r (flavor tag quality)
66643 B?? ?- signal events
Uses high momentum PID from Aerogel and
sophisticated cont. suppression algorithms (LR is
a likelihood ratio based on event shape and
cos(?B) )
24
Bkg subtracted fit projections for B?? ?-
B0 tagged
B0 tagged
DE-Mbc 2D fits to individual time intervals
pp- Yield
pp- ACP
Dt (ps)
25
Summary of Belle B0 ? ? ?- CPV results

• Compelling evidence for direct CP violation in
  B???- with 4.0s significance
• Confirms previous Belle results.
• Isospin analysis for this mode alone gives (95.4
  C.L)

1st error statistical, 2nd systematic

26
Consistency Checks with time-integrated fits
Counting experiment consistent with unbinned
time-dependent fits.
LRgt0.86 0.5ltr1.0
B0 tagged
B0 tagged
pp 10713
pp 6911
Kp 429
Kp 439
cont 381
cont 381
DE (GeV)
Visible indication of direct CP violation.
27
2005 Status of B?? ?-
App
Belle 275M
Spp
BABAR 227M
2.3s difference between Belle and BABAR
- App (Cpp )
Spp
28
DCPV in B0 g Kp-2004 results from BaBar
Belle

• Evidence for DCPV (4.2s)

• Evidence for DCPV (3.9s)

A -0.133 ?0.030 ?0.009
A -0.101 ?0.025 ?0.005
29
2005 Observation of Direct CP violation in
B?K- ?
Belle Update with 386 x 106 B Bbar pairs
(hep-ex/0507045)
Significance 5.0s
One more nail in the Superweak coffin.
30
Interpretation Direct CP violationSU(3)
The results support the expectation from SU(3)
symmetry that
N.G. Deshpande and X.-G. He, PRL 75, 1703 (1995)
M. Gronau and J.L. Rosner, PLB 595, 339 (2004)
HFAG summer 2005
Belle measurement
31
A new approach to DCPV using the Dalitz plot in
B ?K ? ?-
(hep-ex/0509001)
Combined Dalitz plot, signal region
Sample used for B ?K ??- study
contains 224879 B- , 203876 B
32
First fit the Dalitz plot in B ?K ? ? -
Fix the resonant substructure, then allow both
the phase and amplitude to be different for B
and B- decays.
For each resonant amplitude replace aeid with
aeid (1 b eif)
33
Evidence for CP Violation in the Decay B??0 K
(3.9s)
Significance varies from 3.7s to 4.0s depending
on the model for the resonant substructure (add
or remove modes, change nr model, cpv in b?u
background).
34
Evidence for CP Violation in the Decay B ??0 K
Interference between ? and f0 (980) cancels in
the full projection
- helicity hemisphere
helicity hemisphere
35
Comparison of result to predictions and BaBar
Belle Data
(3.9s)
(First evidence for DCPV in a charged meson decay)
Cheng, Gronau, Luo, Rosner, Suprun PRD 69,
034001 (2004)
M. Beneke and M. Neubert Nucl. Phys. B675, 333
(2003)
Four representative scenarios (-27.3, -9.3, 26.6,
31.7)
BaBar Data
(2.4s)
36
A large number of b?s modes are known, where are
the b?d penguins ?
37
First Observation of b?d ?
Yields and significances
38
First Observation of b?d ?
hep-ex/0506079
_
Addresses the same physics issue as Bs- Bs mixing
(future Tevatron RunII LHCB goal).
39
b?d ? consistency checks
Detailed distributions
Toy MC study of experiments that obey the isospin
relation, one finds that the observed BFs are 2s
away from isospin invariance.
Two independent analyses.
40
Evidence for B?K0 K
_
(hadronic b?d s s processes)
hep-ex/0506080
Belle_at_250 fb-1

Measurements of B? K0 K0 CPV at Super B will be
possible.
41
Implications of Belles observation of b?d ?
Together with the evidence of B?K0 K modes, Belle
has demonstrated the existence of a new quark
level transition b?d
SU(3) breaking correction weak annihilation
diagram for BR(B ? ?/w ?)
42
New Physics in b?s penguins ?
43
How New Physics contributes to b?s
Internal Penguin
44
Searching for new physics phases
Example
no KM phase
f1

Vtd
, h, KK-
, h, KK-

B
B

Vtd
f1
_
SM sin2f1 sin2f1 from B?J/y K0 (b?c c
s) unless there are other, non-SM particles in
the loop
eff
45
Belle 2005 update
hep-ex/0507037
46
Compelling Evidence for CP Violation in a b?s
mode
47
gtgtall are systematically below sin(2b) value from
B?J/? K0 modes
Many b?s modes were studied
Belle data hep-ex/0507037
recent theory estimates
Beneke, hep-ph/0505075 Cheng,Chua,Soni,
hep-ph/0506268
sin2f1(penguin)-sin2f1(tree)
48
New Physics ?
Very large effects of order unity, ?S1, are now
ruled out.
Theory corrections are small and opposite in sign
to the exp deviations.
49
Are there New Physics effects of order 0.2 in b?s
CPV ?
Super B Factory level statistics will allow us to
answer this question.
50
Belle Update 2005 (386 x 106 B pairs) Search
for Right-Handed Currents in B?KS?0 ?
Poor tags
Good tags
Use the KS to determine the vertex.
hep-ex/0507059
(MXlt1.8 GeV)
In the SM, S should be close to zero (lt0.10).
SM ? is polarized, the final state almost
flavor-specific.
51
Right-handed currents in b g sg
D.Atwood, M.Gronau, A.Soni (1997) D.Atwood,
T.Gershon, M.Hazumi A.Soni (2004)

• tCPV in B0 g KS p0g
• mheavy/mb enhancement for right-handed currents
  in many new physics models
• LRSM, SUSY, Randall-Sundrum (warped extra
  dimension) model
• LRSM SU(2)L?SU(2)R?U(1)
• Right-handed amplitude ? ?mt/mb ? is WL -WR
  mixing parameter
• for present exp. bounds (? lt 0.003, WR mass gt
  1.4TeV) S(Ksp0g) 0.5 is allowed.
• Here an asymmetry does not require a new CPV
  phase

52
New Physics in AFB (B?K ll-)?
b?s ?
Note in b?s ll- different operators,
contributions from virtual ? , W, Z and
internal t quark. (and New Physics particles).
53

Forward event
Backward event
? and Z contributions in B?K l l interfere
and give rise to forward-backward asymmetries
c.f. ee- ?? ?-
Unbinned fit to the variables q2 (di-lepton
invariant mass) and cos(?) for B?K l l data
54
A Scary Slide about New Physics
b?s ?
55
2005 Sample used for AFB(B?Kll)(q2)
hep-ex/0508009
Treat q2, cos(?) dependence of bkgs.
Sample for B?K l l events 11313
B?K l l control sample 9612
Consistent with flat
56
Constraints on Wilson coefficients from AFB(B?K
l l)(q2)
Projections of the full fit to q2, cos(?)
Integrated FB asymmetries
control sample
Observe integrated AFB and as a result can rule
out some radical New Physics Models with
incorrect signs/magnitudes of C9 and C10
57
Results of the unbinned fit to q2 and cos(?)
distributions for ratios of Wilson coefficients.
SM
A10/A7
Best fit
A9/A7
A7 constrained from b?s ? to be close to SM
Ref hep-ex/0508009
at 95 C.L.
58
AFB(B?K l l-)q2 at Super B Factory

• Assume 1 year of running at 5x1035/nb/sec
• ? 5/ab integrated luminosity, 10 billion B mesons
• DA9/A911, DA10/A1013
• A7 fixed to SM value

AFB (Kll) with 5/ab
Donut B(B?Xs l l) with140/fb 100/fb
C10NP
Belle Toy MC with 5/ab
C9NP
Determine location of the zero crossing precisely
with 50 ab-1
59
Fundamental Questions in Flavor Physics
Are there New Physics Phases and New sources of
CP Violation Beyond the SM ?
Experiments b?s CPV, compare CPV angles from
tree and loops
Are there new operators with quarks enhanced by
New Physics ?
Experiments AFB(B?Kl l), B?K ? rates and
asymmetries
Are there right-handed currents ?
Experiments b?s ? CPV, B?V V triple-product
asymmetries
Are there new flavor changing neutral currents ?
Experiments b?s ??bar, D-Dbar mixingCPVrare,
t???
These questions can only be answered at a Super B
Factory.
60
-
hep-ex/0507034
Search for B?t? and B?K?? with 250 fb-1 of
Belle data
BF(B?t?)lt1.8 x 10-4
(Expected level 0.9 x 10-4 )
-
BF(B?K ? ?)lt3.6 x 10-4
(SM expected 3.8 x 10-6)
61
B tagging provides a B-meson beam
MC extrapolation to 50 ab-1
5s
Observation of B g K n n
(compare to KL g p0nn)
Extra EM calorimeter energy
Super B LoI Fig.4.18
62
Super B Factory Motivation

• Physics beyond the Standard Model (SM) must
  exist.
• LHC may find TeV-scale New Physics
• If the LHC finds New Physics at the TeV scale,
• its flavor structure must be examined
  experimentally. A super B factory is the best
  tool for this purpose.
• If the LHC finds nothing but a SM-like Higgs,
• searching for deviations from the SM in flavor
  physics will be one of the best ways find new
  physics. (remember history)

63
New physics effects in B physics
Different New Physics scenarios and their effects
in B decays.
G.Hiller
64
Comparison of Super-B and LHCb

• Clean environment ? measurements that no other
  experiment can perform. Examples CPV in B g fK0,
  B g hK0 for new phases, B g KSp0g for
  right-handed currents.
• B-meson beam technique ? access to new decay
  modes. Example discover B g
  Knn.

• Measure new types of asymmetries. Example
  forward-backward asymmetry in b g smm, see
• Rich, broad physics program including B, t and
  charm physics. Examples searches
  for t g mg and D-D mixing with unprecedented
  sensitivity.
• No other experiment can compete for New Physics
  reach in the quark sector.

65
Super B Factory at KEK
Interaction Region Crab crossing q30mrad. by
3mm New QCS
New Beam pipe
More RF power
Damping ring
Linac upgrade
L 4?1035/cm2 /sec
66
Crab crossing in the near future
?Crab crossing may increase the beam-beam
parameter up to 0.19 !
(Strong-weak simulation)
K. Ohmi
Head-on (crab)
(Strong-strong simulation)
crossing angle 22 mrad
?Superconducting crab cavities are now being
tested, will be installed in KEKB around March
2006.
K. Hosoyama, et al
67
Testing and Preparation of KEKB Crab Cavity
New HPR Facility at KEK
Transition Flange
Nozzle
Transition Flange
68
Requirements for the Super B detector
Critical Issues at L 4 x 1035/cm2/sec
4 Higher background ( ?20) 4 Higher event rate
( ?10) 4 Require special features

• radiation damage and occupancy
• fake hits and pile-up noise in the EM

- higher rate trigger, DAQ and computing

• low p m identification f smm recon. eff.
• hermeticity f n reconstruction

69
Belle Upgrade for Super-B
70
KEKB Collider Upgrade Scenario
Lpeak 1.6?1034cm-2s-1 Ltot 469fb-1 (Nov.30,
2004)
1010 BB/year !! similar number of tt-
world records !
Major upgrade of KEKB Belle detector (gt1yr
shutdown)
SuperKEKB
crab cavities
Lpeak (cm-2s-1) Lint
5x1034 1 ab-1
1.6x1034 469 fb-1
5x1035 10 ab-1
71
CPV in b g s and diagnosis of new physics
Expected precision at 5ab-1
Many other examples of using correlations to
distinguish new physics scenarios have been
examined.
T.Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanaka
(2002, 2004) SuperKEKB LoI
72
A Broad Unbiased Approach to New Physics
n experiments, gm-2, mgeg, etc.
LHC, ILC
n mass and mixing, CPV, and LFV
Mass spectrum, interactions
Energy frontier
Lepton sector
New physics
Quark sector
Flavor mixing, CP phases

• LFV,
• t CPV

Super B factory, LHCb, K experiments
73
Yamauchis Schedule for Super B
A Super B proposal was submitted to MEXT in
August 2005.
KEKB/Belle project receives a grade of S(i.e. A)
in gov. review
A search for a new KEK laboratory director is
underway.
J-PARC 1 construction
ILC construction
Construct. fund
T2K
SuperKEKB const.
Operation fund
Crab cavity
KEKB machine
SuperKEKB
KEKB
gt1000fb-1
Major upgrade
Minor upgrade
Belle
2004
05
06
07
08
09
10
11
12
Calendar year
74
Yamauchis budget for Super B
75
Backup Slides
76
2005 Status of the CPV Angle Measurements
Also consistent with constraints from measmts of
lengths of sides.
?0.3210.027
?0.1930.57
?0.3420.022
?0.2160.036
77
CKM Unitarity Triangle (in)consistency
Two cases at
50 ab-1
Super B Factory
Something new in?
Right f3 (tree) measurement are inconsistent
with loops.
78
History of sin2f1 measurements of B0 ? J/? K0 at
Belle

• 152 x 106 B meson pairs
• sin2f1 0.693 0.065 (stat)
• 386 x 106 B meson pairs
• sin2f1 0.652 0.039 (stat) 0.020 (syst)

Consistent at the 0.6s level
79
Hints for New Physics ?
ACP(B?Kp) is equal between B and B0.
CPV(tree)CPV(penguin) if only SM is assumed.
fL (B?VV) 1 in SM
tree
penguin
B0
B
tree
penguin
These hint at new physics contributing to bgs
penguin processes.
80
Search for flavor-violating t decay

• SUSY Seesaw
• Flavor violation by n-Yukawa coupling.
• Large LFV

Br(t?mg)O(10-79)
Expected sensitivity at Super KEKB
Present Belle
Super-KEKB
t?lg
t?lp/h/h
t?3l
t?l Ks
t?Bg/p
Gaugino mass 200GeV
81
Comparison of Super B Factory and LHCb
sensitivities
Modes with neutrals or multiple neutrinos are not
possible at LHCb. LHCb cannot trigger on B?f K0
82
Distinguish different NP models
One example from the Super B LoI
Different SUSY breaking scenarios can be
distinguished.
Time-dependent CPV for B0? K0Ksp0g
(SKg0 in SM)
83
Identification of SUSY breaking scenario
Pattern of deviations from the Standard Model
Observ- ables
SUSY models
Large, sizable, - small
84
Representative New Physics Scenarios considered
for the Super B LOI.
85
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86
Dalitz plot for the signal in data
D0 f-
M(KSp-)
_
D0 f-
M(KSp)
87
Reconstruction of B0 ? DKSpp-h0
_
D0 p0
D0 w
D0 h
D0 p0, h
Nsig 157 24 purity 59
Nsig 67 10 purity 86
Nsig 58 13 purity 60
Nsig 27 11 purity 52 D0 ? D0 p0
D ? D0 pi0 Dpi0 22 - 9 Deta 5- 6
TOTAL Nsig 309 31 purity 63
88
New Method B0 ? DKSpp-h0Direct measurement
of f1
_
hh0 CP eigenvalue, l orbital angler momentum
89
Dalitz PDF is calibrated with data
_
D ? D0(KSpp-) pslow in real data Charge of
slow p distinguish D0 or D0
_
Modeled with 18 resonances one
non-resonant amplitude
Phys. Rev. D 70, 02003 (2004) f3 measurement with
Dalitz
90
Super KEKB parameters
91
Vacuum componentsBellows chamber with comb type
RF-shield
?High thermal strength ?Low impedance ?No sliding
contact on the surface facing the beam
Comb-type bellows were installed in the LER
(2004).
92
Constraints on the Unitarity Triangle
?
f170o
sin2f1
?
f120o
f1
2-fold ambiguity 2f1 ? p-2f1
93
B0 ? DKSpp-h0New Method for Direct
measurement of f1
_
q/p1, arg(q/p)2f1
D0 ? KSpp-
94
Time-Dependent Dalitz fit results
Belle preliminary
-30o lt f1 lt 62o (95 C.L.)
95
Implications of Time-dependent Dalitz analysis
Consistent with B0?J/yK results cos2f1
0.87 0.75, hep-ex/0504046
?


f170o
Disfavored gt2s
sin2f1
?
(_)
f120o
f1
2-fold ambiguity resolved !
96
Method for f3 (?) measurement
Simple mixing CPV ? f3 (with Bd )

Tree
Tree
fCOM
_
fCOM
O(l3)
O(l3)
Interference of b?c and b?u diagrams
97
New method from Belle Dalitz
3) fCOM D0 ? KSpp-
B
obtain from tagged D0 (D? D0p) sample
A2 A1
B-
r
CPV Asymmetry in Dalitz dist.
mm(Ksp), m-m(Ksp-)
98
Signals for B?D K, D?KS ??-
hep-ex/0504013
hep-ex/0411049
D0K
D0K
D0K
D0p0
58 signal
36 signal
209 signals
99
B?D K, D?KS??- Dalitz Analyses
100
Another class of modes for f3 B?DCP K and
B?DCP K
Fairly subtle treatment of bkgs. required.
Measure BFs and CP asymmetries Kent, Trabelsi
and TEB. Phys Rev D paper in preparation.
101
f3 Results (Belle and BaBar)
hep-ex/0411049,0504013
f3 63 ? deg.
15 13
hep-ex/0504039
(Non-trivial constraint)
102
CPV in B0? rr?
Similar to B?pp?, but in principle more
complicated
B ? VV not a single CP eigenstate r ? pp0
wide resonance, two ?0s in the final state.
Three miracles
fL 100 ? CP 1
B??(??)NR and int. small
B(r0r0) ltlt B(rr?), B(rr0) lt 1.1
30 ? 6 (26 ? 6 ) x 10-6 (HFAG Winter05)
2q
A-/ 2
small Penguin pollution (q )
A00
A0
103
B0? rr? signal
continuum
b ? c
signal
b ? u
B 24.4 ?2.2 ? x 10-6
Mpp
Helicity
3.8 4.1
continuum
continuum
signal
r pp
fL 0.951 ? ?
0.029 0.031
0.033 0.039
Belle-CONF-0545
104
2005 Belle Results on CPV in B???-
Preliminary (274 ? 106 BB pairs)
q1
q-1
Results
Low quality tag
High quality tag
No CPV? f2 is near 900
105
Belle Constraints on ?2 (a)
B??? only
B??? hep-ex/0502035 ?? combined
at 90 CL
at 90 CL
106
Belles measurement of ACP(B??0 ?0 )
hep-ex/0408101
published in PRL
275M BBbar pairs
107
KM ansatz CPV is due to a complex phase in the
quark mixing matrix
108
sin2?1 from B?fCP B?B?fCP interf.
Sanda, Bigi Carter
J/y
Vcb
B0

KS
?V2
?
td
J/y
V
Vtb
td
B0
B0
KS
V
Vtb
td
109
Crab Cavity in He Vessel (3D)
Support Rod
Jacket Type Main He vessel
SUS316L
Jacket Type Sub He vessel
Tuning Rod
Input Coupler
Notch Filter
Crab Cavity Cell
RF Absorber
Coaxial Coupler (Nb)
Extract TM010, TE111 Mode Frequency Tuning
Stub Support