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1 Disclaimer This talk is not for B physics experts. Taipei101 If you did it, you may check e-mails during my talk. B0B0 B0B0
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2 ( and 3 ( ) Masashi Hazumi (KEK) 3 rd International Conference on Flavor Physics (ICFP2005), October 3-8, 2005 1 “beam” 2 “banana” 3 “fan”
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3 Motivation for 2 and 3 measurements Overconstrain the CKM unitarity triangle –important test of Kobayashi-Maskawa mechanism of CP violation –one of the main physics goals of BaBar and Belle Overconstrain the CKM unitarity triangle –important test of Kobayashi-Maskawa mechanism of CP violation –one of the main physics goals of BaBar and Belle 1 “beam” 2 “banana” 3 “fan”
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4 Principle of measurement 2 from time-dependent CP asymmetries 3 from direct CP asymmetries 1 “beam” 2 “banana” 3 “fan” (other methods exist but are not competitive)
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5 Methods Interestingly, at present best results on 2 and 3 are obtained by methods proposed after B factories started taking data. In reality, you need two diagrams with different weak phases (CP-odd phases) and strong phases (CP-even phases) two amplitudes with similar size ( |A 1 /A 2 | = r > O(0.1) ) precise measurements (knowledge) on and r sufficient signal yields with good (tolerable) background level A 1 /A 2 =|A 1 /A 2 |exp(i )exp(i ) CP |A 1 /A 2 |exp( i )exp(i )
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6 Mixing-induced CP violation (CPV) and 2 ( ) 11 33 22 V ud V * ub V td V * tb V cd V * cb B0B0 d b – d – bt – t B0B0 – V * tb V td V * tb V td Mixing diagramDecay diagram (tree) B0B0 b – d d u – d – u // // V ud V * ub
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7 Mixing-induced CP violation (CPV) and 2 ( ) B 0 B 0 ( B 0 E (GeV) Events/(0.02GeV) 666±43 signals from 275 million BB pairs Small |V ub | = (4.38 0.19 0.27 ) 10 3 measurements still limited by statistics B0B0 b – d d u – d – u // // V ud V * ub
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8 Mixing-induced CP violation (CPV) and 2 ( ) B 0 B 0 ( B 0 Small |V ub | = (4.38 0.19 0.27 ) 10 3 measurements still limited by statistics 617±52 signals from 232 million BB pairs signal-enhanced region B0B0 b – d d u – d – u // // V ud V * ub
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9 made by H. Miyake Time-dependent CP violation in B 0 ( A = C ) (CP = +1) Mixing-induced CPVDirect CPV With the tree diagram only S = sin2 2 A = 0
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10 Tough ( ) bananas: penguin pollution Compelling evidence for direct CPV Large penguin diagram (P) ~ Tree diagram (T) Large strong phase difference between P and T B 0d0d d b d u u W g ++ -- V td V * tb t d A S 4.0 direct CPV 4.0 direct CPV
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11 Isospin analysis: flavor SU(2) symmetry Model-independent (symmetry-dependent) method SU(2) breaking effect well below present statistical errors
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12 2 ( ) from B inputs B ( + 0 ) = (5.5 0.6) B ( + - ) = (5.0 0.4) 10 -6 B ( 0 0 ) = (1.5 0.3) A ( 0 0 ) = +0.28 0.4 S ( + - ) = 0.50 0.12 A ( + - ) = +0.37 0.10 inputs B ( + 0 ) = (5.5 0.6) B ( + - ) = (5.0 0.4) 10 -6 B ( 0 0 ) = (1.5 0.3) A ( 0 0 ) = +0.28 0.4 S ( + - ) = 0.50 0.12 A ( + - ) = +0.37 0.10 larger than expected big impact on 2 determination larger than expected big impact on 2 determination
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13 Isospin analysis with B 0 Even worse on first sight... –Dirty final state: –Mixture of CP = +1 and 1: need to know each fraction (A + +A - )/√2 A || (A + -A - )/√2 A⊥A⊥ A0A0 + + A0A0 A+A+ A-A- +1 1 1 CP vector
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14 B 0 longitudinal polarization from helicity distribution total background f L = 0.951 0.029 0.031 0.033 0.039 f L = 0.978 0.014 0.020 0.028 CP (A + +A - )/√2 A || (A + -A - )/√2 A⊥A⊥ A0A0 + + A0A0 A+A+ A-A- +1 1 1 ~purely CP = +1 ! ~purely CP = +1 !
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15 2 ( ) from B 22 A 00 A +- / 2 squashed triangle small Inputs to isospin analysis B ( + 0 ) = (26 6) B ( + - ) = (26 4) 10 -6 B ( 0 0 ) < 1.1 A ( 0 0 ) = N.A. S ( + - ) = 0.22 0.22 A ( + - ) = 0.02 0.17 Inputs to isospin analysis B ( + 0 ) = (26 6) B ( + - ) = (26 4) 10 -6 B ( 0 0 ) < 1.1 A ( 0 0 ) = N.A. S ( + - ) = 0.22 0.22 A ( + - ) = 0.02 0.17 the best mode now ! 2 = (96 13)º (triangle not closed with present central values)
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16 Time-dependent Dalitz analysis with B 0 A rE to try even more involved analysis s = m( ) 2 s + =m( ) 2 ++ ++ ++ Isospin analysis isolate penguin and restore the simplicity Dalitz analysis accept complication and dare to utilize Breit-Wigner phases Isospin analysis isolate penguin and restore the simplicity Dalitz analysis accept complication and dare to utilize Breit-Wigner phases is for strong/CP-even phase difference. Breit-Wigner phases from . A mplitudes should be large enough for good statistics. similar to r atios between amplitudes Determined by Dalitz fit E xperimentally favored (e.g. high efficiency, small background) Not so great but tolerable Snyder-Quinn 1993
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17 2 = (113 6)º +27 17 2 ( ) from B 0 No discrete ambiguity in 0-180 deg. ! Important in the future.
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18 2 ( ) from B
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19 2 W.A. CKM (indirect) All W.A.
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20 Direct CP violation and 3 ( ) 11 33 22 V ud V * ub V td V * tb V cd V * cb u b u u c s W B +d+d D0D0 V cs V*ubV*ub f COM 3 u b u s u c W B +d+d D0D0 ++ V us V * cb _ f COM 3 B D (*) K (*) Choice of f COM very imporant ! Color suppressedColor allowed
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21 A rE to measure 3 (1) GLW f COM = D CP [PLB 253,483; 265,172(’91)] + - / + - (CP=+1), S 0 / .. (CP= 1) Gronau-London-Wyler 0.01.0 0.01.0 A CP= , R CP= r B, B, 3 need more statistics (four observables, three unknowns) O∆ ∆ O score
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22 A rE to measure 3 (2) ADS f COM = D DCSD Atwood-Dunietz-Soni Not yet observed, but important limit on r B already available Not yet observed, but important limit on r B already available OX ∆ O score [PRL 91,171801(’03)] color suppresed Cabibbo suppresed
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23 A rE to measure 3 (3) Dalitz f COM = Ks OO ∆ O score Giri-Grossman-Soffer-Zupan [PRD 68,054018(’03)] B+:B+: B-:B-: m + =m(K s + ), m =m(K s ) CPV : Asymmetry in Dalitz dist.: r r |A 2 | |A 1 | r = obtain from tagged D 0 (D *+ D 0 + ) sample
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24 Signal yields 232M BB 275M BB D 0 K* D0KD0K D* 0 K [D 0 0 ] 209 signals 58 signals 36 signals 49 signals 90 signals 282 signals [hepex/0504039] [hepex/0411049][hepex/0504013] EE EE EE
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25 Dalitz Plots: D 0 K 232M BB 275M BB B+B+ BB B+B+ BB
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26 3 Fit Results -100 0 100 0 0.1 0.2 0.3 3 (deg) rBrB -100 0 100 0 0.1 0.2 0.3 rBrB 3 (deg) D 0 K* D0KD0K D* 0 K [D 0 0 ] D0KD0K D* 0 K [D 0 0 ] 3 = (68 13 11 model )º +14 15 3 = (67 28 13 11 model )º 3 = (67 28 13 11 model )º [hepex/0507101] [hepex/0411049]
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27 3 ( ) from B D (*) K (*) 3 = (63 )º +15 12
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28 Unitarity Triangle with Angle Measurements 1 = (22 1)º 2 = (99 )º 3 = (63 )º +13 8 +15 12 1 + 2 + 3 = (184 )º +20 14 (naïve sum by the speaker)
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29 All combined ρ = 0.216 ± 0.036 η = 0.342 ± 0.022
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30 Summary Recent remarkable progress in 2 and 3 measurements – Now overconstraining CKM just from angle measurements (i.e. from CP asymmetries alone !) O(10º) achieved using new ideas ! – for 2, DK Dalitz for 3 – Still limited by statistics Improvements in the future guaranteed To compete with the 1 precision, we need – better understanding of hadronic uncertainties SU(2) breaking Dalitz amplitudes, amplitude ratios, etc. – much more data LHCb, Super B factory 1 = (22 1)º 2 = (99 )º 3 = (63 )º +13 8 +15 12
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31 Backup Slides
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34 b u W B 0 ++ VudVud VcbVcb c d D*D* d d b c W B 0 ++ V cd V ub u d D*D* d d (B 0 →D ) ~ 1 + cos( mt) – S sin( mt) (B 0 →D ) ~ 1 + cos( mt) S sin( mt) (B 0 →D ) ~ 1 cos( mt) S sin( mt) (B 0 →D ) ~ 1 cos( mt) S sin( mt) Cabibbo favored Cabibbo suppressed CP S = 2( 1) L R sin(2 1 3 ) : hadronic phase, R = ~0.02 A CF A DCS mixing mixing induced CPV [L=0 (D ), 1(D ) R, not same for D and D sin(2 1 + 3 ): B 0 D (*)+ - TCPV 4 2 [I.Dunietz, PLB 427,179(’98)] B0→B0→ mixing A DCS A CF
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35 t Distributions B 0 D 10.6K cand.(96% purity) B0B0 B0B0 152M BB 232M BB partial reconstruction B0B0 B0B0 D CP Full recon. -10 -5 0 5 10 t(ps) 89.3K signals Good tag Lepton tag background D D [hepex/0504035][PRL 93,031802(04)] D D D
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36 sin(2 1 + 3 ): Summary D* DD DD (c~0 if ~0 or 180 deg.)
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37 Extraction of 3 ? estimated form B (B D s ) [SU(3) symmetry] No significant constraint yet ! R
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