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V.Tisserand, LAPP-Annecy (IN 2 P 3 /France), on behalf of the B A B AR collaboration. Aachen (Germany), July 17 th -23 rd 2003. Charmed B hadrons with B A B AR Testing factorization with color-suppression: B ̅ 0 D ( * )0 [ 0, , , ’ ] Modes for reaching in the future (CP violation): B - D 0 (CP) K - and D* 0 K* - Understanding charm multiplicity: B D ̅ ( * ) D ( * ) K
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Testing factorization with color-suppression D ( * )+ -,--,- c dd b dd d uu B0B0 Color-allowed: B0B0 0,,,’,00,,,’,0 D ( * )0 c uu d dd b dd Color-suppressed: Naïve factorization model: h light meson and D ( * ) meson hadronize independently and predicts: B ( B 0 D ( * )0 h 0 ) ( 0.3 1.7 ) 10 -4 B ( 3 8 ) 10 -3 B (1/3)² 10 - 4 A ( B 0 D ( * ) + h - ) a 1 A ( B 0 D ( * )0 h 0 ) a 2 a i universal QCD Wilson coefficients: |a 2 /a 1 | ( 0.2 0.3 )/ 1.1~ 0.25 Factorization fails if final state interactions (FSI) produce important constructive strong interferences and re-scattering A (color-suppressed) (a 2 and a 1 ), see isospin amplitudes triangle (eg.):
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signal yields and combinatorial bckgd from m ES unbinned ML fit. peaking bckgd from MC. Color-suppressed B 0 D ( * )0 h 0 : signal events yields (1) 88.8 10 6 BB ̅ pairs 81.9 /fb Signatures: D* 0 D 0 0, D 0 K - +, K - + 0, and K - + - +. m ES ~m B = beam energy substituted mass D00D00 D* 0 0 487 34 sig. e vts 88.4 12.0 sig.e vts D 0 ( ) 173 20 sig.e vts D 0 ( ) 74.4 11.6 sig.e vts D 0 ( ) 198 18 sig. e vts
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D 0 ’ ( ) 26.6 6.0 sig.e vts D* 0 70.4 12.1 sig. e vts D* 0 ’ ( ) 4.0 2.2 sig.e vts D* 0 ( ) 39.5 7.2 sig.e vts New modes not measured so far by Belle’02 or CLEO’02, nor by B A B AR ’02 ! 88.8 10 6 BB ̅ pairs ~81.9 /fb Color-suppressed B 0 D ( * )0 h 0 : signal events yields (2)
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88.8 10 6 BB ̅ pairs 81.9 /fb B for Color-suppressed B 0 D ( * )0 [ 0, , , ’] 14.3 7.6 8.9 6.2 11.3 5.5 10.7 6.1 6.3 3.0 D 0 0 D* 0 0 D 0 D* 0 D 0 D* 0 D 0 ’ D* 0 ’ ( ) ( ) ( combination ) 2.92 0.20 0.33 2.90 0.38 0.48 2.37 0.26 0.27 2.79 0.43 0.41 2.49 0.22 0.30 2.63 0.44 0.42 2.96 0.26 0.40 4.22 0.68 0.88 1.68 0.38 0.22 1.29 0.71 0.19 < 2.6 (90 % CL) B 0 B ( 10 -4 ) ( stat syst) S/ S+B B much larger than what naïve factorization predicts: 2.5 7.5 (Neubert and Stech’98). better agreement with models including FSIs (Chua et al.’02). New modes not yet in PDG ! 7 color-suppressed modes precisely meas. with statistic. signif: > 5.5 and 1 with 3 Preliminary results
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extract CKM from interference of charged B decaying to common final states: ( b c ) and ( b u ) * Motivations for B - D ( * )0 (CP) K ( * )- * Atwood, Dunietz, Gronau, Jang, Ko, London, Rosner, Soni, Wyler … V us V* cs V* us V cb V ub (=A 3 e -i ) B-B- B-B- D ( * )0 D ( * )0 K ( * )- CP violation effect expected to be small as the amplitude is: Cabibbo-suppressed: V ub /(V cb V* us )~ 35% Color-suppressed: |a 2 /a 1 |~ 0.25, but maybe not so much ! it’s a long way until !: statistically very challenging (>500/fb ?)
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61 10 6 BB ̅ pairs 56 /fb So approx.: B (B - → D 0 K - ) = 4.4 10 -4 R reduces the syst. errors (weighted result over 3 D 0 modes) * (s d): sin²( c ) R = (8.31 0.35 0.20)% * B ( B - D 0 ( K ,K 0,K 3 ) K - ) Preliminary results Signal extracted from an unbinned ML fit to: E, m ES and DIRC (K/ ID) Energy difference with Kaon mass hypothesis for fast track: K-+K-+ no PID on K - K E K (GeV) B-D0 h-B-D0 h- K-+-+K-+-+ K-+K-+ Tight PID on K - K-+0K-+0 E K (GeV)
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D 0 CP + - with tight PID: K - * E K (GeV) 88.8 10 6 BB ̅ pairs 81.8 /fb * and D 0 ( K ) resonant bckgds: mD 0 instead of m ES in the ML fit. D 0 CP K + K - with tight PID: K - B - D 0 CP=+1 ( K - K +, + - ) K - look for direct CP violation where the D 0 decays to CP eigenstates (B + B - asymmetry ?): direct CPV not seen yet ! =(0.07 0.17 0.06) A cp = = (8.8 1.6 0.5)% Preliminary results
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B ( B - D* 0 K* - ) and polarization 85.9 10 6 BB ̅ pairs 79.1 /fb Vector-Vector decay: MC acceptance very sensitive to the longitudinal polarization fraction, our measurement : L / = (0.86 0.06 (stat) 0.03 (syst) ) predicted by models based on factorization and HQET (see CLEO hep-exp0301028) Signatures: D* 0 ( D 0 0,D 0 ), K* - ( K 0 s - ), and D 0 ( K - +,K - + 0,K 3 ). Signal PDF and MC eff’cy calibrated with D* 0 - high purity ctrl samp. (~ 50 /fb 4500 evts) All D* 0 decays 121 15 sig.evts ( 6.8 3.4 peaking bckgd) m ES (GeV/c²) B ( B - D* 0 K* - ) = (8.0 1.0 (stat) 1.2 (syst) ) 10 -4 * * (s d): sin²( c ). B ( B - D* 0 - ) Preliminary results
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The B (semi-lepto.)/n C puzzle in B decays B (semi-lepto.) % Inclusive measurement Exclusive measurement Theory ( 10.6 10.9 %: ALEPH, CLEO, B A B AR … ) nCnC Theory is unable to describe: low n c value and low B (semi-lepto.). (eg.: Bigi et al ’94, Neubert and Sachrajda’97) n c : charm multiplicity in B decays Inclusive: LEP+SLD+wrong sign D CLEO ’ 98 : B (B DX) WS =( 7.9 ± 2.2 )% 2 experimental methods: Exclusive: B Charm hadrons includes hadronization of b c c ̅ s that has been supposed to be dominated by B D s ( * ) X decay: not enough !
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understanding hadronization of b c c ̅ s with B D ̅ (*) D ( * ) K (1) B D ̅ (*) D ( * ) K can significantly contribute to B ( b c c ̅ s ) and to wrong sign D ( * ) ! (Buchalla, Dunietz, and Yamamoto’95) 22 exclusive modes: some already reco’ed by ALEPH, CLEO, Belle, and BABAR. external W B B wrong sign D(*)D(*) D(*)D(*) D(*)D(*) D(*)D(*) K K (+) interference internal W
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82.3 10 6 BB ̅ pairs 75.9 /fb ( 3.9 0.2 (stat) 0.6 (stat)) % very precise CLEO ’ 98 (ws D): B (B DX)=( 7.9 ± 2.2 )% not all wrong sign Ds B (B 0 D ̅ (*) D ( * ) K )=( 4.3 0.3 (stat) 0.6 (syst) )% B (B + D ̅ (*) D ( * ) K )=( 3.5 0.3 (stat) 0.5 (syst) )% hep-ex/ 0305003 submitted to PRD b c c ̅ s with B D ̅ (*) D ( * ) K (2) E (GeV) m ES (GeV/c²) Side-band B0B0 B+B+ All the 22 possible modes studied: 11 sub-decay modes with > 4 823 57 970 65
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not really significant yet UL @ 90% CL from individual D ̅ (*) modes on B (D ̅ (*) D (*) K D s1,2 ): 3-12% s s s s P-waves: L=1, j s =3/2 Narrow states J P =1 + : D s1 ( 2536 ) + D* 0 K + J P =2 + : D s2 ( 2573 ) + D 0 K + * fixed in the fit from cc ̅ data: 18/fb m=m(D ( * )0 K + )-m(D ( * )0 ) (GeV/c²) B D ̅ (*) (D s1 ( 2536 ) + D* 0 K + ) B D ̅ (*) (D s2 ( 2573 ) + D 0 K + ) (764 50) B D ̅ (*) D* 0 K + cands. used ( m= 527.9, Gauss = 3.5 ) * MeV/c² (604 54) B D ̅ (*) D 0 K + cands. used ( m= 708, Gauss = 6 ) * MeV/c² B D ̅ (*) D ( * ) K intermediate D** s states: D s (J=1,2) ( 2536,2573 ) +
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Broad D sJ L=1, j s =1/2 searched in D ̅ (*) D ( * ) K decays. assume (broad: few 100 MeV): mass D sJ > or mass (D ( * ) + K) Intermediate broad D** s states D s(J=0,1) (??) use high rate/purity B 0 D *- D *0 K + m²(D* 0 K + ) (GeV²/c 4 ) DATA m ² (D* - D* 0 ) (GeV²/c 4 ) MC phase space model Dalitz plot: DATA /MC phase space large density at low values of m²(D* 0 K + ). m ES (GeV/c²) But also: recent discoveries on narrow D* s0 +(2317) and D* s1 +(2463) below D(*)K mass threshold ! ( BABAR, CLEO, and Belle).
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ConclusionsConclusions New precise B measurements for B 0 D ( * )0 [ 0, , , ’ ] Color-suppressed decays in the range: ( 1.3 4.3 ) 10 -4. On the road to measurement: D 0 K - : R(K/ ) ~ 8 9 % and no direct CPV found in D 0 ( ,KK) CP=+1 modes. D* 0 K* - : very precise B = (8.0 1.0 (stat) 1.2 (syst) ) 10 -4 measurement and fraction of longit. polariz.: L / ~ 90 %. n C in B decays + complete B D ̅ (*) D ( * ) K study: 1/3 B ( B D s X ) and explains ~1/2 inclusive wrong signs D (need a more precise measurement there). searched for intermediate L=1 broad and narrow D s ** states.
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