Rare and Radiative B Decays Rare and Radiative B Decays

M.-Z. Wang (王名儒 )on behalf of the Belle Collaboration

ICFP2005

OutlineOutline

•IntroductionIntroduction

•B → XB → Xsγ moments

•B → B → B+pΛγ

•B → B → Xsl+l-

•B → B → K*l+l- FB Asym.

• b → b → d γ

•SummarySummary

2005/10/4 ICFP2005 Rare Radiative B Decays

Motivation and ReviewMotivation and Review

C7

C7,C9,C10

2005/10/4 ICFP2005 Rare Radiative B Decays

Integrated LuminosityIntegrated Luminosity

1.6

229M BB

2005/10/4 ICFP2005 Rare Radiative B Decays

B → XB → Xsγ from a sum of 38 exclusive decay modesB → XB → Xsγ from a sum of 38 exclusive decay modes

Eγ>1.9 GeV

hep-ex/0508004, 88.9 MBB

2005/10/4 ICFP2005 Rare Radiative B Decays

B → XB → Xsγmoments from measured spectrumB → XB → Xsγmoments from measured spectrum

Consistent with theory

2005/10/4 ICFP2005 Rare Radiative B Decays

hep-ex/0507001, 88.5 MBB

Inclusive B → XInclusive B → Xsγand AcpInclusive B → XInclusive B → Xsγand Acp

Use lepton tagging

consistent with zero

2005/10/4 ICFP2005 Rare Radiative B Decays

EEγ spectrum of B → X B → Xsγ EEγ spectrum of B → X B → Xsγ 140fb-1

2005/10/4 ICFP2005 Rare Radiative B Decays

Retrieving true moments from Retrieving true moments from measurementsmeasurementsRetrieving true moments from Retrieving true moments from measurementsmeasurements

2005/10/4 ICFP2005 Rare Radiative B Decays

Comparing with theoryComparing with theory

hep-ex/0508005

2005/10/4 ICFP2005 Rare Radiative B Decays

B+pΛγB+pΛγ

PRL 95, 061802, 2005Simultaneous fit on BpΛγ and BpΣ0γSignal Yield for BpΛγ with MpΛ<2.4GeV/c2: 34.1Statistical Significance: 8.6σ

BF(BpΛγ ): 2.16 ± 0.20x10-6

BF(BpΣ0γ):<4.6 x 10-6

140fb-1

pΛγSignal

+7.1- 6.6

+0.58- 0.53

bsγ MC

2005/10/4 ICFP2005 Rare Radiative B Decays

Photon energy and Angular distributionPhoton energy and Angular distribution

Fit results in bins of cosθX with MpΛ<4.0GeV/c2

(Assuming XpΛ, calculated in X rest frame.) Λ

γ

p

θx

bsγ MCSignal Yield

qq backgroundSignal Yield

Lab frame X frame

2005/10/4 ICFP2005 Rare Radiative B Decays

B → B → K(*)l+l-B → B → K(*)l+l-

hep-ex/0507009, 229 M BBAssuming charged equals to neutral and

2005/10/4 ICFP2005 Rare Radiative B Decays

Decay width for bsl+l- decayDecay width for bsl+l- decay

eff eff eff eff eff *9 10 7 7 9

22 5 *22

3

2 2 2

ˆ1ˆ 4 48

2ˆ1 2 4 1 12Re

ˆ

F b ts tbem

C

d b s G m V Vs

ds

s C C Cs

C

Decay width for bsll can be described with Wilson coefficients.

Interference term

sign of C7 relative to C9 as well as absolute values |Ci| can be determined !!

SM

Sign of C7 flipped case

T.Goto et al. PRD 55 4273 (1997)

2005/10/4 ICFP2005 Rare Radiative B Decays

Measurement of B(BXsl+l-)Measurement of B(BXsl+l-)

Semi-inclusive techniqueXs is reconstructed from K+ or Ks + 0-4 (at most one 0 is allowed)

MXs < 2.0 GeVElectron or muon pair

Mll>0.2GeVCharmonium veto

140/fb data

Theoretical preduction by Ali et al.

Wrong flavor

MXs q2

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

2005/10/4 ICFP2005 Rare Radiative B Decays

Constraints on Ci from B(BXsl+l-)Constraints on Ci from B(BXsl+l-)

Clean prediction for B(BXsll) with 1<q2<6GeV2 is available.Combine Belle and Babar resultsSign of C7 flipped case with SM C9 and C10 values 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

C7SM C7 = -C7

SMC10NP C10

NP

C9NP

Donut : 90% CL allowed region

2005/10/4 ICFP2005 Rare Radiative B Decays

New Measurement of AFB(q2) in K*llNew Measurement of AFB(q2) in K*ll

Forward-backward asymmetry is induced by interference btw virtual photon and Z0 contributions.Relative signs and magnitudes of C7 to C10 and C9 to C10 can be determined from AFB(BK*ll)!!

We do not use Ci but Ai which is leading coefficients.

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Signals for BK*l+l-Signals for BK*l+l-

357/fb data 386x106 BB pairs

Electron or muon pairCharmonium veto

K*(K+-, Ks+, K+0)|MK – MK* | < 75MeV

Signal yieldK*ll 114 14, purity 44%

Null test sample K+ll 96 12, purity 57%K+ll has no asymmetry.

hep-ex/0508009

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Fit results for ratios of Wilson coefficientsFit results for ratios of Wilson coefficients

Null test with K+ll

Projection to AFB

SM

Best fit for negative A7 (SM like)

J/ ’

Best fit for positive A7 (non-SM like)

(This solution is also allowed)

Unbinned fit projection

2005/10/4 ICFP2005 Rare Radiative B Decays

Confidence contours for Wilson Coef.Confidence contours for Wilson Coef.

For any allowed A7, we obtain 95% CL

Sign of A9A10 is negative!!

Sign of A9A10 flipped case is excluded

The first and third quadrantsSign of A7A10 is not determined yet.

The second and fourth quadrants

fit result

A7A10 sign flipped (to SM)

A9A10 sign flipped

Both A7A10 and A9A10 signs flipped

ＳＭA9/A7

A10/A7

SM

2005/10/4 ICFP2005 Rare Radiative B Decays

Motivation for b → b → d γ Motivation for b → b → d γ Complementary to the Tevatron Bs mixing program

2005/10/4 ICFP2005 Rare Radiative B Decays

Observation of b → b → d γ Observation of b → b → d γ

2005/10/4 ICFP2005 Rare Radiative B Decays

Combined fit resultsCombined fit results

2005/10/4 ICFP2005 Rare Radiative B Decays

Constraints on |Vtd/Vts|Constraints on |Vtd/Vts|

2005/10/4 ICFP2005 Rare Radiative B Decays

Summary of B → XB → Xsdγ Summary of B → XB → Xsdγ

HFAG releases new world average after major international conference

Web Site: http://www.slac.stanford.edu/xorg/hfag/

2005/10/4 ICFP2005 Rare Radiative B Decays

Summary of B → B → Xsl+l-Summary of B → B → Xsl+l-

2005/10/4 ICFP2005 Rare Radiative B Decays

SummarySummary

Radiative B decays are well established, more tests can be done with various aspects.First determination of the Wilson coef. from B → B → K*l+l- (Xsl+l-) decays. First observation of b → b → d γ.Thanks to HFAG, one can have easy access to up-to-date information.Looking forward to unexpected new physics with a much larger data set – Super KEKB-factory talk by M. Hazumi.