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はじめに ＣＤＦ実験の成果 ＣＤＦ実験の現状 ＣＤＦ実験の今後の計画

CDF 実験の現状と将来. 金　信弘 筑波大学物理学系 For the CDF Collaboration. 物理学セミナー（大阪市立大学） 2002 年 11 月 21 日. はじめに ＣＤＦ実験の成果 ＣＤＦ実験の現状 ＣＤＦ実験の今後の計画. 素粒子と素粒子間の力（素粒子物理標準理論）. 物質を構成する粒子（フェルミオン）. クォーク. 　電荷 2/3 - 1/3 - 1 0. アップ (0.002) 　　　チャーム (1.3) 　　　トップ (175 )

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はじめに ＣＤＦ実験の成果 ＣＤＦ実験の現状 ＣＤＦ実験の今後の計画

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  1. CDF実験の現状と将来 金　信弘 筑波大学物理学系 For the CDF Collaboration 物理学セミナー（大阪市立大学） 2002年11月21日 • はじめに • ＣＤＦ実験の成果 • ＣＤＦ実験の現状 • ＣＤＦ実験の今後の計画

  2. 素粒子と素粒子間の力（素粒子物理標準理論）素粒子と素粒子間の力（素粒子物理標準理論） 物質を構成する粒子（フェルミオン） クォーク 　電荷 2/3 - 1/3 - 1 0 アップ(0.002)　　　チャーム(1.3)　　　トップ(175 ) ダウン(0.005)　　　ストレンジ(0.14)　 ボトム( 4.2) レプトン 電子(0.0005)　　 ミュー粒子(0.106)　　タウレプトン(1.8) 電子ニュートリノミューニュートリノタウニュートリノ 力を伝える粒子（ゲージボソン） 弱い力 電磁気力 強い力 （　）内の数字はGeVの 単位で書かれた質量 グルオン(0)　　光子(0)　　　Ｗ粒子(80) 　　　　　　　　　　　　　 Ｚ粒子(91)

  3. 質量の起源（ヒッグス機構） 　ヒッグスポテンシャル V (f) = m2f2 /2+ lf4 /4 ( l m2 > 0 (ビッグバン直後) 　　　　　　真空の相転移（対称性の破れ） 　m2 < 0 (現在)

  4. 大統一理論三つの力（電磁力、弱い力、強い力）は、宇宙創生直後の高温時には対称性が成り立ち、同一の力であった。それが冷えてきたときに対称性が破れて異なる力に見えるようになった。大統一理論三つの力（電磁力、弱い力、強い力）は、宇宙創生直後の高温時には対称性が成り立ち、同一の力であった。それが冷えてきたときに対称性が破れて異なる力に見えるようになった。 超対称性理論すべてのフェルミオン（ボソン）には超対称粒子のボソン（フェルミオン）のパートナーが存在する。この超対称性を仮定すると、三つの力の大統一がある高温状態で成り立つ。　この理論は有望であると考えられている。この理論が正しければ、質量150GeV/c2以下のヒッグス粒子が存在するし、また標準理論で期待される以上のＫ中間子、τ粒子、Ｂ中間子の稀崩壊が起こる。

  5. ビッグバン宇宙と素粒子物理 CDF 　　　　　大統一理論 　真空の相転移 　粒子反粒子対称性の破れ 電弱統一理論 　ヒッグス粒子

  6. CDF実験の主要な成果 陽子反陽子衝突実験（米国フェルミ国立加速器研究所） 1987年　　実験開始 1994年トップクォーク発見 1998年Bc中間子発見 2001年3月　実験再開 ヒッグス粒子探索 Ｂ中間子のＣＰ非保存 　トップクォークの物理

  7. MW vs. MTOP Higgs Mass Constraint From Mtop(CDF,D0), MW(CDF,D0,LEPII) and other electroweak results, MHiggs < 215 GeV/c2 at 95% C.L. Ref. LEP ElectroweakWorking Group, CERN EP/2000-016

  8. ヒッグス粒子（標準模型）の生成断面積と崩壊分岐比ヒッグス粒子（標準模型）の生成断面積と崩壊分岐比 生成断面積 生成断面積ｘ分岐比

  9. CDF Run I VH searches ( 106 pb-1) Expect: 600 events Observe: 580 events Expect: 305 st 6.00.6 dt Observe: 36 st 6 dt Expect: 3.20.7 st Observe: 5 Expect: 39.24.4 st 3.90.6 dt Observe: 40 st 4 dt

  10. VH Production Cross Section Limit 95% CL Limit is about 30 times higher than SM prediction for Mhiggs = 115GeV/c2.

  11. 2001年4月～2004年 Run2a ( 2fb-1 ) 2005年～2008年 Run2b ( >13fb-1 ) 2TeV陽子反陽子衝突実験（米国フェルミ国立加速器研究所）

  12. The CDF Collaboration North America Europe Asia 3 Natl. Labs 28 Universities 1 Universities 1 Research Lab 6 Universities 1 University 4 Universities 2 Research Labs 1 University 1 University 5 Universities 1 Research Lab 1 University 3 Universities Totals • 112 countries • 58 institutions • 581 physicists

  13. Tevatron History and Future Discovery of top, Bc, … MW, Mtop, sin2b, … measurements 5 x 1032 cm-2 s-1 2 x 1032 cm-2 s-1 Tevatron Collider Luminosity 2 fb-1 15 fb-1 0.1 fb-1 2000 2002 2004 2006 2008 Run : 0 Ia Ib IIa IIb s : 1.8 TeV 1.96 TeV

  14. Tevatron status Initial Luminosity • Tevatron operations started in March 2001 • Luminosity goals for run 2a: • 5-8x1031 cm-2sec-1 w/o Recycler • 2x1032 cm-2sec-1 with Recycler • Achieved: • 3.8x1031 cm-2sec-1 in October ’02 • Now recovered from June shutdown to improve p-bar cooling • 120 pb-1 delivered until October ’02 • 90 pb-1 are on tape • 10 – 20 pb-1used for analyses shown here (details) July 01 Now 120 pb-1 Integr. Luminosity Delivered 90 pb-1 plans On tape

  15. CDFII Detector

  16. Muon System Central Calor. New Solenoid Old Partially New Muon Plug Calor. Time-of-Flight Drift Chamber Silicon Microstrip Tracker Front End Electronics Triggers / DAQ (pipeline) Online & Offline Software

  17. Detector Performance：SVX • Silicon detectors: • Typical S/N ~12 • Alignment in R-f good • R-z ongoing Details

  18. Full silicon acceptance is in sight …The last 10% of the job takes the second 90% of the effort (but not time!) • Commissioning: • L00 > 95% • SVXII > 90% • ISL > 80% • ISL completing cooling work % of silicon ladders powered and read-out by silicon system vs. time Back Back to index

  19. Detector Performance：TOF • TOF resolution within 10 –20% of 100ps design value • Improving calibrations and corrections S/N = 1942/4517 TOF S/N = 2354/93113

  20. Detector Performance：XFT • XFT: L1 trigger on tracks • full design resolution • DpT/p2T = 1.8% (GeV-1) • Df = 8 mrad Efficiency curve: XFT cut at PT = 1.5 GeV/c Offline track XFT track

  21. Detector Performance：SVT 8 VME crates Find tracks in Si in 20 ms with offline accuracy Online track impact param. s=48 mm 90% • Secondary VerTex L2 trigger • Online fit of primary Vtx • Beam tilt aligned • D resolution as planned • 48 mm (33 mm beam spot transverse size) Efficiency soon 80%

  22. Physics with CDF-II • Use data to understand the new detector: • energy scales in calorimeter and tracking systems • detector calibrations and resolutions • tune Monte Carlo to data • Use data to do physics analyses • Quality of standard signatures • Rates of basic physics signals • Surprisingly some results are already of relevance in spite of the limited statistics • summary of a lot of work list

  23. EM Calorimeter scale NZ = 247 FB asymmetry Central-central • 638 Z  e+e- in 10 pb-1 • s(M) ~ 4 GeV • Check Z mass in data and simulation after corrections • Central region: • Mean: +1.2% data, -0.6% sim. • Resolution: +2% simulation • Forward region (Plug): • Mean: +10/6.6% data, +2.0% simulation • Resolution: +4% simulation Central-West plug Central-East plug NZ (W+E) = 391

  24. Reconstruct Z  ee; measure AFB Uses silicon to tag e± charge Both e ||>1 NZ(PP) = 160 Both e ||<1 NZ(CC) = 247 s(M) ~ 4 GeV Central-Plug Dielectron Mass One ||<1, one ||>1 NZ(CP) = 391 AFB will be an additional handle in Z’ searches

  25. Measurements with high Et e± Selection details • Good modeling of observed W en distributions MET resolution from MB data consistent with Run 1 MET detail

  26. Measure s•B(Wen) 0.16 soon! W cross section: sW*BR(Wen) (nb) = 2.60±0.07stat±0.11syst ±0.26lum Background (8%): - QCD: 260 ± 34 ± 78 - Z ee: 54 ± 2 ± 3 - Wtn: 95 ± 6 ± 1 5547 candidates in 10 pb-1

  27. High-Pt muons: Z m+m- • Clear Z m+m- signal • require COT•CMU•CMP • CDF’s purest muons: ~8l m1 CMU m2 CMP 57 candidates 66<M<116 GeV NZ = 53.2±7.5 ±2.7

  28. Measurement of sB(Wmn), R 4561 candidates in 16 pb-1 (require COT•CMU•CMP) 12.5% background: - Z mm: 247 ± 13 - Wtn: 145 ± 10 - QCD: 104 ± 53 - Cosmics: 73 ± 30 s•B(Wmn) = 2.70±.04stat±.19syst ±.27lum Many uncertainties, e.g. lumi, cancel in ratio: R = s•B(Wmn) / s•B(Zmm)= 13.66±1.94stat±1.12syst(1.5s from SM)  G(W)= 1.67±0.24stat±0.14syst MT Measure a precisely predicted ratio  establish tight feedback loop on muon detection, reconstruction, and simulation

  29. W  t n • Evidence for typical t decay multiplicity in W t n selections • t channel important for new physics searches

  30. Measurements with jets • Raw Et only: • Jet 1: ET = 403 GeV • Jet 2: ET = 322 GeV Jet expectations Raw jet distributions

  31. central calor. Plug region Plug region Hadronic Energy Scale • Use J/y muons to measure MIP in hadron calorimeters • (Run II)/(Run 1) = 0.96±0.05 q g g q • Gamma-jet balancing to study jet response • fb = (pTjet – pTg)/pTg • Run Ib (central): fb= -0.1980 ± 0.0017 • Run II (central): fb= -0.2379 ± 0.0028 • Plug region corrections in progress D fb = (4.0 ±0.4)%

  32. Measurements with jets • Jet shapes: • Narrower at higher ET • Calorimeter and tracking consistent • Herwig modeling OK 16 pb-1 used for this study

  33. Measurements with low Et m± 13 pb-1 • y trigger improved • pTm > 2.0 1.5GeV • Df > 5° 2.5° • Observed y rates are consistent with expected increase due the lowering of the thresholds No Silicon 100k y Centralmuons only 15 MeV with Silicon s = 21.6 MeV

  34. Add B scale correction Tune missing material ~20% Correct for material in GEANT Raw tracks Material & Momentum Calibration D0 • Use J/y’s to understand E-loss and B-field corrections • s(scale)/scale ~ 0.02% ! • Check with other known signals confirm with gee U 1S 2S 3S mm

  35. Meson mass measurements 18.4pb-1 BsJ/yf • B masses: • y(2S)J/y p+p- (control) • Bu J/y K+ • Bd J/y K0* (K0*K+p-) • Bs J/y f (fK+K-) More mass plots CDF 2002DPDG/s y(2S) 3686.43 ±0.54 0.9 Bu 5280.6 ±1.7 ±1.1 0.8 Bd 5279.8 ±1.9 ±1.4 0.2 Bs 5360.3 ±3.8 ± -2.1 BJ/yK 18.4pb-1 Bu 2.1 2.9

  36. B hadron lifetimes • J/y from B = 17% • Inclusive B lifetime with J/y’s Fit pseudo-ct = Lxyy*FMC*My/pTyct=458±10stat. ±11syst.mm (PDG: 469±4 mm) • Exclusive B+J/yK+lifetime ct=446 ±43stat. ±13syst.mm (PDG: 502±5 mm) # B ~ 154

  37. Trigger selects B’s via semileptonic decays ... 1910119 candidates 34922 candidates Run II trigger & silicon => ~3 yield/luminosity as in Run I (and likely to improve further with optimization) 61647 candidates

  38. SVT selects huge charm signals! 56320 D0 • L2 trigger on 2 tracks: • pt > 2 GeV • |D| > 100 mm (2 body) • |D| > 120 mm (multibody) • Large charm samples! • Will have O( 107 ) fully reconstructed decays in 2fb-1 data set • FOCUS = today’s standard for huge: 139K D0K-p+, 110K D+K-p+p+ • A substantial fraction comes from b decays (next slide) 25570 D±

  39. Fraction of charm from b decays • D mesons: • What fraction from B? • D0: 16.4-23.1% • D*+: 11.4-20.0% • D+: 11.3-17.3% • Ds+: 34.8-37.8% Range of fract. from B using two extreme resolutions functions: -single gaussian - parametrization from K0S sample Gaussian K0S

  40. Measure Ds, D+ mass difference 11.6 pb-1 • Ds± - D± mass difference • Both D  fp (fKK) • Dm=99.28±0.43±0.27 MeV • PDG: 99.2±0.5 MeV (CLEO2, E691) • Systematics dominated by background modeling ~2400 events ~1400 events Brand new CDF capability

  41. Measure Cabibbo-suppressed decay rates G(DKK)/G(DKp) = (11.17±0.48±0.98)% (PDG: 10.83±0.27) • Main systematic (8%): background subtraction (E687, E791, CLEO2) G(Dpp)/G(DKp) = (3.37±0.20±0.16)% (PDG: 3.76±0.17) • several ~2% systematics • This measurement has pushed the state of the art on modeling SVT sculpting--essential simulation tools for both B physics program and e.g. high-pT b-jet triggers Already comparable! Future? - CP violation - mixing - rare decays Monster Kp reflection here ...

  42. Toward Bs mixing! #B± = 56±12 constant multiplicative error ~ 15% (semileptonic) ~ 0.5% (hadronic) B+ D0p+ Need fully reconstructed (hadronic) decays to see past first couple of oscillation periods We observe hadronic B decays! Yields understood to ~20% level from detailed simulation • Next steps: • Reconstruct Bs Dsp, Dsfp • Flavor tagging algorithms • Exploit 3 SVX acceptance, SVT efficiency improvements

  43. 2-body hadronic B decays observed!! —sum BdKp BsKK Bdpp BsKp CDF II simulation • Yield lower than expected (now improved); S/N better than expected • With 2 fb-1 sample, measuring g to ~10º may be feasible, using Fleischer’s method of relating BsKK and Bdpp, and using b as input Width ~45MeV #B = 33±9 B  h+ h-

  44. Run II Physics Goals • Understanding Electroweak Symmetry Breaking • EW Measurements (MW, Mtop) • Higgs Boson Search • the Standard Model • SUSY • Study CP Violation and the CKM Matrix • Sin2b Measurement • Xs Measurement • Searches for New Phenomena

  45. Study CP Violation and CKM Matrix Bs mixing measurement is important for complete picture of the Unitary triangle.

  46. Int. luminosity (pb-1) CP Violation & CKM Matrix (cont.) • With data by next summer, • Bs mixing : SM prediction region fully covered. • dsin2b ~ 0.12 200 pb-1 (Summer 2003) 2 fb-1 end of 2003 CDF (Run I) BaBar (Winter 01) (Summer 01) Belle (Winter 01) (Summer 01) SM (sin2b )

  47. ヒッグス粒子探索についての記事 CERN研究所（ジュネーブ）でヒッグス粒子の候補事象が見えた。これが事実かどうかはフェルミ研究所での陽子反陽子衝突実験で明らかにできる。

  48. Electroweak Precision Measurements Tevatron Run I : Mtop = 174.3 +- 5.1 GeV/c2 MW = 80.452 +- 0.062 GeV/c2 Run IIa EW Meas : MHiggs <215 GeV @95%CL LEP II Higgs Searches : MHiggs > 113 GeV @95%CL LEP II Hint @ MHiggs= 115 GeV GW(from W high mass tail) 2.04 +- 0.15 GeV (CDF), 2.22 +- 0.17 GeV (D0) SM : 2.0937 +- 0.0025 GeV

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