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Recent CP violation results from BaBar

Recent CP violation results from BaBar. F. Mart í nez-Vidal IFIC – Universitat de Val è ncia-CSIC Representing the BaBar Collaboration at . Supersymmetry 2011 (SUSY 2011) FNAL, Batavia , Illinois (USA) 28 th August to 2 nd September 2011. CP violation. CKM unitarity triangle.

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Recent CP violation results from BaBar

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  1. Recent CP violation results from BaBar F. Martínez-Vidal • IFIC – Universitat de València-CSIC • Representing the BaBar Collaboration at Supersymmetry 2011 (SUSY 2011) FNAL, Batavia, Illinois (USA) 28th August to 2nd September 2011

  2. CP violation CKM unitarity triangle • Leading source of quark-sector CP violation established (mostly by BaBar and Belle) • CKM mechanism • Overall good consistency between measurements and predictions within CKM • ~2.8s tension for sin2bB(cc)K and BF(B+t+n) • New physics (NP) can be revealed in low-energy flavor processes…especially in loops • Particularly fruitful are processes with (very) small effects predicted by the SM • NP in generalinduces (additional) FCNC and CP-violating phases PRD 84, 033005 (2011) • Yet, need more and precise CP asymmetries sensitive to NP(loop level) • …and more precise SM candle (tree level)measurements (CKM angle g, or |Vub|) • The particle can be very heavy…can probe NP at the multi-TeV scale, but need huge data sets…Luminosity frontier • Complementary to direct searches at energy frontier 1 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  3. Outline • The BaBar detector & data set • CP violation in D decays • D+ p+K0s • D+(s)K+K0sp+p- and D0K+K-p+p- • CP violation in t decays • t-p-K0snt • CP violation in Charmless B decays • B+ (r0/f0)K*+ and B0 r-K*+ • B0 K+p-p0 and B+ K+p0p0 • Conclusions • BffK New CP violation results related to the measurement of the CKM angle g have been presented also in the last year, but will not be discussed in this talk 2 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  4. BaBar detector 1.5T solenoid EMC 6580 CsI(Tl) crystals DIRC (PID) 144 quartz bars 11000 PMs e+ (3.1 GeV) Drift Chamber 40 stereo layers e- (8-9 GeV) Silicon Vertex Tracker 5 layers, double sided strips Instrumented Flux Return iron / RPCs / LSTs (muon / neutral hadrons) • Asymmetric B-factory: Ecms = 10.58 GeV • Performed a wide range of flavor physics results in B, Cham and t sectors • General purpose detector in e+e- environment: precision tracking, photon/electron detection, particle ID, muon/KL identification. Very stable over the 9 years of operation 3 3 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  5. B factories Data set • 530 fb-1 recorded in the 9 years of operation 14.5 fb-1 30.2 fb-1 430 fb-1 54 fb-1 Off-(nS) 4 fb-1 above (4S) ≈ 470106 BB (0.5Belle) ≈ 690106 cc ≈ 500106 ≈ 1.2108 (3S) (7Belle+Cleo) ≈ 1.0108 (2S) (0.5Belle+Cleo) 4 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  6. Recent CP violation results: • D decays 5 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  7. D decays: motivation csud(CF) and cdus(DCS) cudd(SCS) and cuss(SCS) c u W+ • Direct CP violation in D decays arises through interference between: • In the SM is CKM suppressed O(10-3) or less • NP can increase or reduce the effect • e.g. additional CP phase from charged Higgs boson • SCS decays are more likely to show the effect if present • Current experimental sensitivity O(10-3) c s , d Vcs s Vcs W+ u g d , s d, s d, s Penguin Tree PRD 75, 036008 (2007) hep-ph/0104008 (2001) PRD 51, 003478 (1995) 6 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  8. D+p+K0s: experimental technique • Due to CPV in mixing in the kaon sector, the direct CP asymmetry is expected to be • Signal yields from likelihood fit to m(p+K0s), with selection based on a Boosted Decision Tree with 7 variables: • 807K D±signal events • Measure J. Phys. G 37, 075021 (2010) hep-ph/0104008 (2001) Forward-Backward asymmetry Detector charge asymmetry • Data-driven method to correct for Ae • Use tracks from e+e-(4S)BB decays (isotropic in rest frame) to map the ratio of p+/p- detection efficiencies • Offset on ACP+0.05% 7 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  9. D+p+K0s: results 470 fb-1 • Use data-driven method to extract AFB, and ACP in bins of polar angle Consistent with SM prediction (-0.332±0.006)% PRD 83, 071103(R) (2011) 8 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  10. D+(s)K+K0sp+p- : experimental technique • Measure a T-odd observable • If we assume CPT invariance  CP violation • Define T-odd triple products for D+(s) and D-(s) • Define the T-odd asymmetries • FSI could introduce fake T-odd asymmetries. To remove, define • Signal selection optimized by means of likelihood ratio with 3 variables • Yields obtained from simultaneous likelihood fit to m(K+Ksp+p-) distributions for D+, D-, Ds+, Ds-, for >0 and < 0 triple products (8 samples in total) T-violating asymmetry PRD 66, 094004 (2002) PRD 64, 116003 (2001) PLB 538, 309 (2002) Int.J.M.Phys. A24, 657 (2009) 9 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  11. D+(s)K+K0sp+p-: results 520 fb-1 • ~21K D± and 30K Ds± signal events • Results • Similar BaBar analysis using D0K+K-p+p- • ~47K D0/D0 signal events FSI seem to be larger in D+s than D+ decays 1107.1232 [hep-ph] (2011) T-violating asymmetry consistent with 0 10 improvement wrt previous result 1105.4410 [hep-ex] (2011). Accepted by PRD(RC) PRD 81, 111103(R) (2010) 10 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  12. Recent CP violation results: • t decays 11 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  13. t-p-K0snt: motivation t- nt W- • SM model predicts the decay amplitude and its CP conjugate to be the same  no direct CP V is expected • However, like in D+p-Ks, due to CPV in the kaon sector, the CP asymmetry is expected to be • A deviation of the measured AQfrom AQSM would be a hint of NP • e.g. an additional CP violating phase from an exotic charged Higgs boson • Can consider • p0s are expected not to change the asymmetry u p- d Tree s d K0 PLB 625, 47 (2005) Note: the sign of the asymmetry is opposite to that of D+p+K0s PLB 398, 407 (1997) 12 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  14. t-p-K0snt:experimental technique Selected event topology e+orm+ • Reconstruct up to 3p0s • Electron andmuon tags • pl* > 4 GeV to reduce background from non-t-pairs • Reconstructed hadronic mass < 1.8 GeV • Rejects qq background Invariant mass of the hadronic final state (0p0s) • Remaining qq and K0s background further reduced using likelihood ratio technique • Visible energy, number of neutral clusters, thrust, total transverse momentum • Displaced vertex, invariant mass, momentum and polar angle of the K0s candidate Preliminary 13 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  15. t-p-K0snt:results 437x106t+t- pairs • Measured raw ACP value (after subtraction of qq background and non-K0st decays) has to be corrected by • Different nuclear reaction cross-section of K0 and K0 with material detector • (0.14±0.03)% for e-tag, (0.14±0.02)% for m-tag • Errors include uncertainties from kaon-nucleon cross-sections and isospin • Dilution from background modes including K0s • Result Systematic uncertainties 3s from the SM prediction Preliminary. To be submitted to PRD(RC) 14 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  16. Recent CP violation results: • Charmless B decays 15 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  17. Charmless B decays • Many such decays are dominated by bs penguins • Tree amplitudes subdominant in SM • Time-dependence and FSI (intermediate states) allow to measure the CKM angles • NP can change CP asymmetries, branching fractions and polarizations in BVV decays • Use kinematic constraints from beam energies • Event shape variables combined into a linear (Fisher) or non linear (NN) combination. Tagging (other “B”) information often used Tree Penguin • Apply selection to reject continuum • As variable in ML fit 16 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  18. B+r0K*+ and B+f0K*+ 467x106 BB pairs • B+r0K*+ is a VV decay. QCDF • Predicts longitudinal polarization fL~0.9 • Works for Brr, not for other VV decays where fL~0.5 (“polarization puzzle”) • Reconstruct r0/f0p+p- , K*+ Ksp+,K+p0 • ML fit with 7 variables: mES, DE, NN, invariant masses, cosq • Measure simultaneously BFs, ACPs, fLs • First observation of B+r0K*+ with 5.3s • Consistent with QCDF, BF  (5±1)10-6 • fL compatible with other bs decays NPB 774, 64 (2007) PRD 79, 039903 (2009) ρ0K*+ signal f0K*+ signal PRD 83, 051101 (2011) 17 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  19. B0r0/f0K*0 and B0r-K*+ Preliminary 471x106 BB pairs • Very similar to previous analysis • f2(1270)K*0 events extrapolated from mpp sideband • First 5s observations of B0r-K*+ and B0f0K*0 • BF consistent with QCDF, BF  510-6 • fLinconsistent with QCDF, but consistent with experimental results from other bs decays • Experiment: • QCDF: • Also measure scalar (Kp)*0 and tensor K*2(1430) states in a (Kp) “high-mass” region (not shown here) 18 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  20. B0K+p-p0 and B+K+p0p0 • We expect ACP(B0K+p-)  ACP(B+K+p0) • Experimentally • ACP(B+K+p0) = +0.050 ± 0.025 • ACP(B0K+p-) = -0.098 ± 0.012 • Is there a similar K*p puzzle? • Have to measure B0K*+p- and B+K*+p0 • P/T predicted to be 2-3 larger than in Kp • Many resonances interfere  full amplitude (Dalitz plot) analysis • Large backgrounds • qq + many different BB categories + large amount of signal misreconstructed (especially for K+p0p0), all accounted for 5s difference SM or NP? “Kp puzzle” Mod.Phys.Lett.A 24, 1983 (2009) 19 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  21. B0K+p-p0 and B+K+p0p0: results PRD 83, 112010 (2011) 454x106 BB pairs • Perform ML fit with mES and NN, and for K+p-p0 only, also DE and DP • For B0K+p-p0 • BF(B0K+p-p0) = (38.5 ± 1.0 ± 3.9)10-6 • ACP(K*+p-) = -0.29 ± 0.11 ± 0.02 • When combined with B0Ksp+p- : • For B+K+p0p0 • First inclusive measurement • Measure resonances in a two-body fashion • More statistics is needed to better test ACP(K*+p-) ACP(K*+p0) 3.1s evidence for direct CPV • ACP(K*+p-) = -0.24 ± 0.07 ± 0.02 471x106 BB pairs 10s significance • To be compared to • -0.24 ± 0.07 ± 0.02 Preliminary 20 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  22. Conclusions • ended data-taking in 2008 but continues to produce many new physics results on CP violation in D, t and B decays • Only the most recent new results shown in this talk • Most results agree with SM predictions but some puzzles remain • Charmless BVV “polarization” puzzle • “Kp” puzzle • …and a 3s effect has just appeared • Direct CP violation int-p-K0snt • A larger data sample is required to perform stringent tests and searches • We look forward for many interesting flavor results from present and future flavor facilities 21 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  23. Bonus slides 22 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

  24. BffK • Interference at mff ~mhc • SM tree and penguin have  the same weak phase • NP in the penguin could induce large direct CPV BffK (Penguin) Bhc(ff)K (Tree) PLB 583, 285 (2004) • ML fit in mES, DE, Fisher (and 2 f masses for BF) • Use (mf1,mf2) sidebands to extractpeaking backgrounds from BfKKK, 5K, f0fK, f0KKK decays mff<2.85 GeV region 464x106 BB pairs First 5s observation of B0ffK0 ACP consistent with 0 (SM expectation) PRD 84, 012001 (2011) 23 SUSY 2011, FNAL Recent CP violation results from BaBar F. Martínez-Vidal, IFIC-Valencia

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