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B d,s ->h 1 h 2 : BR, CP asymmetries, and lifetimes

B d,s ->h 1 h 2 : BR, CP asymmetries, and lifetimes. . . S. Budroni, S. Donati, M. Donega’ , S. Giagu, M. Morello, G. Punzi, D. Tonelli CDF Collaboration Meeting February 3, 2006. Notes: 6175, 6356, 6357, 6453, 7066, 7978, 8057

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B d,s ->h 1 h 2 : BR, CP asymmetries, and lifetimes

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  1. Bd,s->h1h2: BR, CP asymmetries,and lifetimes   S. Budroni, S. Donati, M. Donega’, S. Giagu, M. Morello, G. Punzi, D. Tonelli CDF Collaboration Meeting February 3, 2006 Notes: 6175, 6356, 6357, 6453, 7066, 7978, 8057 (+linked notes on dE/dx calibrations and isolation studies) Mauro Donega’ - CDF collaboration meeting February 3, 2006

  2. Physics motivations   • Bd,s->h1h2= Bd->k, Bd-> ,Bs->KK , Bs->K • Accessible to B factories: Bd->k, Bd->  • Only at TeVatron (until >2007): Bs->KK , Bs-> K • Possible measurements: • Today: • direct CP asymmetry in Bd->k, Bs-> K • (counting experiment) • Future: • CP asymmetry in mixing Bd-> ,Bs->KK • (requires time dependent analysis) • Short term goal: UsingBd->k,Bd-> BR, constrain the relevant hadronic penguin parameters. • Long term goal: combine time-dependent Bd->  and Bs->KK • asymmetries (+other external input) to measure g Tree Penguin PHYSICAL REVIEW D 66, 054009 2002 Physics Letters B 4591999.306–320 Mauro Donega’ - CDF collaboration meeting February 3, 2006

  3. Physics motivation (cont’d) • Bs described as a two states system. • Evolution through Schroedinger equation: • off diagonal terms ->mixing • M12, G12, f = arg(- M12/G12) • What we measure: • Dm = MH –ML ~ 2|M12| DG = GL–GH~ 2| G12 |cos(f) • SM: f ~0 -> CP eigenstates ~ mass eigenstates • Bs-> is predicted to be 95% CP even => ct(Bs->KK) ~1/ GL • Bs->KK lifetime combined with FS (t) can give DG. • Measurement of Bs->KK lifetime can be strongly affected by • new CP violating physics => sensitivity to New Physics _ Mauro Donega’ - CDF collaboration meeting February 3, 2006

  4. Two groups: BR, ACP andLifetimes worked on the same data sample: Ideal x-check of the common results ! Signal extraction DATA Optimized sample Fitter Kinematics+PID+Lifetimes Fitter Kinematics+PID Raw fractions Acceptance corrections BR and ACP Lifetimes Mauro Donega’ - CDF collaboration meeting February 3, 2006

  5. Data and MC samples Dataset: xbpp0d ~355 pb^-1 (BPAK good run list applied) Triggers: B_PIPI B_PIPI_HIGH_PT (~7% of the total) MonteCarlo: BMC framework 5.3.4 Simulated the four signal modes: Bd->Kp, Bd->pp, Bs->KK, Bs->Kp Reconstruction: CharmMods – 5.3.4 Track refit with L00 Primary vtx from beamline Mauro Donega’ - CDF collaboration meeting February 3, 2006

  6. Signal extraction Optimization performed independently by the two groups Lead to similar set of cuts: S/B~ 2 Mauro Donega’ - CDF collaboration meeting February 3, 2006

  7. Background mass description B->hh signals to be disentangled Bd/s/K Include Bd/s/K in the mass description (little bias to the lifetimes, included as systematic uncertainty) combinatorial Lifetimes • Fit combinatorial bkg • Shape • fraction BR ACP Mauro Donega’ - CDF collaboration meeting February 3, 2006

  8. Disentangling the signal fractions Bdp+p- e mass    BdK-p+ Bd K+p- K mass mass   p BsK+K- mass 2 Momentum (GeV/c) BPAK calibrations  Mauro Donega’ - CDF collaboration meeting February 3, 2006

  9. Extract the lifetimes MC based lifetime extraction (tested on B->Dp decays CDF7386) Events after trigger+offline cuts = Lifetime MC ev/ev ct error Background described with a template On the right sideband (combinatorial only) = Mauro Donega’ - CDF collaboration meeting February 3, 2006

  10. Raw fractions results Lifetimes BR, ACP Compatible results ! Mauro Donega’ - CDF collaboration meeting February 3, 2006

  11. BR ACP =XXX ± 0.039 (stat) ± 0.013(syst) Mauro Donega’ - CDF collaboration meeting February 3, 2006

  12. mass z1 ct (cm) a p1+p2 z2 Lifetimes results In agreement with world average 460 ± 4 um ct(Bd)floating ct(Bd)PDG constrained Mauro Donega’ - CDF collaboration meeting February 3, 2006

  13. Lifetimes BR ACP 5.6 um 0.013 Systematic uncertainties Mauro Donega’ - CDF collaboration meeting February 3, 2006

  14. Status (360 pb-1) and Plans (1 fb-1) • Status: • BR and ACP pre-blessed on January 26th, 2006 • Lifetime measurement blessed on January 26th, 2006 • Plans: • Bless BR and ACP 360 pb-1and move to 1 fb-1 • Lifetimes move to 1 fb-1: • Data skimming + MC production (in progress) • dE/dx calibrations (~done) Mauro Donega’ - CDF collaboration meeting February 3, 2006

  15. Summary The charmless two body B decay sample is Extremely Rich ! And leads to world class B physics measurements. We are upgrading the BR and ACP measurements and for the first time we measured the lifetimes on 360 pb-1: ct (Bd) = 452 ± 24 ± 6 um ct (BsK+K-) = 458 ± 53 ± 6 um DG(CP) / G (CP) = -0.08 ± 0.23 ± 0.03 Mauro Donega’ - CDF collaboration meeting February 3, 2006

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