Belle Status & Plans
Y.Sakai (KEK)

21-Feb-2005

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1Physics at B-factory
B decays*
Vud Vubφ (α)

Quark level
Electro-weak

2Vtd Vtb*

φ3(γ)

φ1(β)

*
Vcd Vcb

Hadrons
Final state

CKM/CPV

QCD/Lattice
New Resonancesb-quark: Heavy → variety of decay modes
Comparison with SM → New Physics !
(also excellent τ/charm & γγ factory)
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Integrated Luminosity
Data used in analysis_~ doubled from 152M → 275M BB

KEKB

this year

last year!
last year

PEP-II_122M → 227M BB

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~Doubled Data size
Fruitful Physics Results !
60 contributed papers
24 talks (ICHEP04)
Highlights/Demonstration• B → hh_ : DCPV
• b → sqq TCPV• B → π+π− TCPV (New)• New “new resonances”
ICHEP04 / FPCP04
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Direct CPV: B → Κπ∗
Vus/db

B0dd_ _s/dWuVubudΚ/π+π-b

B 0ddVtbWt∗

Vts/d s/dg+Κ/πuudπ-TreePenguin• Simplest charmless rare decay modes• Tree - Penguin interference → Direct CP Violation_ _Key prediction ofKobayashi-Maskawa model

Observation in B

Γ(B→ f ) − Γ(B→ f )_ _ACP =Γ(B→ f ) + Γ(B→ f )Strong support of KM
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ACP(B0 → K+π−)152M BBACP = -0.088± 0.035 ± 0.018~2.2σ [hep-ex/0407025]
275M BB_
B0→ K−π+

B0→ K+π−Signal: 2139 ±53
ACP = -0.101± 0.025 ± 0.005
3.9σ significance [PRL93, 190802](2nd Evidence of DCPV in Belle: 1st B → π+π− TCPV)KEKB Accelerator Rview

6ACP(B0 → K+π−)275M BB_B0→ K−π+

B0→ K+π−Signal: 2139 ±53
ACP = -0.101± 0.025 ± 0.005
3.9σ significance
227M BBACP = !0.133 ± 0.030 ± 0.009[PRL93, 131801]

Average of Belle and BaBar

ACP = !0.114 ± 0.020 > 5σ !
First established Direct CPV in B decays !
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Observation of B0 → π0π0Key mode for φ2(α) in B  ππ
CPV isospin analysis
152M BB

Evidence !

Signal: 26 ± 9 (3.4σ)[PRL91, 261801]

275M BBObservation !

Signal: 82 ± 16 (6.0σ)
0.22-6B = (2.32 ±0.44±)x100.48 0.18
Large Br established6.0σ[hep-ex/0408101, to PRL]KEKB Accelerator Rview

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ACP of B0 → π0π0275M BB

uses same Flavor-tagging as TCPV analysis

ACP = 0.44 ± 0.51 ± 0.170.16
1st measurement !

used in φ2(α) in B  ππ
CPV isospin analysis[hep-ex/0408101, to PRL]KEKB Accelerator Rview

9Time Dependent CPV
Mixing Induced CPVB0mixing
q/p

ACP ≡AB0ｆｃ− ｐA

Γ(B0 → f ) − Γ(B0 → f )dCPdCPΓ(B0 → f ) + Γ(B0 → f )dCP
dCP2ImλS = 1+ |λ|2ｆｃ= B0ｐ

B0SandaBigi
Carter= S sin(ΔmΔt) + A cos (ΔmΔt)
Mixing induced CPV|λ|2 −1
A = |λ|2 +1

λ=Direct CPVq Ap A

CPV in B → J/ψKs etc. discovered in 2001 !
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Results for sin2φ1

B → J/ψKs etc.

Good SM reference

LP2003

ICHEP
2004

sin2φ1 (2003 World Av.)

sin2φ1 (2004 World Av.)
= 0.726±0.037 (~5%)= 0.736±0.049

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New physics Search : b → sqq_B0bdts φs+sKd SB0→ φKsbdXs φss Kd S68 ev“sin2φ1”= ξf S
= −0.96 ± 0.51
Belle @LP03

SM: +0.73

3.5σ deviationfrom the SM !
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12B0 → φ K0(Ks → π0π0)152M BB

Nsig(φKS)=68(64%)[PRL91, 261602]

includes Ks → π0π0(Nsig=13 ±5)

φKS 275M BBφKLNsig=139 ±14purity 0.63Prme liraniy[hep-ex/0409049]

Nsig= 36 ±15
purity 0.17

pB*

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B0 → φ K0 : CPV Results
152M BB[PRL91, 261602]

B0→ φKs

SM: +0.73

68 ev Good tags

“sin2φ1”
S = −0.96 ±0.50 ±0.11
A = −0.15 ±0.29 ±0.07

275M BB[hep-ex/0409049]

SMfit

φKS + φKLGood tags

ler
P

imyr
ain

“sin2φ1”
S (φK0) = +0.06 ± 0.33 ± 0.09
A (φK0) = +0.08 ± 0.22 ± 0.09
~2σ away from SM

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B0→η’KS
152M BBη’KS[PRL91, 261602]

Nsig=512 ±27
purity 0.61

SM
fit

Good tags+0.18

S = + 0.51 ± 0.26 ± 0.05! 0.00
A = ! 0.17 ± 0.16 ± 0.04

Raw Asymmetry

Nsig=244(58%)“sin2φ1”high statistics modes
275M BBη’→ ργ,
ηπ+π−(η→ γγ,π + π− π 0 )

SM
fit
lier

Good tagsmraniy

P [hep-ex/0409049](~0.5σ @SM)“sin2φ1”
S = +0.65 ±0.18 ±0.04
A = −0.19 ±0.11 ±0.05
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B0→ωKS & f0(980)KSRaw Asymmetry

Nsig=31 ±7New modes

purity 0.56
PlireGood tags(~0σ @SM)“sin2φ1”
S = +0.75 ±0.64 ± 0.130.16
A = +0.26 ±0.48 ±0.15

mrani

Raw AsymmetryωKSf0(980)KS

275M BB

Nsig=94 ±14
purity 0.53

[hep-ex/0409049]yS = −0.73
fitGood tags(~2.9σ @SM)

−S = −0.47 ±0.41 ±0.08
A = −0.39 ±0.27 ±0.08
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B0 → Ksπ0
Vertexing Ks trackby Ks only

Ksπ0π+ π−

Nsig=168 ±18
purity 0.55

B vertex
IP profileγ(+low purity: Nsig=83(0.17))

P r e lim in ary(~0.7σ @SM)“sin2φ1” S = +0.30 ±0.59 ±0.11
A = −0.12 ±0.20 ±0.07
275M BBRaw Asymmetryγ
Validated by J/ψ Ks (use Ks only)

S = 0.73
fit

Good tags[hepex/0409049]
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“sin2φ1” from bs penguins
0.726 ± 0.037
0.736 ± 0.049

3 modes~3.5σ0.24 ± 0.15~3.1σ from s-penguin to sin2φ1 (cc)7 modes0.41 ± 0.07~3.8σ from s-penguin to sin2φ1 (cc)
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B0→ π+π− CPV
Feldman-Cousins Analysis

Observation of CP violation(5.2σ)
Evidence for direct CP violation≥3.2σ

Aππfor Aππ=0 and any Sππ152M BBSππ

Winter 2004
[PRL91, 021601]
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History of Aππ and Sππ
B0→ π+π−TCPV

Belle

Difference
Winter04: ~2.2σ
Summer05: ~3.1σ_227MBB
Summer05

BaBar[hepex/0501071, to PRL]?

presented at Aspen
18-Feb-2005 New
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B0  π+π− signals
275M BB
152M BB

0.86 < LRHigh qualityP(372 ± 32) π+π−signals[PRL91, 021601]

liermraniy(666 ± 43) π+π−signals[hepex/0502035]
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B0→ π+π− CPV Results
275M BB
152M BBP

good tag Δt (ps)Aππ = +0.58 ±0.15±0.07
Sππ = −1.00 ±0.21±0.07

liremraniy

good tag Δt (ps)Aππ = +0.56 ±0.12±0.06
Sππ = −0.67 ±0.16±0.06
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22AππNew Exp. Summary
Belle 275MPliremraniy~2.3σ difference betweenBelle and BABAR

BABAR 227M

Sππ

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Significance

275M BBAππ

Large CP Violation,(A,S)=(0,0)
1-C.L.=5.62x10-8, 5.4σ
(A,S)=(0,−0.62)
1-C.L.=5.13x10-5, 4.0σ
Prelimraniyboth statistical and systematic errors
are taken into account.

Large Direct CPV
confirm previous
Belle results

Sππ[hepex/0502035]

Feldman-Cousins Analysis
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Check: Time-Integ. CPVA!! = +0.52 ± 0.14

Pliremraniyconsistent with time-dependent fit

LR>0.86 & 0.5<r≤1.0tag-side: B0tag-side: B0
ππ: 107±13
Kπ: 42 9cont: 38 1ππ: 69 11Kπ: 43 9
cont: 38 1

Direct CP Violation is evident!
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Isospin Analysis: φ2 constraint
M. Gronau and D. London, PRL 65, 3381 (1990)
2S## = 1 $ A##sin( 2"2 + 2! )Belle result

B → ππ Br & ACP
HFAG 2004 Summer
World Averages

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φ2 constraint

1−C.L.

275M BBPreliminusing HFAG
summer 2004ary

φ2 (degrees)Fit method:
J. Charles et al.,hep-ph/0406184

95.4% confidence interval
0o < !2 < 19o and 71o < !2 < 180o[hepex/0502035]

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New Resonances

Factory Bonuses !

Discovery of X(3872) LP03
ψ(2S)

[PRL 91, 262001(2003)]

Narrow peak in
J/ψπ+π− mass !

Mx = 3872.0 ± 0.6(stat) ± 0.5(sys) MeV/c2, Γx < 2.3 MeV/c2
Still mystery: what is it ?

confirmed by CDF, D0, BaBar
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X(3872): New decay mode
275M BBωB → J/ψ (π+π−π0)Κ
X(3872)

2nd decay mode

M(J/ψ π+π−π0)12.4 ± 4.2 evts
signif. ≈ 4σPliremraniyΓ(X→ π+π− π0J/ψ)/Γ(X→π+π− J/ψ)= 1.1 ±0.4± 0.3
BK X(3872)[hepex/0408116’]

M(π+π−π0)~ DD* bound-state model[Swanson, PLB 588,189 (2004)]
KEKB Accelerator Rview

29ωJ/ψ low-mass Enhancement
275M BB

B → J/ψ (π+π−π0)Κ

M2(J/ψ ω)

cut here ( >1.62 GeV2)[hepex/0408126, to PRL]

Y(3940)M≈3941±11 MeVΓ≈ 91±24 MeV

Significance>8σBK** J/ψKω
M2(Kω)

unlikely normal (cc) state
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X(3940): New (cc) state ?
e+e- → J/ψ (cc)res

287 fb-1
X(3872)X(3940)• No signal of X(3872)• Significant peak at
M=3.940±0.011 GeV/c2
N=148±33 (4.5σ)
width: narrow<~ resolution(= 32 MeV)
• Hint of X(3940) → DD*

ηc

χco

[e+e- →γ* → J/ψ J/ψ : forbidden by C-symmetry]

η’cPrelimirnay[hepex/0412042]

KEKB Accelerator Rview31Σc(2800): New c-Baryon

281 fb-1[hepex/0412069, to PRL]

Yield
1540

Yield
2240
Charge=0

Charge=1

Yield2810
Charge=2Σc0/+/++ → Λc+π−/0/+
JP=1/2+
L=0

Isospin triplet

JP=3/2− width ~70 MeV
L ≠ 0 > 5σ significance(candidate)

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Plan
L~1.5x1033/cm2s~1 fb-1/day

KEKB isimproving~460 fb-1

by Summer 2005

1 ab-1in a few years

Now ~360 fb-1

More New& improvedresults
SuperKEKB/Belle
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Plan
KEKB isimproving~460 fb-1by Summer 2005

1 ab-1in a few years

More New& improvedresults
SuperKEKB/Belle
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Summary_2003 summer → 2004 summer: 152M → 275M BB
Excellent KEKB performance: Data size ~ doubled !
Significant New/improved results !
• DCPV established ! ACP(B → K+π−), Aππ _• Stronger evidence: “sin2φ1” ≠ SM in b → sqq decays• More New resonance observed !
:We (Belle) are looking forward to having
higher/more luminosity and New excitements !
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