New Physics in Rare Decays at Belle

Toru Iijima

Nagoya University

March 4, 2006KEK Theory Meeting 2006

“Particle Physics Phenomenology”

2

Conclusion

No New Physics Indication Yet in Rare Decays ! (except for some puzzles)

How significant is this fact ?

Many peoples expect NP at TeV.

3

Search for New Physics in 3rd Gen. Quark (B) and Lepton () Decays

Hadronic Penguin decayssome puzzles ?

Radiative decays

Electroweak decays

Tauonic decays

Tau decays 　Lepton flavor violation

Talk Outline

, .b s d etc

, .b c etc

.etc

Figure by Dr.Hayasaka (Nagoya Univ.)

, .b s s etc

At present and future (Super-B)

4

Pattern of B Decays B meson is the heaviest meson in the 3rd generation and

its decay has several patterns.– Large b quark mass– Huge top mass– Small Vcb– Non-zero Vub

B meson is an unique lab. To explore flavor mixing and CP violation. 1, , 3

- Vcb, Vub, Vtd

Many loops - box and penguin

W exchange coupled to

b u

l

W

ubV

b s

b d

d bW W

t,c,u

t,c,u

b du

u

g

b s

, Z

t

W b s

W W

t

b c

W

b

u

W

5

Belle Detector7 sub-detectors for precise

– Vertexing, – Tracking, – Particle ID, – Calorimetry

6

Belle Collaboration

13 countries, 57 institutes, ~400 collaborators

IHEP, ViennaITEPKanagawa U.KEKKorea U.Krakow Inst. of Nucl. Phys.Kyoto U. Kyungpook Nat’l U. EPF Lausanne Jozef Stefan Inst. / U. of Ljubljana / U. of MariborU. of Melbourne

Aomori U.BINPChiba U.Chonnam Nat’l U.U. of CincinnatiEwha Womans U.Frankfurt U.Gyeongsang Nat’l U.U. of HawaiiHiroshima Tech.IHEP, BeijingIHEP, Moscow

Nagoya U.Nara Women’s U.National Central U.Nat’l Kaoshiung Normal U.National Taiwan U.National United U.Nihon Dental CollegeNiigata U.Osaka U.Osaka City U.Panjab U.Peking U.U. of PittsburghPrinceton U.RikenSaga U.USTC

Seoul National U.Shinshu U.Sungkyunkwan U.U. of SydneyTata InstituteToho U.Tohoku U.Tohuku Gakuin U.U. of TokyoTokyo Inst. of Tech.Tokyo Metropolitan U.Tokyo U. of Agri. and Tech.Toyama Nat’l CollegeU. of TsukubaUtkal U.VPIYonsei U.

7

e+ source

Ares RF cavity

Belle detectorSCC RF(HER)

ARES(LER)

The KEKB Collider e- (8.0GeV) × e+ (3.5GeV)

⇒(4S) →BB⇒Lorentz boost: = 0.425

Finite crossing angle- 11mrad ×2

Operation since 1999.

Peak luminosity 1.63 x 1034 cm-2s-1 !Integrated luminosity >560fb-1

8

KEKB PerformanceRecords as of Mar.1,’06 L peak = 1.63x1034cm-2s-1

L day = 1182.5pb-1/day L int = 563.3 (Mar 1,’06)

CESR

KEKB Lint/month

Record = 27.9fb-1

9

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 !

10

Rare Decay Milestone

Observation of BK l+ l-Large CP Violation in B

Observation of Large CPV and evidence of direct CPV in B+-

Beginning of B->K0 saga

Direct CPV in B0K+

Observation of bd

FB asymmetry in BK* l+l-

Successful operation of B factories has enabled us to–Measure the B decays in different patterns.–Measure not only branching fraction, but also more details

•CP asymmetry•B+/B0 difference•Distribution (Mx in bs, AFB in BK*ll)

Successful operation of B factories has enabled us to–Measure the B decays in different patterns.–Measure not only branching fraction, but also more details

•CP asymmetry•B+/B0 difference•Distribution (Mx in bs, AFB in BK*ll)

11

Direct CPV in BK Remarkable progress in the B-factory era.

CLEO w/ 2.6M BB: [PRD53,1039(1996)]

PID for high momentum K/.

386 x 106 BB

hep-ex/0507045

12

K puzzle ? Ratio of branching fraction Different sign of

Acp(K+-) and Acp(K+0).0

0

( )2 1.00 0.08

( )c

B B KR

B B K

0

0 0 0

1 ( )0.79 0.08

2 ( )n

B B KR

B B K

Possible reasons; Large EW-penguin (with large phase) Large color suppressed diagram ? Or both

NP (ex. Z’) ??

No conclusion yet.

13

Possible to search for NP in theoretically clean way.

Many observables;– Branching fractions– Mixing induced CPV– Direct CPV– Forward-backward asym.– Ratio of exclusive modes

bs/sl+l-

b s

t

W b s

, Z

t

W b s

W W

t

M(H+) > 350 GeV alreadyin TYPE II 2HDM

Effective Hamiltonian for bs10

*

1

4( ) ( )

2F

eff ts tb ii

GH V V C O

|C7| by BXs, Sign of C7, C9, C10 by BXsll

14

bs BK*, PRD69,112001 (2004)

– 85.0MBB

0 *0

*

0.0260 0.026

*

( ) 4.01 0.21 0.17

( ) 4.25 0.31 0.24

0.012 0.044

( ) 0.015 0.044 0.012CP

Br B K

Br B K

A K

0 *0

*

0.0260 0.026

*

( ) 4.01 0.21 0.17

( ) 4.25 0.31 0.24

0.012 0.044

( ) 0.015 0.044 0.012CP

Br B K

Br B K

A K

bs(inclusive) PRD93,061803 (2004)

– 152MBB

0.30 0.11 40.31 0.07

( )

(3.55 0.32 ) 10

Br b s

0.30 0.11 40.31 0.07

( )

(3.55 0.32 ) 10

Br b s

140fb-1

E > 1.8 GeV

(M.Nakao @ CKM2005)

15

bd 386M BB qq background suppression;

– Event shape– Decay vertex– Flavor tagging quality

Hep-ex/0506079v2BELLE preprint 2006-5Submitted to PRL

0.42 0.090.36 0.08( ) 0.55Br B

0 0 0.37 0.070.33 0.06( ) 1.25Br B

0 0.34 0.050.27 0.10( ) 0.56Br B

0.34 0.100.31 0.09( ( , ) ) 1.32Br B

w/ constraint from isospin relation

0.026 0.0180.025 0.0150.199 (exp.) ( .)td tsV V theo 0.026 0.0180.025 0.0150.199 (exp.) ( .)td tsV V theo

w/ Br(BK*)

16

Measurement of B(BXsl+l-)

Semi-inclusive technique– Xs is reconstructed from K+ or K

s + 0-4 (at most one 0 is allowed)

– MXs < 2.0 GeV

Electron or muon pair– Mll>0.2GeV– Charmonium veto

140/fb data

Theoretical prediction by Ali et al.

Wrong flavor

MXs q2

M. Iwasaki et al. submitted to PRD, hep-ex/0503044

17

C7 = -C7SM

Constraints on Ci from B(BXsl+l-)

Clean prediction for B(BXsll) with 1<q2<6GeV2 is available.– Combine Belle and Babar results– Sign of C7 flipped case with SM C9 and C10 value is unlikely.

P.Gambino, U.Haisch and M.Misiak PRL 94 061803 (2005)

BF Belle Babar WA SM C7 = -C7SM

q2>(2m)2 4.11±1.1 5.6±2.0 4.5±1.0 4.4±0.7 8.8±0.7

1<q2<6GeV2 1.5±0.6 1.8±0.9 1.60±0.5 1.57±0.16 3.30±0.25

C10NP C10

NP

C9NP

Donut : 90% CL

allowed region

C7SM

SM

18

BK*ll FB Asymmetry Good electroweak probe for bs loop.

q2 distribution has different pattern depending on sign(C7).

*10 9 7( ( ) ( ) )eff

FBA C sC s r s C

FBA

2( )GeV2q

b s

, Z

t

W b s

W W

t

q0(the point w/ AFB=0) is sensitive for New PhysicsSM; q0

2=(4.2±0.6)GeV2

B

K*

l

l

B

K*

l

l

Forward Backward

T. Rizzo

M=1.5TeV

M=1 TeV

AFB w/ KK gravition exchange

19

A9/A7

A1

0/A

7

AFB: Belle Summer ‘05

357fb-1 (386M BB) N(K*ll)=114+-14 (purity 44%) Unbinned M.L. fit to d2/dsd(cos)

– 8 event categories• Signal + 3 cross-feed + 4 bkg.

– Ali et al’s form factor– Fix |A7| to SM

– Float A9/A7 and A10/A7

Results;w/negative A7 (SM like)

w/positive A7

ＳＭA9/A7

A10/A7

Sign of A9A10 is negative !

See Hep-ex/0508009 &A.Ishikawa’s talk at EPS05

20

Prospect at Super-B

@ 5ab-1

C9 ~ 11%C10 ~14%q0

2/q02 ~11%

1000 pseudo experiments w/ SM input values

Expected precision

5% at 50ab-1

21

Bl; leptonic decays

Proceed via W annihilation in the SM.

Branching fraction is given by

Provide information of fB|Vub|– |Vub| from BXu l fB cf) Lattice (~16%)

– Br(Bl)/md |Vub| / |Vtd|

Expected branching fraction3| | (3.67 0.47) 10ubV

(0.196 0.032)Bf GeV 5( ) (9.3 3.9) 10Br B

4 6 9~ 1 10 ( ) :~ 0.5 10 ( ) :~ 1 10 ( )Br e

22

Status of Leptonic Decay Search

Results @ Summer’05

23

Full Reconstruction Method

Fully reconstruct one of the B’s to tag– B production– B flavor/charge– B momentum

Υ(4S)

e (8GeV)

e+(3.5GeV)

B

B

full (0.1~0.3%)reconstructionBD etc.

Single B meson beam in offline !

Decays of interests BXu l , BK BD,

Powerful tools for B decays w/ neutrinos

24

Fully Reconstructed Sample

Belle (253fb-1): 275M BB 2.5x105 B0B0 + 4.2x105 B+B-

25

BStatus (Belle LP05/EPS05)

NBB (produced) = 275M NB+B- (full recon.)

= 4.0 x 105 (purity 0.55) Searched decay

modes

– Cover 81% of the decay

Event selection– Residual ECL energy

– Total net charge

etc.

, e 0, ,

0ii

Q

0.3residualE GeV

Obtained EresidualK.Ikado’s talk at EPS05hep-ex/0507034

4( ) 1.8 10 (90% )Br B CL

26

Prospect

Will soon reach the SM.– 3 at ~700 fb-1

– 5 at ~2 ab-1

Expected precisionat Super-B– 13% at 5 ab-1

– 7% at 50 ab-1

B will be the next major milestone ofthe Belle mission for rare decay search !B will be the next major milestone ofthe Belle mission for rare decay search !

27

Impact to Charged Higgs Br. with exchangeH

90%CL excluded regionat present

95% CL excluded regionat 5ab-1 (if Bobs = BSM)

rH

tan/mH

b

u H/W

28

Charged Higgs in BD Charged Higgs modifies semileptonic decay rates.

cb

W

(the heaviest lepton) is the most sensitive.

( )tan cotb c um m

tanm cb

H

+ 　 exchangeH exchange (SM)W

Tanaka/ Miura

29

BD (MC studies)

Use fully reconstructed samples. T decay modes

Analysis cuts;– Reject events w/ p, KL– Reject D(*) contamination

– No remaining charged or 0 tracks– ECL residual energy

– Angle between two ’s

– Missing mass

0 02142 10MeV/D Dm m c

100residualE MeV

1.0 cos 0.8

2 2 21.2 ( / )B Dp p p GeV c

Signal

BG

, e , ,

30

Cont’d

5ab-1 50ab-1

Mode Nsig Nbkg dB/B Nsig Nbkg dB/B

280 55012.7 7.9%

2800 550040.3 2.5%

620 3600 6200 36000

0 ( )D

0 ( )D h

Expectation at 5 / 50 ab-1 for B+ decay

5 observation possible at 1ab-1

Signal selection efficiency0

0

( )

( )

e

e

D e

D

0

0

( )

( )

D

D

10.2%2.6%

26.1%13.3%

Major background sourceMissing charged and tracks from BD(*) l X (incl. slow )

31

Cont’d

(Fo

rm-fa

ctor

) ~15

%

(Fo

rm-fac

tor)

~5%Constraint

From bs

Present limit From B

32

Lepton Flavor ViolationQuarks have flavor mixing.

Neutrino mixing has been found.What about charged leptons ?

e

e

? ?

(Original figure by Dr. Kuno / Osaka Univ.)

B factory is also a tau factory

33

l SUSY + Seasaw Large LFV

l3ll

Br()=O(10-7~9)

2

32

4

262

( a101

) t nL

L

SUSY

BTeV

m

mr

m

3l,l • Neutral Higgs mediated decay.• Important when MSUSY >> EW scale.

462

7 322

tan 100

60

( 3 )

4 10A

L

L

B

G

m

r

m

m

eV

( ) : ( 3 ) : ( )

5 :1: 0.5

Br Br Br

( )e

0

( )e223(13)l

(m )

( )s

( )s

h

34

Analysis Method

Signal extraction– Calc. Minv and DE

• DE=Erec-Ebeam

– Blinded signal region Event selection study

– Estimate backgroundusing sideband data

– Open blind and estimate signal yield• Estimate upper limits

Signal MC of Signal

region

Background

35

/eat Belle

Background: /e + ISR (or beam background) Small amount of mm events in E>0

Br<3.1x10-7 at 90%C.L.

PRL 92, 171892 (2004).

Br<3.1x10-7 at 90%C.L.

PRL 92, 171892 (2004).

86.3fb-1 datae

Br<3.9x10-7 at 90%C.L.

PLB 613, 20 (2005).

Br<3.9x10-7 at 90%C.L.

PLB 613, 20 (2005).

36

l Belle: 87.1fb-1, PLB 598, 103 (2004)

Br<(1.1~3.5)x10-7 at 90%C.L.

Background: low level– qq for E<0, QED( or Bhabha) for DE>0

Signal region

37

B.R. Summary

Br < O(10-6) in PDG (by CLEO) Br < O(10-7) by Belle and BaBar

38

Super B-factory : >10 times more data

– B.R. sensitivity: ~1/n for negligible BG case ~1/n for BG dominating modes

Future prospect

39

Future prospect (2)

Possible sensitivity with Super B-factory – Red band for 5~10ab-1

SuperB-factory

40

l SUSY + Seasaw Large LFV

Constraint to NP

Br()=O(10-7~9)

0tanβ=30,A =0,μ>0Gaugino mass = 200GeV

Super-BPresent Belle

2

32

4

262

( a101

) t nL

L

SUSY

BTeV

m

mr

m

3l,l • Neutral Higgs mediated decay.• Important when MSUSY >> EW scale.

462

7 322

tan 100

60

( 3 )

4 10A

L

L

B

G

m

r

m

m

eV

41

Interplay between B and

J.Hisano @ Tau04Workshop, Nara,Nov, 2004.

J.Hisano, Y.ShimizuPLB565(2003)183.

42

Concluding Remarks

No New Physics Indication Yet ! Need more luminosity.

This year:Crab cavity installation

Future: Super-KEKB

Stay tuned !

43

Future

Let’s discuss together– Role of flavor physics– Synergy with LHC YES NO

YES 1 3

NO 2 4LHC

Flavor Phys(ex. Super-B)

NP evidence

1. We will be busy! Scenario of studies ?2. Scenario of studies ? 3. How significant is the null result at F.P. to constrain NP model.4. Where do we go ?

1. We will be busy! Scenario of studies ?2. Scenario of studies ? 3. How significant is the null result at F.P. to constrain NP model.4. Where do we go ?

44

CERN Flavor WS

Nov. 7-10, 2005 Feb. 6-8, 2006 May.15-17, 2006 Final report at

2006/end or 2007/beg.

Discuss synergy between Flavor Physics (B/C/K/t/m etc.) and LHC.

Bench mark model & parameters for studies.

Let’s discuss together !

45

Backup

46

Radiative Decays

Inclusive Br(bs) |C7|, SF for |Vub| BK* isospin asymmetry (+-)sign of C7

Mixing induced CPV Direct CPV in BXs BXd

Summary by M.Nakao1st Super-B workshopat Hawaii

47

B0KS0 tCPV: Belle Summer ‘05

386MBB M(Ks0) < 1.8GeV/c2

– NP effect is independent of the resonance structure. Two M(Ks0) regions(MR1:0.8-1.0GeV/c2 / MR2: <1.8GeV/c2) 70+-11 (45+-11) events in MR1(2).

Atwood, Gershon, Hazumi, Soni, PRD71, 076003 (2005)

ResultS= +0.08 ±0.41 ±0.10 　A= +0.12±0.27±0.10

Good tag (0.5<r<1.0)

0.0050.0110.051 / 0.038Acpdir(BXs)

0.040.140.41 / 0.10Acpmix(BK*K*Ks0)

50ab-15ab-1Present Belle (stat./syst.)

48

Acp(BXs) vs SUSY models

mSUGURAtan=30

U(2)tan=30

SU(5)+R

tan=30degenerate

SU(5)+R

tan=30non-degenerate

( )gm GeV

mSUGURAtan=30

U(2)tan=30

SU(5)+R

tan=30degenerate

SU(5)+R

tan=30non-degenerate

( )gm GeV

Mixing CPVDirect CPV

Acp

dir

Acp

mix

5ab-1 50ab-1

T. Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanakahep-ph/0306093, also in SuperKEKB LoI

49

Constraint to Charged Higgs

Once branching fraction is measured, we can constrain R.

tanW

H

MR

M

Form factor error

M.Tanaka, Z.Phys. C67 (1995) 321

11R at 5ab-1 can be determined experimentallyby B semiletonic decays