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Luca Lista L.Lista INFN Sezione di Napoli Rare and Hadronic B decays in B A B AR
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Luca Lista Outline Charmonium decays Inclusive Exclusive J/ K* angular analysis Open Charm 2-body hadronic decays quasi 2-body decays Radiative penguin
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Luca Lista Inclusive Charmonium Decays Lepton identification B-counting: Correct by (4S) 1.6% sys. Error 22,700,000 BB events Bremstrahlung-recovery for electrons Background rejection: At least 3 tracks, E tot > 4.5 GeV Ratio of 2 nd to 0 th Fox-Wolfram moment R 2 < 0.5
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Luca Lista Inclusive Charmonium: J/ Inclusive branching ratio: Br(B J/ X) = (1.044 0.013 0.028) 10 -2 Br(B J/ X dir.) = (0.789 0.010 0.034) 10 -2 J/ momentum distribution measured Y(4S) system = B system 250 MeV Polarization -0.424 0.023 (-1 = longitudinal) Signal from continuum subtracted ( …) p* J/ < 2 GeV/c J/ l l , l= e,
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Luca Lista First observation of J/ production in continuum Rejection of BB (p*>2 GeV/c) Rejection of ISR (N tracks, E tot, R 2 ) Angular distribution: 1+A cos 2 * A (all E*) = 0.25 0.19 A (p*>3.5 GeV) = 0.62 0.39 Color singles: A –0.8, 2.8 pb NDQCD (c.o): 0.6<A<1.0, 0.8 pb J/ production in continuum moderesonancep* cut (GeV/c)yield on>2 879 52 eeon>2 799 62 off- 156 25 eeoff- 121 26 Not a B decay, but a new BaBar result…
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Luca Lista Inclusive Charmonium: (2S) p* < 1.6 GeV/c (2S) l l , J/ Br( B (2S) X ) = (0.275 0.020 0.029) 10 -2 (2S) l l branching ratio Assuming PDG values for (2S) J/
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Luca Lista Inclusive Charmonium: c Br(B c1 X) = (0.378 0.034 0.026) 10 -2 Br(B c1 X dir.) = (0.353 0.034 0.024) 10 -2 Br(B c2 X) = (0.137 0.058 0.012) 10 -2 < 0.21 10 -2 @ 90% C.L. c2 (?)
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Luca Lista Exclusive decays Several CP channels sin2 Direct CP asymmetry Kinematics selection: Energy substituted mass Independent on particle mass hypotheses Energy difference in the center of mass Example: B D 0 m ES (GeV/c 2 ) E (GeV)
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Luca Lista B J/ K 0 S
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Luca Lista B J/ K 0 L KL reconstructed as neutral deposit in the IFR or E.M. Calorimeter 1.4 < p* J/ < 2.0 GeV/c No momentum measurement E is measured assuming the m B mass constraint
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Luca Lista Selected channels First observation
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Luca Lista Branching rations results Mode Br ( 10 -4 ) B 0 J/ 0 0.2 0.06 0.03 B 0 J/ K* 0 12.4 0.5 0.8 B + J/ K* 13.7 0.9 1.1 B + J/ K 10.0 0.3 0.5 B 0 J/ K K L 6.8 0.8 0.8 B 0 J/ K K S 0 0 9.6 1.5 0.7 B 0 J/ K K S + 8.3 0.5 0.6 B 0 c1 K* 4.8 1.5 0.9 B + c1 K + 5.1 1.4 1.3 B + (2S)K + 6.1 0.5 0.8 B 0 (2S)K 0 6.5 1.0 1.1
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Luca Lista BaBar compared to PDG 2000
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Luca Lista J/ + / J/ K + Cabibbo and color suppressed tree diagram possible CP asymmetry from penguin contribution Unbinned maximum likelihood fit based on kinematical variables: Br(B + J/ K )/(B + J/ ) =(3.91 0.78 0.19) 10 -2 ( 5.2 2.4 ) % ( 5.0 0.1 ) % +1.9 1.7 ( 5.1 1.4 ) %
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Luca Lista J/ K* angular analysis Channels with 0 Channels without 0 f (cos tr, cos K*, tr ) = f 1 |A 0 | 2 + f 2 |A || | 2 + f 3 |A | 2 f 4 Im(A || * A ) + f 5 Re (A 0 * A || ) + f 6 Im (A 0 * A ) J/ rest frame K* decay plane |A | 2 + |A || | 2 + |A 0 | 2 = 1
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Luca Lista J/ K* angular analysis |A | 2 = 0.160 0.032 0.014 CP odd, P wave |A || | 2 = 0.243 0.034 0.017 CP even, S+D wave |A 0 | 2 = 0.597 0.028 0.024 CP even, S+D wave = arg(A /A 0 )= 0.17 0.16 0.07 || = arg(A || /A 0 )=2.50 0.20 0.08 CP asymmetry dilution factor: D = 1 – 2 |A | 2 = 0.68 0.10 (a) Raw measurement (b) Acceptance correction (c) “ “ + m ES fit (d) “ “ + (Self) Feed Across Indication of FSI
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Luca Lista B D* , D* May exhibit small CP asymmetries Potential for sin(2 + ) and Reconstruct the decay chains: B reconstruction efficiencies estimated with MC
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Luca Lista Br (B D* + ) = (2.9 ± 0.3 ± 0.3 ) 10 -3 PDG: (2.76 ± 0.21) 10 -3 B D*
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Luca Lista Br (B D* + ) = (11.2 ± 1.1 ± 2.5 ) 10 - 3 PDG: (6.8 ± 3.4) 10 -3 B D*
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Luca Lista B D* + D* Independent measurement of sin2 D* D 0, D 0 D 0 K , K , K , K S D K , K S , K K B decays with two 0 are not used High background, low branching fraction Many possible combinations in the same event. Chosen the one which minimizes:
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Luca Lista B D* + D* Br(B D* + D* - ) = (8.0 1.6 1.2) 10 -4
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Luca Lista B D*D ( * ) K b ccs transition D *+ D 0 + ; D *0 D 0 0 D *0 D 0 D 0 K - +, D 0 K - + 0 D 0 K - + - + ; D + K - + + ; Br(B D* D 0 K ) = (0.28 0.07 0.05) 10 -2 Br(B D* D* K ) = (0.68 0.17 0.17) 10 -2 Br(B D* D* K ) = (0.34 0.16 0.11) 10 -2 First observation of non-charmonium color suppressed mode B 0 (all modes) N S = 180 21 B + (all modes) N S = 117 15 B D* D* K N S = 8.2 3.5
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Luca Lista Charmless Hadronic Decays Physics motivations b u d(s) V ub V ud(s) B0B0 { } } } (K ) dd u b B0B0 { d u d(s) } } } (K ) d u t WW WW V tb V td(s) Cabibbo suppressed Penguin diagram Significant penguin contribution Direct CP violation studies Measurement of from time-dependent asymmetry + isospin analysis Possible field for new physics…
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Luca Lista Identifying K and Particle identification in the DIRC D* + D 0, D 0 K - + control sample
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Luca Lista Background Rejection Continuum events rejection Fisher discriminator on event shape Thrust axis (B vs rest of event) Background control samples E sidebands Off-resonance data D* + D 0, D 0 K + control sample signal D 0 + on reson. m ES <5.26 background signal
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Luca Lista Two Body Charged Modes B h h KK KKKK ModeYeld, significance Branching ratio KK 169 17 +12 -17, 15.8 (16.7 1.6 +1.2 -1.7 ) 10 –6 41 10 7, 4.7 (4.1 1.0 0.7) 10 –6 KKKK 8.2 +7.8 –6.4 3.3, 1.3 <2.5 10 –6 (90%C.L.) UML Fit results Cut based selection
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Luca Lista Two Body Charged + Neutral Modes B 0 h 0+0+ 0K+0K+ ModeYeld, significance Branching ratio 37 +15 -13, 3.4 (5.1 +2.0 -1.8 0.8) 10 –6 KK 75 +14 -13, 8.0 (10.8 +2.1 -1.9 +1.0 -1.2 ) 10 –6 UML Fit results Cut based projections
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Luca Lista BK0h+, K00BK0h+, K00BK0h+, K00BK0h+, K00 K0+K0+ K0K+K0K+ K00K00 Cut based projections ModeYield, significance Branching ratio K0K0 59 +11 -10, 9.8 (18.2 +3.3 -3.0 +1.6 -2.0 ) 10 –6 K0KK0K 0 (< 8), 0 <2.6 10 –6 (90%C.L.) K00K00 17.9 +6.8 -5.8, 4.5 (8.2 +3.1 -2.7 +1.1 -1.2 ) 10 –6
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Luca Lista Charge Asymmetries K A = -0.19 0.10 0.03 [ -0.35, -0.03 ], 90%C.L. K A = 0.00 0.18 0.04 [ -0.30, +0.30 ], 90%C.L. K A = -0.21 0.18 0.03 [ -0.51, +0.09 ], 90%C.L. All asymmetries compatible with 0 within current errors
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Luca Lista B + h + < 24 10 -6 ( 90% C.L. ) B 0 K 0 < 14 10 -6 B + K + ( 62 18 8 ) 10 -6 B 0 K 0 < 112 10 -6 B 0 K* 0 < 28 10 -6 B + 0 K + < 39 10 -6 B + 0 + < 39 10 -6 B + K + < 54 10 -6 B + + < 22 10 -6 B 0 ( 49 13 +6 -5 ) 10 -6 Quasi 2-body and 3-body decays
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Luca Lista B K, B K* Penguin dominated Measure of sin2 B + K + = (7.7 +1.6 -1.4 0.8) 10 -6 B 0 K 0 = (8.1 +3.1 -2.5 0.8) 10 -6 B + K* + = (9.7 +4.2 -3.4 1.7) 10 -6 B 0 K* 0 = (8.6 +2.8 -2.4 1.1) 10 -6 B 0 < 1.4 10 -6 (90% C.L.)
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Luca Lista B K* Signal: B 0 K* 0 , K* 0 K + - Backgrounds: e + e - qq e + e - qq X 0 Sensitive to top quark couplings CKM matrix elements V td,V ts Sensitive to New Physics SUSY, Charged Higgs No CP asymmetry in the Standard Model Possible sources beyond SM
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Luca Lista B K* : yield and branching ratio N signal = 139.2 13.1 events Br(B 0 K *0 ) = (4.39 0.41) 10 -5 Br(B K + e + e - ) < 12.8 10 -6 Br(B K + + - ) < 8.3 10 -6 Br(B K* 0 e + e - ) < 24.7 10 -6 Br(B K* 0 + - ) < 25.7 10 -6 (90% C.L.)
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Luca Lista B K* : CP asymmetry K * 0 - K* 0 K N(B 0 ) = 72.1 9.4 events N(B 0 ) = 67.2 9.1 events A CP = -0.035 0.09
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Luca Lista b s , B Semi-exclusive study Sum of exclusive modes K+n (n=1,2,3) B(B 0 ) < 1.94 x 10 -6 90% C.L. PDG: B(B 0 ) < 3.9 x 10 -5 90% C.L. (from L3) m ES for 0.6 <m had < 2.0 GeV 668 53 events PRELIMINARY
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Luca Lista Conclusions Many branching ratios have been measured in BaBar Some are newly observed signals Potential for more CP violation studies More statistics will permit to measure CP asymmetries Stay tuned!
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