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CP Violation and B-mixing in CDF-II

CP Violation and B-mixing in CDF-II. IV International Conference on Hyperons, Charm and Beauty Hadrons June, 27-30, 2000 Valencia,Spain. Alberto Ruiz Jimeno Instituto de Física de Cantabria (CSIC-Univ. Cantabria) Santander,Spain. CP-Violation and B-mixing in CDF-II. Outline.

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CP Violation and B-mixing in CDF-II

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  1. CP Violation and B-mixing in CDF-II IV International Conference on Hyperons, Charm and Beauty Hadrons June, 27-30, 2000 Valencia,Spain Alberto Ruiz Jimeno Instituto de Física de Cantabria (CSIC-Univ. Cantabria) Santander,Spain BEACH2000

  2. CP-Violation and B-mixing in CDF-II Outline • Short summary of results on CP Violation and B-Mixing from Run-I • Detector Upgrade • Flavor tagging • Prospective for CP Violation and B-mixing in Run-II • Conclusions BEACH2000

  3. CP-Violation and B-mixing in CDF-II 1992-1995 : 110 pb -1 collected Bd mixing Bs mixing BEACH2000

  4. CP-Violation and B-mixing in CDF-II Golden mode for CP-violation analysis: B0 J/y Ks (measure of sin 2b) Total signal: 395 31 events +0.41 Sin 2 b = 0.79 -0.44 BEACH2000

  5. CP-Violation and B-mixing in CDF-II Fermilab Main Injector: • 150 GeV accelerator 1/2 Radius of Tevatron: • 20 times luminosity ( starting 8-20 x 1031 cm-2 seg-1) •  2 fb -1 in two years • 15 fb -1 up to 2006 • Proton/antiproton bunch spacing: • 132 nsec ( 108 bunches) • 396 nsec (36 bunches) • Overlapping interactions ( 2-6 on average) BEACH2000

  6. CP-Violation and B-mixing in CDF-II Tracking: SVX-II( 5 layers, double side. 2.4-10.7 cm. 60 m pitch. 12 m resolution. |h|< 2 ) ISL( 2 layers, double side. 20 -28 cm. 110 -146 m pitch. 16 m resolution. |h|< 2 ) COT(Open cell drift chamber. Drift time < 132 nsec. 44-132 cm. 96 layers, 8 superlayers, 4 r-f, 4 z. 180 m resolution. |h|< 1 dE/dx information ) Muon systems, double coverage. |h|< 2 New scintillating tile plug calorimeter 1<|h|< 3 BEACH2000

  7. CP-Violation and B-mixing in CDF-II Beyond Baseline: Layer 00 ( rad-hard single-sided silicon layer. 1.6 cm. 50 m pitch) T.O.F.216 bars Bicron BC408. 4x4 cm. 2.8 m.long Hamamatsu PMT´s 19 stages fine-mesh 100 psec. Resolution (see S.Cabrera talk) BEACH2000

  8. CP-Violation and B-mixing in CDF-II 2s K/p separation for p<1.6 GeV/c TOF and dE/dx complementary BEACH2000

  9. CP-Violation and B-mixing in CDF-II Trigger: Level 1: 50 Khz. Muons (CMU stubs, pt>3 GeV/c) Electrons ( 4 GeV single tower) XFT: extremely fast tracks: | pt | > 1.5 GeV/c | z | < 155 cm. Between inner and outer COT radius Performance: s(pt )/ pt2 = 0.012 (GeV/c) DF6 ( R = 106 cm )< 0.0015 rad XTRP: tracks distribution BEACH2000

  10. CP-Violation and B-mixing in CDF-II • Trigger: • Level 2: 300 Hz. (many asynchronous subsystems) • (e.g.): • Two-tracks ( e.g. B pp) • All hadronic B- trigger • Soft lepton + XFT track • (using SVT) SVT trigger:information from XFT and silicon vertex detector Level 3: 30 Hz. ( Farm of computers) BEACH2000

  11. CP-Violation and B-mixing in CDF-II Lepton + displaced track trigger 120 m < |d0 |< 1 mm. BEACH2000

  12. CP-Violation and B-mixing in CDF-II Signal sizes for some channels, before tagging , for 2 fb-1: ( S/B studied for each channel, using Run I data, when possible) BEACH2000

  13. CP-Violation and B-mixing in CDF-II Flavor tagging methods: To determine the flavor at production time Opposite side Tags (OST): Soft lepton tag (SLT) Opposite side Kaon tag Jet charge (JTEQ) Same side tag (SST) -> K-p+ Kaon tags need TOF BEACH2000

  14. CP-Violation and B-mixing in CDF-II TOF enhances D K veto SST Pythia MC reproduces SST in data OST Kaon BEACH2000

  15. CP-Violation and B-mixing in CDF-II Tagging Efficiency x (Dilution Factor)2 (eD2) BEACH2000

  16. CP-Violation and B-mixing in CDF-II Unitarity triangle a = arg ( -VtdVubV*tbV*ud ) b = arg ( -VcdVtbV*cbV*td ) g = arg ( -VudVcbV*ubV*cd ) ( r , h) a g b ... 0 1 Wolfenstein parametrization BEACH2000

  17. CP-Violation and B-mixing in CDF-II b t q MIXING W W BEACH2000

  18. CP-Violation and B-mixing in CDF-II • Without L00, 60 fs • With L00, 45 fs Bs oscillations True versus meas. Asym. S/B = 1/2 Potential of Bs mixing observation BEACH2000

  19. CP-Violation and B-mixing in CDF-II Bs mixing in semileptonic decays Bs Ds l n, Ds* l n Dsfp,K*K Trigger: lepton + SVT track (pt >2 GeV/c, d0>120 m) st corrected by K factor • reach of Hadronic Bs decays • including 3d vertex correction • without 3d vertex correction Xs reach: BEACH2000

  20. CP-Violation and B-mixing in CDF-II CP violation: Channel J/Y K s ACP(t) requires flavor tagging at production, signal reconstruction and decay time Scaling RunI analysis (including TOF) 10 K events, s(sin(2b)) = 0.067 New triggers, 30Kevents, s(sin(2b)) = 0.043 BEACH2000

  21. CP-Violation and B-mixing in CDF-II If only one weak phase, fA: If more than one weak phase ( case of penguin pollution, as in Bd pp), fA1 ,fA2: BEACH2000

  22. CP-Violation and B-mixing in CDF-II Measuring g from: (Penguin/tree) g better than 10º with 2 fb-1 BEACH2000

  23. CP-Violation and B-mixing in CDF-II Measuring g from: A toy MC 2, 5, 10, 20 fb-1 BEACH2000

  24. CP-Violation and B-mixing in CDF-II Measuring g with: (If x is a strong phase) Use as f, the double Cabibbo suppresed decays K-p+ as well as f* = K- p+ p -p+ Unknowns x x* g b in the four equations from d and d* BEACH2000

  25. CP-Violation and B-mixing in CDF-II Defining the asymmetry Expected signal rate in 2 fb-1, is in the order of 100 events after trigger selection. Background estimation is on study g x BEACH2000

  26. CP-Violation and B-mixing in CDF-II Measuring from: K+ m+ p.d.f. ( CP even decays): 3/8 ( 1 + cos2 qT) p.d.f. ( CP odd decays): 3/4( sin2 qT) f qT m- K- Heavy and light weak eigenstates are in a close approximation the CP even and odd states. The qTdistribution of the decay products allows for a separation of the CP eigenstates Toy MC results In Run II more than 4000 events expected. will be measured with a value of 0.15 and a precision of about 0.051, if the CP even fraction is 0.771. Using other channels ( Bs D+sDs -) precision will be better BEACH2000

  27. CP-Violation and B-mixing in CDF-II CONCLUSIONS CDF will start data taking in March 2001 The prospects for B-physics are very good, from the start BEACH2000

  28. CP-Violation and B-mixing in CDF-II More information: S.Bailey, P.Maksimovic: CDF/ANAL/BOTTOM/CDFR/4863 A.Cerri,G.Punzi,G.Signorelli: CDF/ANAL/BOTTOM/PUBLIC/4881 M.Paulini: CDF/PUB/BOTTOM/PUBLIC/5200 A. Cerri: CDF/DOC/BOTTOM/CDFR/5243 F.Würthwein: CDF/ANAL/BOTTOM/CDFR/5271 C.Blocker: CDF/BOTTOM/PHYS/PUBLIC/5289 M.Tanaka: CDF/ANAL/BOTTOM/CDFR/5290 W.Wester: CDF/ANAL/BOTTOM/CDFR/5298 F.Azfar, L.Lyons, M.Martin, C.Pauss, J.Tseng: CDF/ANAL/BOTTOM/CDFR/5300 M.Kirk, J.Lewis, M.Tanaka: CDF/DOC/TRIGGER/CDFR/5324 B.Wicklund: Contribution to the RUN II B-Workshop, Fermilab M.Jones: Contribution to the RUN II B-Workshop, Fermilab J.Kroll: Contribution to the RUN II B-Workshop, Fermilab ……..Many thanks to all of them BEACH2000

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