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Sep 11, 2006SLUO Anual Meeting 20061 Search for Super-Penguins: CP Violation in B 0 ->K+K-K 0 D. Dujmic, SLAC For BABAR Collaboration D. Dujmic, SLAC For BABAR Collaboration Special thanks to: G. Cavoto, M. Krishnamurthy, E. Di Marco, M.Pierini, A.Roodman, S.Spanier, J.Thompson SM rules
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Sep 11, 2006SLUO Anual Meeting 20062 CP Violation in SM CKM picture of charged weak currents: But amount of CP violation too small: - observation: - area of unitarity triangle: p=u,c,t q=d’,s’,b’ W ± V pq ? Additional sources of CP violation needed (solely responsible for CPV in SM)
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Sep 11, 2006SLUO Anual Meeting 20063 Search for Super-Penguins Penguin amplitude in SM Virtual, heavy particles can appear in loops - can be relatively large, O(1) - in general not CP-conserving Double-CKM suppression: Loop suppression: Decay rates small BF<7·10 -5 Super-penguin, beyond-SM? Example of SUSY diagram SM rules
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Sep 11, 2006SLUO Anual Meeting 20064 CPV Parameter sin2 B0 K+K-K0 amplitudes: CPAsymmetry: (B0/B0bar tags) ~0 Interference term has different signs for B0/B0bar tags Interference phase only due to B0/B0bar mixing (in SM) IF: same asymmetry for J/ K S and K + K - K S super-penguins exist! K+K-K0 flavor tag e+ e- SM super penguins or
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Sep 11, 2006SLUO Anual Meeting 20065 Estimate of sin2 in K+K-KS From tree-dominated decays B 0 ->J/ K S (SM reference point): (penguin-tree) Experimental average of all penguins Tree Penguin
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Sep 11, 2006SLUO Anual Meeting 20066 Analysis of 3-Body Decay Selection of charm-less 3-body decays is tricky - large background requires usage of several kinematic, event- shape variables in event selection - good particle ID K+K+ KK B0B0 KSKS L L’=L L=even CP(K+K-K S )= + 1 L=odd CP(K+K-K S ) = - 1 *[ CP(KKKS)= - CP(KKKL) ] How to analyze angular momentum composition? CP Violation measurement with additional complication - CP depends on angular momentum L between K+ and K- - (K+ K-)KS can be both CP-even and CP-odd * -sin2 +sin2 -> (2f odd -1) sin2 Dilution if both CP present!!
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Sep 11, 2006SLUO Anual Meeting 20067 CP Content Fractions of P-wave from analysis of angular moments: –0.29 ± 0.03 over whole DP –0.89 ± 0.01 in (1020) region From 624±30 K+K+K- decays From 879±36 K+K-KS( ) decays Need Dalitz plot analysis to measure CP asymmetry BABAR-CONF-06/40 (ICHEP06) previously: - cut >1.1GeV (assume CP-even) - 1.0045<m<1.0345 (assume CP-odd) Fraction of P-wave P-wave strength
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Sep 11, 2006SLUO Anual Meeting 20068 B 0 → K + K - K 0 Isobar Model Charm(onium) contributions: D - K +, D S - K + c0 K 0 K0K0 f 0 (980)K 0 X 0 (1550)K 0 Non- resonant toy Dalitz plot ComponentCP K0K0 odd f 0 (980)K 0 even X 0 (1550)K 0 even Nonresonanteven(90%) odd(10%) c0 K 0 even Use flavor-symmetry to relate BABAR’s K+K+K- Dalitz plot
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Sep 11, 2006SLUO Anual Meeting 20069 Dalitz Plot PDF Measure CP asymmetry in time-dependent Dalitz plot: Five observables: t, ( t), m(K + K - ), cos H, tag flavor B0 amplitude B0bar amplitude CP Violation: Rate difference Phase difference
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Sep 11, 2006SLUO Anual Meeting 200610 … Add All K+K-K0 Final States (1020) “X 0 (1550)” c0 Non-resonant f 0 (980) K+K-K L K+K-K S ( ) K+K-K S ( ) Add K+K-K S (K S ) and K+K-K L All channels use same Dalitz plot model! ~1500 signal events 138 ± 17 499 ± 52 879 ± 36
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Sep 11, 2006SLUO Anual Meeting 200611 Average CP-Asymmetry Combine KKKS+-, KKKS00, and KKKL Assume same CPV parameters for all KKK0 KKKS+- alone: ComponentFraction (%) K0K0 12.9±1.3 f 0 (980)K 0 22.3±8.9 X 0 (1550)K 0 4.1±1.8 Nonresonant91±19 c0 K 0 2.8±0.8 D - K +, D S - K + 4.9±1.1 SM: A CP =0 =0.370
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Sep 11, 2006SLUO Anual Meeting 200612 Measurement of Assume final state is mixture of CP-eigenstates (partial waves) both real and imaginary b/c of CP-even, -odd interferences (->2 ) real in Q2B analyses (->sin2 ) 4.6 eff eff eff
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Sep 11, 2006SLUO Anual Meeting 200613 CPV in Low K+K- Mass Resonant fractions for m(K+K-)<1.1GeV (1020) K 0 57% f 0 (980) K 0 34% Non-res13% Low-K+K- mass fit for CPV parameters in K 0 and f 0 K 0 to reduce dependence on Dalitz plot model K 0 theoretically very clean (sin2 )~ O(1%) Fix S-wave, float isobar parameters for P- wave KKKs+-252 ± 19 KKKs0035 ± 9 KKKL195 ± 33
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Sep 11, 2006SLUO Anual Meeting 200614 CPV in Low K+K- Mass Combined KKKS+-, KKKS00, and KKKL cross-check with Q2B analysis syst. errors dominated by Dalitz plot model consistent with SM, Belle SM: A CP =0 =0.370 KSKS f0KSf0KS CPV measurements in f 0 Ks and Ks correlated (one background for the other) asymmetry plot ±15MeV under
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Sep 11, 2006SLUO Anual Meeting 200615 Summary Time-dependent Dalitz plot analysis opens new possibilities in study of penguin decays: - measurement of asymmetry angle (instead of sine of the angle) - removes dilution for final states with opposite CP - model uncertainties included in fit BABAR ( sin2 )Belle (sin2 ) KKK 0 0.661 ±0.12 ± 0.06 (all KKK 0 ) 0.68 ±0.15 ±0.03 +0.21 −0.13 (excluding K S, KKK S only) K0K0 0.12 ±0.31 ±0.10 0.50 ±0.21 ±0.06 f 0 (KK)K 0 0.31± 0.32 ± 0.07No result (f 0 K + K - ) Lower sin2 than expected consistent with trend seen in other analyses CPV results from penguin decays still intriguing, but need to work harder to observe new phenomena
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Sep 11, 2006SLUO Anual Meeting 200616 More Slides
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Sep 11, 2006SLUO Anual Meeting 200617 Angular Moments - Decay rate in terms of moments of Legendre polynomials: - Model-independent approach to extract CP content [BABAR, PRD71,091102] - Assume S and P-waves decaying into K + K - S-wave P-wave - Moments computed using sPlots [Pivk, Le Diberder, Nucl.Inst.Meth. A555] - Fraction of P-wave: K+K+ KK KSKS (angular momentum conservation) K + K - CMS
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Sep 11, 2006SLUO Anual Meeting 200618 BABAR/Belle 2006: B 0 KKK S Belle’s estimate (±10MeV): K+K+K- Dalitz (140 fb-1) ~2.75±0.14% ignores f0(980) Belle’s helicity plot (±10MeV under mass) [Hazumi ICHEP06 talk] BABAR B0 K+K-K0 (347MBB) (bkg substracted) hep-ex/0607112 B+ K+K+K- (230MBB) PRD72,032003(2006) Belle non-zero yield below and above peak! Estimates from BABAR results (±10MeV): K+K+K- moments (347MBB): ~8±1% K+K-K0 Dalitz (347MBB) and K+K+K- Dalitz (230MBB): f0K~10±3%, NR~3±1% -> 13±3% Belle’s fitting range Old BABAR fitting range
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Sep 11, 2006SLUO Anual Meeting 200619 Dalitz Plot Isobar Model Blatt-Weisskopf form factorsBreit-WignerAngular correlations i j k {ij} res i j k ∑ res Resonant amplitude: “Non-resonant” B B Single channel BW Coupled channel BW (Flatté) Decay amplitude = “resonant”
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