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Recent results from Belle and Recent results from Belle and Status of Status of SuperKEKB/Belle IISuperKEKB/Belle II

Chengping ShenUniv. of Hawaii, Belle collaboration

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OutliOutlinene

David Atwood, Isard Dunietz, and Amarjit Soni [PRL 78, 3257 (1997), PRD 63, 036005 (2001)]

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First evidence of ADS B → DK

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ɸɸ33/ɣ/ɣ is the least well measured of the unitarity angles. is the least well measured of the unitarity angles.

One of methods uses D→KOne of methods uses D→K++ππ--, ADS(, ADS(David Atwood, Isard Dunietz, and Am

arjit Soni ) mode [) mode [PRL 78, 3257 (1997), , PRD 63, 036005 (2001)], ], for which the effect of CP violation can be enhanced by the comparablfor which the effect of CP violation can be enhanced by the comparabl

e magnitudes of interfering amplitudes.e magnitudes of interfering amplitudes.

CKM and color suppressed

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9RDK measurement is an important

Input value for the ɸ3 angle determination

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Bs →J/Ψ(η, η', f0), Ds(*)+Ds

(*)-

(CP-eigenstates)

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17Difference in widths between two Bs-Bs mass eigenstates (time-independent)

18PRL105,201802(2010) 23.6fb-1

19PRL105,201802(2010) 23.6fb-1

20PRL105,201802(2010) 23.6fb-1

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(indirect measurement)

direct measurements

CDF and D0 measured Delta Gamma using the time distributions of Bs decays. This has no model dependence.

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X(3915)&& X(4350)in J/and J/ (first o

bserved at Belle)

X

X: JPC=0++,0-+,2++,2-+,…

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New peak in J/

X

M: 3914 3 2 MeV,

: 23 10 +2 MeV, Nres = 55 14 +2 MeV

Signif. = 7.7, Background only fit

ee++ee-- undetected undetected pptt balance required balance required

XX(39(391515))→J/→J/ψωψω in in γγγγ fusion? fusion?

PRL 104, 092001 (2010)

-8

-14

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Could it be the Z(3930) ( ) ?

M: 3914 3 2 MeV,

: 23 10 +2 MeV,

Nres = 55 14 +2 evts

M = 3929±5±2 MeV tot = 29±10±2 MeV Nsig = 64 ± 18 evts

DD

J/

PRL 96, 082003 (2006)

c2’

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-14

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X(3915) partial width

B(J/) = 69 16 +7 eV (JP=0+)

B(J/) = 21 4 +2 eV (JP=2+)

For comparison:: B(DD) = 180 50±30 eV

If X(3915) = Z(3930) = c2’ 0.08B(c2’J/)

B(c2’DD)

Huge for above-open-charm-threshold charmonium

-18

-5

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Could it be the Y(3930)?BKJ/PRL94, 182002

M≈3943 ± 17 MeV≈ 87 ± 34 MeV

B+

B0

M≈3915 ± 5 MeV≈ 33 ± 13 MeV

Good overlap withBaBar Y(3930) values

X(3915):

M: 3914 3 2 MeV,

: MeV,

PRL101, 082001PRD82, 011101

B+

B0

M≈3919 ± 5 MeV≈ 31 ± 12 MeV

281023

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K. Yi ICHEP 2010

m = MeV/c2

a 2nd one at

m=4275 MeV?

B(Y4140J/) 10%

(Y4140J/) 1.2 MeV

If B(B+K+ Y4140) B(B+K+J/)

B+ K+ J/

The CDF Y(4140)J/

D*D*ssDD**ss molecule? molecule? [cs[cscscs] tetraquark?] tetraquark?

29.20.3 /6.4143 cMeV

24.10

1.6 /3.15 cMeV

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Searched for Y(4140) in J/• No Y(4140) (efficiency is vNo Y(4140) (efficiency is v

ery low ~0.3%)ery low ~0.3%)

• White histograms are datWhite histograms are data, the shaded are normalia, the shaded are normalized zed and J/ and J/ sidebands sidebands eventsevents

• A few events accumulate A few events accumulate at 4.35 GeV in both J/at 4.35 GeV in both J/eee & e & modes modes

• Our upper limits disfavor Our upper limits disfavor the scenario Y(4140) beinthe scenario Y(4140) beingg

a Ds*a Ds*+ + Ds*Ds*--molecule with molecule with

JJPCPC=0=0++ ++ or 2or 2++++

[PRD80, 054019,2009][PRD80, 054019,2009]

JP=0+: ΓγγBr(Y(4140)) →J/) < 39 eV @ 90% C.L.JP=2+: ΓγγBr(Y(4140)) →J/) < 5.7 eV @ 90% C.L.

825 fb-1

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Fit to J/ invariant mass

1.14.6 1.33.2

7.06.4350 6.41.5

JP=0+: ΓγγBr(X(4350)) →J/) = eV

JP=2+: ΓγγBr(X(4350)) →J/) = eV

S.S.=3.9, const. bkgS.S.=3.2, linear bkg

825 fb-1

PRL 104, 112004 (2010)

• M= MeV/c2

• Γ= MeV/c2

• N (X(4350))=

•Excited P-wave charmonium? •Tetraquark? Fl. Stancu, arXiv: 0906.2485•D*

sD*s0 molecule at 4.34±0.09 GeV?

J.R.Zhang et al., arXiv:0905.4672

2.42.38.8

1.14.6 1.33.2

1.43.13 9.171.9

3.05.1 7.05.0

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e+e– to charm cross sections via ISR

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Use ISR to measure open charm exclusive final states

e-

e+ e+e+

e- s=(Ecm-E)2-p2

c c

ISR at B factories• Quantum numbers of final states are fixed JPC = 1– –

• Continuous ISR spectrum:– access to the whole √s interval

em suppression compensated by huge luminosity

– comparable sensitivity to energy scan (CLEOc, BES)

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DD DD* D*D*

DDπ

DD*π

Λ+c Λ

c

Sum of all exclusive contributions

Here D=D0 or D+ . The same for D*Only small room for unaccounted contributions

• Charm strange final states Limited inclusive data above 4.5 GeV

• Charm baryons final states

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• Full reconstruction of hadronic part

• ISR photon detection is not required

– but used if it is in the detector acceptance

• Translate measured Ds(*)+Ds

(*)- mass spectrum to cross section

• Ds+ are reconstructed using six decay modes: KsK+,K-K+π+, KsK-

π+ π+, η π + and η’ π +

e+e– →Ds(*)+Ds

(*)- via ISR

with full reconstructionγ

reconstructed

not reconstructed

if undetectable

Ds(*)+

s=E2cm-2EγEcm

e+

e–

e+

Ds(*)-

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Exclusive e+e–→Ds(*)+Ds

(*)- cross-sections

• A clear peak is seen at threshold near ψ(4040) mass in Ds+Ds

-

• Two clear peaks are seen at the ψ(4160) and the ψ(4415) masses in Ds

+Ds*-

• With limited statistics no structure are evident in Ds*+Ds*-

• Both the e+e-→ Ds+Ds*- cross section and R ratio exhibit an obvious dip

near the Y(4260) mass, similar to what is seen in e+e-→D*D* and in the total cross section for charm production.

arXiv:1011.4397 (accepted by PRD)

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Status of Status of SuperKEKB/Belle IISuperKEKB/Belle II

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• What is the next experimental step? Precision measurements

• Much larger sample needed for this purpose Super B factory

• Hopefully new phenomena might be seen:

– CPV in B and D decays from the physics outside the CKM scheme.

– Lepton flavour violations in decays.

• Physics models can be identified (if new effects are observed) or new ones can be constrained (if nothing is seen).

• Physics motivation is independent of LHC.

– If LHC finds NP, precision flavour physics is compulsory.

– If LHC finds no NP, high statistics B/ decays would be a unique way to search for the physics far beyond the TeV scale.

Further Continuation of Flavour Physics Further Continuation of Flavour Physics possible at a Super B Factorypossible at a Super B Factory

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How to do it? => Upgrade KEKB & BelleHow to do it? => Upgrade KEKB & Belle

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e- 7GeV 2.6 A

e+ 4GeV 3.6 A

Target: L = 8x1035/cm2/s

SuperKEKB

Colliding bunches

Damping ring

Low emittance gun

Positron source

New beam pipe& bellows

Belle II

New IR

TiN-coated beam pipe with antechambers

Redesign the lattices of HER & LER to squeeze the emittance

Add / modify RF systems for higher beam current

New positron target / capture section

New superconducting /permanent final focusing quads near the IP

Low emittance electrons to inject

Low emittance positrons to inject

Replace short dipoles with longer ones (LER)

SuperKEKB colliderSuperKEKB collider

The improvement in luminosity is due to the dramatic reduction of The improvement in luminosity is due to the dramatic reduction of beam size (beam size (σσyy ~1 micron -->50 nanometer) ~1 micron -->50 nanometer)

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21-24 Oct 2010 Charm2010

Plan and Expectation with SuperKEKBPlan and Expectation with SuperKEKB

Milestone of SuperKEKB

We will reach 50 ab-1

in 2020~2021.9 month/year20 days/month

Inte

gra

ted L

um

inosi

ty(a

b-1)

Peak

Lum

inosi

ty(c

m-2s-

1)

Commissioning starts In later half of 2014

Shutdownfor upgrade

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Status: TerminationStatus: Termination of KEKB on June 30, 2010 of KEKB on June 30, 2010 marked the start of SuperKEKB/BelleIImarked the start of SuperKEKB/BelleII

First physics run on June 2, 1999Last physics run on June 30, 2010Lpeak = 2.1x1034/cm2/sL > 1ab-1

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• 5.8 oku yen (M$) for Damping Ring (FY2010)• 100 oku yen (M$) for machine: Very Advanced

Research Support Program approved for FY2010-2012• 2010-2013: construction, installation• 2014(later half): commissioning

Funding and ConstructionFunding and Construction

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New Collaboration (Belle II)New Collaboration (Belle II)Belle II is a new international collaboration 360360 members members - 57 - 57 institutions institutions Regular collaboration meetings TDR (Technical Design Report) has been published

(arXiv:1011.0352arXiv:1011.0352)

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SummarSummaryy

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backup

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All possible two-body decays of ψ(3770), ψ(4040), ψ(4160), ψ(4415) are included

Significant effect of interference : model dependent!

To reduce model dependence

we need to measure exclusive cross sections to ope

n charm final states

Resonance shapes Interference term

Rres=RBW+Rint

Phys.Lett.B660,315(2008) BES fit to the inclusive R spectrum

Parameters of the JPC = 1– – conventional charmonia

ψ(3770), ψ(4040), ψ(4160), ψ(4415)

M, Γtot, Γee remain quite uncertain and model dependent

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How to improve luminosity?

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Zhen-An Liu 21-24 Oct 2010 Charm2010 54

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Belle II:Belle II:Belle Upgrade for the Super KEKBBelle Upgrade for the Super KEKB

SC solenoid1.5T

New readout and computing systems

CsI(Tl) 16X0

pure CsI (endcap)

new electronics (waveform sampling)

Aerogel Cherenkov counter + TOF counter

→ “TOP”

+ Aerogel RICH

Si vtx. det. 4 lyr. DSSD→ 2 DEPFET pixel lyrs. + 4 lyr. DSSD

/ KL detection 14/15 lyr. RPC+Fe

→ tile scint.

TDR: KEK Report 2010-1

CDC: Tracking + dE/dx small cell + He/C2H6

remove inner lyrslarge outer radiusfaster timingsmaller cell

→