Rare and Radiative B Decays M.-Z. Wang ( 王名儒 ) on behalf of the Belle Collaboration...
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Transcript of Rare and Radiative B Decays M.-Z. Wang ( 王名儒 ) on behalf of the Belle Collaboration...
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.
2005/10/4 ICFP2005 Rare Radiative B Decays
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
2005/10/4 ICFP2005 Rare Radiative B Decays
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.