Hadronic B and D decays studies at B A B AR

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


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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


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CP related analysisCP related analysis


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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


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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-


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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


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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


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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 ?


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


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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


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


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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


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


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non CP related analysisnon CP related analysis


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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


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


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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)


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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:


PRELIMINARY

PRELIMINARY


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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)


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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


PRELIMINARY

PRELIMINARY

With cut on the K mass

By product of J/ K* (K) analysis : D reconstructed in Khep-ex/0503021


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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


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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.

Hadronic B and D decays studies at B A B AR

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