1 / 19

Search for Super-Penguins: CP Violation in B 0 ->K+K-K 0

Search for Super-Penguins: CP Violation in B 0 ->K+K-K 0. SM rules. D. Dujmic, SLAC For BABAR Collaboration. Special thanks to: G. Cavoto, M. Krishnamurthy, E. Di Marco, M.Pierini, A.Roodman, S.Spanier, J.Thompson. p=u,c,t. W ±. V pq. ?. q=d’,s’,b’. CP Violation in SM.

camden-scott
Télécharger la présentation

Search for Super-Penguins: CP Violation in B 0 ->K+K-K 0

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Search for Super-Penguins:CP Violation in B0->K+K-K0 SM rules D. Dujmic, SLAC For BABAR Collaboration Special thanks to: G. Cavoto, M. Krishnamurthy, E. Di Marco, M.Pierini, A.Roodman, S.Spanier, J.Thompson SLUO Anual Meeting 2006

  2. p=u,c,t W ± Vpq ? q=d’,s’,b’ CP Violation in SM CKM picture of charged weak currents: (solely responsible for CPV in SM) • But amount of CP violation too small: • - observation: • - area of unitarity triangle: Additional sources of CP violation needed SLUO Anual Meeting 2006

  3. Search for Super-Penguins • Penguin amplitude in SM • Super-penguin, beyond-SM? Example of SUSY diagram SM rules Double-CKM suppression: Loop suppression: Decay rates small BF<7·10-5 • Virtual, heavy particles can appear in loops • - can be relatively large, O(1) • - in general not CP-conserving SLUO Anual Meeting 2006

  4. ~0 CPV Parameter sin2b e+ flavor K+K-K0 tag B0  K+K-K0 amplitudes: e-  • Interference term has different signs for B0/B0bar tags • Interference phase only due to B0/B0bar mixing (in SM) SM CPAsymmetry: (B0/B0bar tags) super penguins same asymmetry for J/YKS and K+K-KS IF: super-penguins exist! or SLUO Anual Meeting 2006

  5. Estimate of Dsin2b in K+K-KS Tree From tree-dominated decays B0->J/yKS (SM reference point): Penguin Experimental average of all penguins (penguin-tree) SLUO Anual Meeting 2006

  6. K+ L’=L B0 KS L K- 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 • CP Violation measurement with additional complication • - CP depends on angular momentum L between K+ and K- • - (K+ K-)KS can be bothCP-even and CP-odd * -sin2b CP(K+K-KS)= +1 L=even +sin2b CP(K+K-KS) = -1 L=odd Dilution if both CP present!! -> (2fodd-1) sin2b How to analyze angular momentum composition? *[ CP(KKKS)= - CP(KKKL) ] SLUO Anual Meeting 2006

  7. CP Content • Fractions of P-wave from analysis of angular moments: • 0.29 ± 0.03 over whole DP • 0.89 ± 0.01 in f(1020) region BABAR-CONF-06/40 (ICHEP06) P-wave strength Fraction of P-wave From 879±36 K+K-KS(p+p-) decays From 624±30 K+K+K- decays Need Dalitz plot analysis to measure CP asymmetry previously: - cut >1.1GeV (assume CP-even) - 1.0045<m<1.0345 (assume CP-odd) SLUO Anual Meeting 2006

  8. B0→K+K-K0Isobar Model toy Dalitz plot fK0 f0(980)K0 X0(1550)K0 Non-resonant Charm(onium) contributions: D-K+, DS-K+ cc0K0 Use flavor-symmetry to relate BABAR’s K+K+K- Dalitz plot SLUO Anual Meeting 2006

  9. Dalitz Plot PDF Measure CP asymmetry in time-dependent Dalitz plot: Five observables: Dt, s(Dt), m(K+K-), cosqH, tag flavor B0 amplitude B0bar amplitude CP Violation: Rate difference Phase difference SLUO Anual Meeting 2006

  10. … Add All K+K-K0 Final States K+K-KS(p+p-) 138 ± 17 K+K-KS(p0p0) f(1020) 879 ± 36 “X0(1550)” Non-resonant cc0 f0(980) K+K-KL 499 ± 52 Add K+K-KS(KSp0p0) and K+K-KL All channels use same Dalitz plot model! ~1500 signal events SLUO Anual Meeting 2006

  11. Average CP-Asymmetry Combine KKKS+-, KKKS00, and KKKL Assume same CPV parameters for all KKK0 KKKS+- alone: SM: ACP=0 b=0.370 SLUO Anual Meeting 2006

  12. Measurement ofb • Assume final state is mixture of CP-eigenstates (partial waves) both real and imaginary b/c of CP-even, -odd interferences (->2b) real in Q2B analyses (->sin2b) p/2-beff p/2-beff beff 4.6s SLUO Anual Meeting 2006

  13. CPV in Low K+K- Mass • Resonant fractions for m(K+K-)<1.1GeV • Low-K+K- mass fit for CPV parameters in fK0 and f0K0 to reduce dependence on Dalitz plot model • fK0 theoretically very clean s(sin2b)~ O(1%) • Fix S-wave, float isobar parameters for P-wave SLUO Anual Meeting 2006

  14. CPV in Low K+K- Mass Combined KKKS+-, KKKS00, and KKKL asymmetry plot ±15MeV under f fKS SM: ACP=0 b=0.370 f0KS • CPV measurements in f0Ks and fKs correlated (one background for the other) • cross-check with Q2B analysis • syst. errors dominated by Dalitz plot model • consistent with SM, Belle SLUO Anual Meeting 2006

  15. 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 • Lower sin2b 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 SLUO Anual Meeting 2006

  16. More Slides SLUO Anual Meeting 2006

  17. K+ S-wave KS K- P-wave Angular Moments - Model-independent approach to extract CP content [BABAR, PRD71,091102] - Assume S and P-waves decaying into K+K- K+K- CMS - Decay rate in terms of moments of Legendre polynomials: - Moments <PL> computed using sPlots [Pivk, Le Diberder, Nucl.Inst.Meth. A555] - Fraction of P-wave: (angular momentum conservation) SLUO Anual Meeting 2006

  18. Belle’s helicity plot (±10MeV under f mass) [Hazumi ICHEP06 talk] BABAR/Belle 2006: B0KKKS BABAR Belle B+K+K+K- (230MBB) PRD72,032003(2006) non-zero yield below and above f peak! B0K+K-K0 (347MBB) (bkg substracted) hep-ex/0607112 • Belle’s estimate (±10MeV): • K+K+K- Dalitz (140 fb-1) ~2.75±0.14% • ignores f0(980) • 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 SLUO Anual Meeting 2006

  19. i j k Dalitz Plot Isobar Model “Non-resonant” “resonant” i k Decay amplitude ∑res {ij}res  = B j B Resonant amplitude: Blatt-Weisskopf form factors Breit-Wigner Angular correlations Coupled channel BW (Flatté) Single channel BW SLUO Anual Meeting 2006

More Related