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Superb prospects:Superb prospects:Belle & KEKB upgradesBelle & KEKB upgrades

Kay KinoshitaUniversity of Cincinnati

Belle Collaboration

July 26-31, 2009

motivationmotivationplanplanstatusstatus

(CP Violation (CP Violation III)III)

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Experiments (-2009)• CP asymmetry manifested in diverse processes in B decay -> many measurements, (over)constrain CKM

B-factories (1999-2009)B-factories (1999-2009)

Primary goal: establish unitarity & complex phase of CKM matrix

Kobayashi & Maskawa (1973)•  proposed 3rd generation of particles• Explain CP violation in K, predict for B

found consistent with unitarity

2008 Nobel

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B-factories (1999-2009)B-factories (1999-2009)

• … + many other successes

+ more measurements, on+ more measurements, onB, charm, tau, 2-photon, B, charm, tau, 2-photon, ϒϒ(4S), (4S), ϒϒ(10860), B(10860), Bss, , ϒϒ(3S), (3S), ϒϒ(1S), ... (1S), ...

Addressing Addressing CP, CKM, QCD, HQ spectroscopy, LFV, NP, Dark CP, CKM, QCD, HQ spectroscopy, LFV, NP, Dark Matter, ...Matter, ...

HeadlinersHeadliners• • new charmonia, charmonium-like states, ISR, Dnew charmonia, charmonium-like states, ISR, DsJsJ, , many B decaysmany B decays• • DD00 mixing mixing• • limits on/hints of New Physics limits on/hints of New Physics

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B pairs world sampleB pairs world sample

KEKB/Belle

KEKB + PEP-II

~946/fb (6/09)~946/fb (6/09)

~553/fb~553/fb

design lu

minosity of K

EKB

L max = 2.1 x 1034/cm2 /sec

(design=1.0) PEP-II/BaBar

~ 1.5 billion BB pairs

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Why collect more?Why collect more?

With 1.5G Bpairs (+similar #’s of c, tau) at Belle+Babarmany best measurements:testing CKM unitarity, exploring SM-suppressed/forbidden regions

φ1, φ2, φ3 β,α,γ

ρ0ρ0(φ2), Dalitz (φ3),

b->dγ

SM-suppressed B & D processes

Lepton

universalityB-> τν,

B->D(*) τν

LFV τ->µγ

many of these measurements/limits are statistically limited

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furthermore ...

to account for to account for baryon baryon

asymmetryasymmetryof universe... of universe...

NEED other NEED other source(s) of CP source(s) of CP violation violation

Why collect more?Why collect more?

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Why collect more?Why collect more?

complementary to LHC: γ, KL detection; hermeticity -> neutrinos

With x102 luminosity,

in a facility designed for CP studies,

a significant new window

b->s penguin(φ1)

b->sγ, b->dγ, B-> sl+l-

RH currents in B->{s}γ

CP in D mixing

Lepton universality

SM-forbidden lepton

processes

ρ0ρ0(φ2), Dalitz (φ3),

b->dγ Higgs inB-> τν,

B->D(*) τν

LFV τ->µγ

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VVtbtb*2*2VVtdtd

22VVcbcbVVcscs**mixing+tree

SM: “golden” vs “other” sin2SM: “golden” vs “other” sin2φφ1 1 (sin2(sin2ββ))

VVcbcb**VVcscs

tree (real Vij)

“golden” B -> J/ψ Ks

=> relative phase = 2φ1, CP asymmetry ~ sin 2φ1

identical hadronic processes -> same |Amplitude|identical hadronic processes -> same |Amplitude|

VVcbcb**VVcscs real => zero phase difference

well-measured ratewell-measured rate

mixing

phase = arg(VVtbtb*2*2VVtdtd

22)=2φ1

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““other” sin2other” sin2φφ11

b -> sss̅: identical reasoning

“New Physics” w complex phase φnew ---> CP asymmetry ≠ sin (2φ1)

VVtbtb*2*2VVtdtd

22VVtbtbVVtsts**mixing+penguinVVtbtb

**VVtstspenguin (real Vij)

VVtbtb**VVtsts real => zero phase difference

=> relative phase = 2φ1, CP asymmetry ~ sin 2φ1

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Standard Model: “other” sin2Standard Model: “other” sin2φφ11

caveat: (small) theory correction -> mostly >0

VVtbtb**VVtsts

penguin (real Vij)

b -> sss̅: identical reasoning

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Heavy Flavor Averaging GroupAverage “sin2Average “sin2φφ11” from ” from b->sb->s penguins penguins

Naïve World Average sin2φ1(b->sqq̅)= 0.62 0.04

Compare to ccs̅:sin2φ1(b->cc̅s) = 0.672

0.024CL = 0.19 (1.3σ)

difference is < 0

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““sin2sin2φφ11” sensitivity to New Physics” sensitivity to New Physics

Already exploring “New” region:to improve sensitivity,need better• statistics• systematics• theory corrections

(Luminosity Projections)

✪Babar: PRD79, 052003(2009)

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Right-handed currentsRight-handed currents

Atwood, Gronau, Soni (PRL 79, 185 (1997))Atwood, Gershon, Hazumi, Soni (PRD 71, 076003 (2005))

large asymmetry <->

right-handed current

Currently:consistent with no

RH currents(but need more data

for good sensitivity...)

• in SM • B0→Xs

CPγ is • ~flavor-specific (γ polarization)• -> low CP-asymmetry, O(3%)

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Right-handed currentsRight-handed currents

CP asymmetry in B → KSπ0γ

precision

integrated luminosity

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BB++->->ττ++ννττ : constraints on charged Higgs : constraints on charged Higgs

{WS Hou, PRD 48, 2342 (1993)}

(extrapolation) 50 ab-1

allowed

allowed

(Belle) 0.65 ab–1

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Lepton universality: BLepton universality: B

SM:B(B->) = 1.6x10-4

B(B-> ) = 7.1x10-7

B(B-> e) = 1.7x10-11

B-> B->

deviations from SMsensitive to NP

Luminosity (ab-1)

Significance

expect observation with ~4 ab-1

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10

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Lepton universality: B Lepton universality: B D D(*)(*)

cb

H/W

tan cotb cm mβ β+

tanm β

( )

( )

B D vB

B D v

Γ →=

Γ →

B(B0->D*-) = (2.0±0.4±0.4)%[PRL 99, 191807 (2007)]

– Ratio (/) is sensitive to charged Higgs (similar to B)

M.Tanaka

• universality via semileptonic decays

BX decays probe NP in different ways:•B: H-b-u vertex•BD: H-b-c vertex

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D mixing/CP violationD mixing/CP violation

For 75 ab–1

x=0.8y=0.8

~4σ significance on 1-|q/p|

|q/p|=0.9

>4σ significance on x>5σ significance on y

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of B’s

=> what we need is

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Super KEKB Luminosity projectionSuper KEKB Luminosity projection

3 year shutdown for upgrade

~ 2016 10ab-1

L~8x1035 cm-2s-1

50ab-1 by ~2020x50 present

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KEKB luminosity upgrade strategyKEKB luminosity upgrade strategy

“nano-beam” scheme (proposed by P. Raimondi for Italian Super B factory)

1.8A(LER)/1.45(HER) 3.8A/2.2A

6.5(LER)/5.9(HER)

0.26/0.26

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Detector: Background projectionsDetector: Background projections

IssuesRadiation damageOccupancyFake hits, pile-upEvent rate

Belle detectorSuperKEKB

(hi-current design)normalized to current rates

Design upgrade to tolerateDesign upgrade to tolerate~20X at full luminosity~20X at full luminosity

Year

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Detector: Belle IIDetector: Belle II

Upgrade of Belle to operate w 20X background, 50X event rate baseline: current performance + improved PID

Design Study ReportarXiv: 0810.4084

Baseline design – not finalSatisfies minimum requirementsMany alternatives under study: Design to be finalized in 2009

Physics studiesDetector simulations based on Geant 3, fast simulator, Geant 4

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Belle II baselineBelle II baseline

New dead-time-free pipelined readout and

high speed computing systems

Faster calorimeter with waveform sampling and pure CsI (endcap)

New particle identifier with precise Cherenkov device:

(i)TOP or fDIRC.Endcap: Aerogel RICH

Si vertex detector withhigh background tolerance

(+2 layers, pixels)

Background tolerant super small celltracking detector

KL/ detectionwith scintillator

and next generationphoton sensors

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Placement of KEKB upgrade on Roadmap (Jan. 2008)-> official priority of KEK

• 3-year upgrade: 2010–2 • L ∼ 8 × 1035 cm−2s−1

• Funding: 3.2 x 109 ¥ (~$32M) for FY 2009request for construction (2010-): $350M

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Belle II CollaborationBelle II Collaboration

• New international collaboration (not extension of present Belle)

http://superb.kek.jp

Belle

• First meeting December 2008• next meeting Nov. 18-9, 2009• Spokesperson: P. Krizan (Ljubljana)

US institutionsUniversity of Cincinnati

University of HawaiiVirginia TechWayne State

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SummarySummary

• B-factories 1999-2009, >1.4x109 B pairs: firmly established CKM as main source of CP asymmetry

at low energyplaced multiple constraints on CKM unitarity

high precision -> probe for New Physicsrare processes as windows to New Physics

incl. D mixing, tau decays

•~102X luminosity will probe >1 TeV mass scaleprecision CKM, CP, lepton universality, LFV(complementary to LHC)

• KEKB upgrade for L=8 x 1035 included in KEKB Roadmap•SuperKEKB/Belle II plans well underway

new international collaboration forming