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Hadronic B and D decays studies at B A B AR. F. Couderc (LAPP, Annecy) @ Moriond QCD05 On behalf of the B A B AR collaboration. Introduction CP related analysis B + ( + - 0 ) D K + decay and asymmetry B D s + X - light analysis B + D s + - - PowerPoint PPT Presentation
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F. Couderc (LAPP, Annecy) @ Moriond QCD05
On behalf of the BABAR collaboration
Hadronic Hadronic BB and and DD decays studies at decays studies at
BBAABBARAR
Introduction • CP related analysis B+ (+-0)D K+ decay and asymmetry
B Ds+ X-
light analysis
B+ Ds+ -
B0 Ds+ a0(2)
-
B+ K*+0 (K+ 0)0 decay
B+ + & ’+ and others…
Conclusion
• Non CP related analysis
• B0 Ds*+ D*- decays and Ds BR
• Search for B+ D(*)+Ks0 decay
• B J/ D decay• c
0 production
New resultUpdated result
F. Couderc - Moriond QCD 2005
2
Introduction (1)Introduction (1)
Run 5 : COMING SOON
Run 1-4 : 244 fb-1 on peak data
All results shown here are preliminary
F. Couderc - Moriond QCD 2005
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Key variables – Introduction (2)Key variables – Introduction (2)
Sig Box
= (10-30) MeV
(mES) 3 MeV
B energy in the (4S) frame:
• Reco’d Energy : EB* = E*
Breco
• Beam energy : EB* = E*
beam
e- (9 GeV) e+
(3.1 GeV)(4S)
EE beam
ee
B
qqs **
22
reco
mES : B mass using
beam energy
E : difference between beam and reco’d energy
F. Couderc - Moriond QCD 2005
4
CP related analysisCP related analysis
F. Couderc - Moriond QCD 2005
5
continuum bkg
continuum+bb bkg
all
Two diagrams to reach the same final state CP
Advantage :
A(D03) A(D03)
BB++((++--00))D D KK+ + decay and asymmetrydecay and asymmetry
Fit projection on
B-
B-
3D (E, 2 NN to discriminate background) MLL fit : Nsig = 133 23 events
Signal enriched
L = 229 106 BB pairs B =
(5.51.00.7)10-6
= 0.020.160.03
Possible measurement with a Dalitz analysis technique
F. Couderc - Moriond QCD 2005
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B B D Dss+ + XXlightlight – – Motivations Motivations
sin(2) from CP violation in : B 0 D+ X-light decays
with X-light - , a0
- , a2- but this needs r
( )
A(B0D+X-)
B 0
B0A(B0D+X -)
CKM allowedCKM suppressed
B0 B 0
B 0
2
r = A(B0 D+ X-
light )
A(B0 D+X-light )
Acp~ r
sin(2+)sin(mt)
D+X-
F. Couderc - Moriond QCD 2005
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B B D Dss+ + XXlightlight – – MotivationsMotivations
sin(2) from CP violation in : B 0 D+ X-light decays
with X-light - , a0
- , a2- but this needs r
( )
CKM allowed
B0 B 0
B 0
r A(B Ds
+ Xlight )
A(B0 D+X-light )
s s
s
less suppressedno CKM allowed background
Trick:Use SU(3) flavor symmetry
F. Couderc - Moriond QCD 2005
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Prediction: B(B0 Ds+ -)=(1.60.3 0.2)10-5
B(B+ Ds+ 0) 0.9 10-5
B(B+ Ds+ 0) < 2 10-4 @ 90% CL (CLEO)
XXlight light 00: B: B++ D Dss++0 0 decaydecay
r = 0.02r
Hint of signal but not significant
Upper Limit @ 90% CL:
B(B+ Ds+ 0) < 2.8 10-5
L = 124 106 BB pairs
Nsig = 12.8
Npeak = 5.4 ± 2.6
F. Couderc - Moriond QCD 2005
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XXlight light aa--0(2) 0(2) : B: B00DDss
++aa--0(2)0(2)
decaydecayDue to fa0(2) CKM allowed and CKM suppressed mediated process have same order of magnitude assuming factorization
B(a-0(2) - ) 100 (15)
%
1
r
fa0 , fa2 small
a0(2)-
× fa0(2) CKM allowed
a0(2)-
CKM suppressed
But D+ [heavy meson] emitted by the W*. Does factorization still hold ?
L = 230 106 BB pairs
B / evts Nsig Nbkg
Ds+a-
03.1+2.9
-
2.3
3.3 0.7
Ds+a-
20.8+1.4
-
0.8
0.4 0.2
B(B0 Ds+ a0
-) < 4.0 10-
5
B(B0 Ds+ a2
-) < 25 10-5
Test CKM suppressed predictions B0 Ds+ a0(2)
-
Btheo(B0 Ds+ a0(2)
- ) 7.3 (1.5) 10-
5
Data inconsistent with factorization prediction
PRELIMINARY
PRELIMINARY
F. Couderc - Moriond QCD 2005
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• not yet observed
• possible large CP asym.
• compare with B0 K+-
B+K+0
BB++ K K*+*+0 0 (K(K+ + 00))0 0 decaydecay
Direct CP violation
Motivations: State of the art: (10-6)• CLEO : B < 31
• factorization: B = 3.3
• SU(3): B = (15-22)
• Charming penguins : B = 8.4
L = 232 106 BB pairs
Unbinned maximum likelihood fit including mES, E,
mK* and a Neural Network (for bkg discrimination) :
Nsig = 88.5 25.7
B = (6.92.01.3)10-6
S = 4.1
= 0.040.290.05
continuum
continuum + BB background
fit projection on
fit projection on
Signal enriched
Signal enriched
PRELIMINARY
PRELIMINARY
F. Couderc - Moriond QCD 2005
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BB+ + ++ & & ’’+ + and others…and others…• process via bu tree (CKM-suppressed) and bs penguins
• B0K0; B0; B++ and B+’+ previously unobserved
• some of them could have large CP asymmetry (measure of )
• test of QCD factorization or SU(3) flavor symmetry
Fit projection on mES
L = 232 106 BB pairs
Signal enriched
Branching ratios in good agreement with theory (Nucl.Phys. B675, 333; Nucl.Phys. B609, 469; PRD69, 074002; PRD68 074012; PRD69, 034001; PRD70, 034020)
No CP asymmetry observed
PRELIMINARY
PRELIMINARY
F. Couderc - Moriond QCD 2005
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non CP related analysisnon CP related analysis
F. Couderc - Moriond QCD 2005
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BB00 D Dss*+ *+ DD*-*- decays and decays and BB ( (DDss))
22 )()( ** pppEEEmDBDbeammiss Mmiss
B(B0 Ds*+ D*-) = (1.880.090.17)
%
NDs= 7488 342
L = 123 106 BB pairs
0BD
0D
SD
)( SD
SKK
KK
,
,, 0
reconstructed
not reconstructed
Missing mass for Ds
Nsig = 212 19
Npeak = 35 6
B(B0 Ds*+ D*-) B(Ds
- -) = (8.81 0.86stat) 10-4 %
Ds reconstructed in -
B(Ds- -) =
(4.81 0.52 0.38) %PDG04 : 3.6 0.9
%
PRELIMINARY
PRELIMINARY
hep-ex/0502041
F. Couderc - Moriond QCD 2005
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Search forSearch for B B++ D D(*)+(*)+KK00 decay (1)decay (1)Motivations: pure annihilation diagram never measured in B+ decays.
• B suppressed by (fB/mB)2 0.002 compared to tree spectator diagram : in this case Btheo O(10-8)
• could be enhanced by rescattering Btheo O(10-5)
• experimental limit: B(B+ D*+ K0) < 9.5 10-5 (CLEO)
F. Couderc - Moriond QCD 2005
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Search forSearch for B B++ D D(*)+(*)+KK00 decay (2)decay (2)
From a fit to data
Evaluated with MC
Results consistent with background fluctuation
B(B+ D+ K0) < 0.5 10-
5
B(B+ D*+ K0) < 0.9 10-5
Upper Limit @ 90% CL:
L = 226 106 BB pairs
PRELIMINARY
PRELIMINARY
F. Couderc - Moriond QCD 2005
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BB J/ J/ D D decay – intrinsic charm (1)decay – intrinsic charm (1)
J/
Effect also reported by CLEO
Hypothesis : intrinsic charm in B mesons, excess BJ/ D()? Btheo 10-4
against 10-8 – 10-7 in perturbative QCD for J/ D
B J/ D < 5.2 10-5 @ 90 % CL (BABAR hep-ex/0406022)
J/ D(*) ? J/ K(*) (BABAR PRD67, 032002)
points : data
histogram : prediction from
simulation (dotted line) and NRQCD
(dashed line)
F. Couderc - Moriond QCD 2005
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BB J/ J/ D D decay – intrinsic charm (2)decay – intrinsic charm (2)
No significant signal coming
from resonant KUpper Limit @ 90% CL:
B+ B0
B(B+J/ D+)< 6.2 10-5
B(B0J/ D 0)< 0.64 10-5
K mass
J/ K
L = 124 106 BB pairs
PRELIMINARY
PRELIMINARY
With cut on the K mass
By product of J/ K* (K) analysis : D reconstructed in Khep-ex/0503021
F. Couderc - Moriond QCD 2005
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(e+e- cc c0X) B(c
0
-+) = 388 39 41 fb
cc00 productionproduction
c0 produced in both e+e- bb (B mesons) and e+e- ccStudy of efficiency-corrected p*(c
0) in the e+e- c.m. frame
cc
BBB(B c
0X) B(c
0 -+) = (2.110.190.25)
10-4
p*(c0) < 1.2 GeV implies production with
a high mass particle (mass > 2.0 GeV/c2) which could be in part due to b ccs decays. (see also BABAR PRD70, 091106(RC),
indirect observation)
L = 116 fb-1
PRELIMINARY
PRELIMINARY
F. Couderc - Moriond QCD 2005
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ConclusionConclusionLot of new or updated results from BABAR:
• prepare the future of CP violation analysis by measuring branching ratios (B+(+-0)DK+, B+K*+0, B0Ds
+a-0(2), BX)
and/or requested quantities (r obtained with B Ds+ Xlight decays).
• Factorization : OK in B X decays (+SU(3) flavor symmetry)
OK in B0 Ds+ a-
0 where a heavy particle (Ds) is
emitted .
• New measurement of the Ds branching ratio, improve the
relative error by a factor of 2 compared to the present value.
• Rules out the hypothesis of intrinsic charm in B mesons with upper limits on B J/ D and B J/ D.
• Study of the c0 production in B decay : could be due to b ccs
transition.