Super B factory plan at KEK

Masa YamauchiKEK

Super B Factory WorkshopApril 20-22, 2005 Honolulu

Why, how, what, who, when and how much?

Discovery of CPV in B decays

Study of NP effect in B and decays

Identification of SUSY breaking mechanism

time or

integrated luminosity

Yes!!

sin21, CPV in B,3, Vub, Vcb, bs,bsll, new states etc.

AnomalousCPV in bsss

NP discoveredat LHC(2010?)

Now400 fb-1

if NP=SUSY

Why? - Roadmap of B Physics

Precise test of SMand search for NP

Motivations for Super KEKB

Once New Physics is discovered and its mass scale is determined, next is to study its flavor structure and CP violation, where B physics can play a unique role.

TCPV in b→sss ≠ b→ccs : 3.8 Polarization in penguin dominated B→VV decays ACP(B±→K± 0) ≠ ACP(B0→K± )

±

1. Possible anomalies observed in B decays

2. New physics will be found soon at LHC.

3. ee B factory with L=3.5×1035 is competitive with LHCb.

These MUST be clarified.

Anomalous CPV hints new physics?

-f x Sf

Belle + BaBar, 2004

top

W

penguin decay

Ave. CPV = 0.41±0.07

Ave. CPV = 0.726±0.037

equalif only SM

3.8 deviationobserved

Tree decayb c

c

d s

d_

_

_B

J/

KS

W

Other Evidences for New Physics

fL (B→VV)ACP(B→Kπ)

Comparison with LHCb

hep-ex/0406071SuperKEKB LoI

Comparison K* (which is Golden mode at LHCb) yield by LHCb is 2.7

times larger than K*ll yield by Super Belle. Need 1036 machine and better detector(PID, vertex)/analysis.

A7 is fixed to the value obtained from bs LHCb cannot measure B(bs), so they should use our value

or float A7.

K*l+l- evts/yearS/N

A9 A10 A7 from bs

s0

LoI Belle(e + )

N.A.N.A.

32% 44% 2.5(exp)+2.5(theo)%?

32%

Toy Belle(e + )

16401.7

11% 13%. 2.5(exp)+2.5(theo)%?

11%

LHCb( only)

4400>0.5

6.5%* 6.9%* N.A. 7.4%If A7 is fixed.

3 times better

*just scaling Belle value with evts.

A.Ishikawa6th Workshop on Higher Lum. B FactoriesNovember 2004

How? - SuperKEKB Parameters

Crab Cavity

Interaction RegionCrab crossing

=30mrad.y*=3mm

New QCS

What? – SuperKEKB Design

Linac upgrade

More RF power

Damping ring

New Beam pipe

L

2ere

Iy

y*RLRy

Increase beam currents•1.6 A (LER) / 1.2 A (HER) → 9.6 A (LER) / 4.1 A (HER)

Smaller y*

• 6 mm→3 mm

Increase y

• 0.05→0.28(W-S)

L=3.5x1035cm-2s-1

8GeV (e+, 4.1A) 3.5GeV (e-, 9.6A)

Super-KEKB (cont’d)

Head-on collision w/ Crab cavityNew crab cavity

Ante-chamber /solenoid for reduction of electron clouds

Circular-chamber

Build-up ofelectron clouds

Ante-chamberAnte-chamberwith solenoid field

Will be tested in 2006.

Fight for Higher Beam Current

ARES for SuperKEKB

SCC for SuperKEKB

KEKB Upgrade Scenario

~1010 BB/year !!& similar number

of +-

Lpeak = 1.41034cm-2s-1

Ltot = 330fb-1 (Nov.30, 2004)

1.4x1034

330 fb-1

5x1034

~1 ab-1

5x1035

~10 ab-1

Lpeak (cm-2s-1)Lint

Crabcavities

Major upgrade ofKEKB & Belle detector(>1yr shutdown)

world records !

Belle Upgrade

SC solenoid1.5T

New readout and computing systems

CsI(Tl) 16X0

pure CsI (endcap) Aerogel Cherenkov counter + TOF counter

“TOP” + RICH

Si vtx. det. 4 lyr. DSSD 2 pixel/striplet lyrs. + 4 lyr. DSSD

Tracking + dE/dx small cell + He/C2H5

remove inner lyrs.

Use fast gas

/ KL detection 14/15 lyr. RPC+Fe

tile scintillator

Q1: Does DC work with L=3.51035?

If NO,– Need Si tracker.– EM cal, solenoid and iron structure have to be

rebuilt!!

If YES,– Upgrade the present Belle detector.

New detector

87.57

6.56

5.5

4

3.532.5

21.51

0.5

4.55

HER Radiative Bhabhas

32.5

2 1.51

0.5

LER Radiative Bhabhas

-7.5 -5 -2.5 0 2.5 5 7.5

0

10

20

30

-10

-20

-30

m

cm

M. SullivanFeb. 8, 2004API88k3_R5_RADBHA_TOT_7_5M

3.1 G

eV

3.1 G

eV

9 GeV

9 GeV

PEP-II Radiative Bhabhas

LER radiative gammas

0.511.5

22.5

3

LER radiative bhabhas

HER radiative gammas

7654

0.5

1

2

3

HER radiative bhabhas

KEKB Interaction Region

0

10

20

30

-10

-20

-300 2.5 5 7.5-2.5-5-7.5m

cm

HER

LER

8 GeV

3.5 GeV

M. Sullivan Nov. 9, 2004 B3$KEK2_IR_RADBHA

Detector

Detector

CSL CSR

QCSL QCSR

CSL CSR

QCSRQCSL

Q1EL

Q1ER

Q2PL

Q2PR

0.5

11.5

22.5

3

LER gammas

0.5

12

3

4 5

6 7

HER gammas

Super KEKB IR

0

10

20

30

-10

-20

-300 2.5 5 7.5-2.5-5-7.5m

cm

M. Sullivan Nov. 13, 2004B3$_SUPER_KEK_RADBHA

HER

LER

8 GeV

3.5 GeV

Detector

QCSRQCSL

QC1LEQC2LE

QC2LP

QC1RE

QC2RE

QC2RP

Detector

Difference of QCS position is the reasonShower caused by over bend particle

Pointed out by M.Sallivanin 6th HLWS (Nov,2004)

Rad. Bhabha BG sim. for Super-Rad. Bhabha BG sim. for Super-KEKBKEKB

FWDEndCap

BWDEndCap

Barrel

L=1034 /cm2/s

~4 % oftotal BG

L=25x1034

/cm2/s

Expected BGfrom other

sources with heavy metaltotal ~ 1.5 ton

Realistic designbased on discussionwith QCS group

Average Vacuum Average Vacuum 5x105x10-7-7 Pa Pa

1st layer

Super-KEKB (current) design

Does Belle-CDC work with L=3.51035 ?

r = 15cm

Layer

Hit

rat

e/w

ire (

k Hz)

Exp 27 Run 206

HER 1.1ALER 1.5AL=9.6x1033cm-1s-1

MainInner

Cathode

Layer

Num

ber

of h

its

Bhabha ev.

2000

2002

Layer 49

Layer 49

Layer 1

Layer 1

Layer 3

Layer 3

Radiation damage to the present CDC

Efficiency for Bhabha tracks

Gain drift

No rad. damage has been observedafter 0.2C/cm irradiation.

Track Reconstruction under High Background

5 10 15 200

Background factor

5 10 15 200

Background factor

0

20

40

60

80

100

Rec

onst

ruct

ion

eff.

(%

)

High pT (B)

Low pT (BD(Ds))

will be improved by replacingthe inner part by Si.

MC + real background at Belle

Tentative conclusion

Drift chamber can be used in L=3.51035 at r>15cm.

The detector is designed as an upgrade of Belle detector.

Baseline Design of SuperBelle

Vertexing detector: “striplet” + APV25 or pixel Central drift chamber: small cell + faster gas PID device: TOP(B) + Aerogel RICH(E) EM calorimeter: Pure CsI + tetrode (E) Scintillator KLM Pipelined DAQ Much bigger computing system

Issue

Belle/BaBar joint workshop– 2004, Jan (Hawaii)– 2005, April (Hawaii)

6 workshops to discuss physics, detector and accelerator issues.– 2001, Aug: 1st workshop at KEK– 2002, Jan (KEK)– 2002, Aug (Shonan)– 2003, Feb (KEK)– 2003, Sep (Shuzenji)– 2004, Nov (KEK)

Workshop at Shuzenji(Sep. 24-26, 2003)

Who? – Open Question

• Letter of Intent for KEK Super B Factory (KEK Report 2004-4)• Physics at Super B Factory (hep-ex/0406071)

• Letter of Intent for KEK Super B Factory (KEK Report 2004-4)• Physics at Super B Factory (hep-ex/0406071)

268 authors

Mt. Tsukuba

Injection Linac

Tsukuba exp. hallKEKB ring

e(HER, 8GeV) + e(LER, 3.5GeV) (4s) BB ( 1nb) Lorentz boost = 0.425Finite angle crossing : 211 mrad

Where?

When? - Proposed Schedule

2004 05 06 07 08 09 10 11 12

KEKB SuperKEKB>1000fb-1

Calendar year

Crab cavity

KEKBmachine

SuperKEKB const.

J-PARC 1 construction ILC constructionConstruct.fund

“Minor” upgrade “Major” upgradeBelle

Operationfund

T2K

How much? - Estimated Cost

Summary

Why? – Search for new origin of flavor mixing and CP violation

How? – Increase NB, decrease y*, and crab crossing: L=3.51035/cm2/s

What? – New beam pipe, crab cavity, new injector with damping ring. Belle will also be upgraded assuming DC is usable.

Who? – YOU! Where? – Upgrade existing KEKB. When? – JFY2009 and 2010 How much? – US$450M