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Selected D Ø Physics Results for ICHEP 2006

Selected D Ø Physics Results for ICHEP 2006 . Andrzej Zieminski Indiana University for the Collaboration W&C, Fermilab, June 21, 2006. Approach. concentrate on results never presented before to this audience, many approved this week.

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Selected D Ø Physics Results for ICHEP 2006

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  1. Selected DØ Physics Results for ICHEP 2006 Andrzej Zieminski Indiana University for the Collaboration W&C,Fermilab, June 21, 2006

  2. Approach • concentrate on results never presented before to this audience, many approved this week. • results will be sorted by physics groups • only a fraction of the results will be presented • a comprehensive list of all results improved, finalized and preliminary since Winter Confs. will be provided • Recent W&C from D0: • Guennadi Borrisov, B-states & dimuon asymm. Mar. 3 • Sergei Burdin, Bs mixing Mar. 24 • Gregorio Bernardi, Higgs searches May 5 • Patrice Verdier, SUSY results June 9 • Andrew Askew, Diboson physics June 23 D0 Results for ICHEP

  3. D0 Detector & its Performance Multipurpose. Silicon microvertex tracker Central Fiber Tracker Axial solenoid Muon ID; || < 2 Tracking acceptance || < 3 D0 Results for ICHEP

  4. QCD/EWK physics: recent analyses • Inclusive jet cross sections 0.8 fb-1 • W asymmetry0.2 fb-1 • Zgx-section 0.4 fb-1 • X Zg searches 0.4 fb-1 • Zg x-section & anomalous couplings eeg (mmg) ~ 1 fb-1 - WW x-section 0.2 fb-1 • WW anomalous couplings 0.2 fb-1 • First evidence for WZ production 0.8 fb-1 • Z pT measurement (ee)0.8 fb-1 D0 Results for ICHEP

  5. Theory @NLO is reliable (±10%)  Sensitivity to PDFs  Unique: High-x Gluon Run II: s increased x5 at pT=600 GeV  Sensitive to New Physics: Compositeness, LED, …(?)… Inclusive jet cross sections DØ - midpoint cone algorithm D0 Results for ICHEP

  6. Run I and Run II so far… Good agreement of theory and data over large pT & √s range D0 Results for ICHEP

  7. W Charge Asymmetry Typically the u quark carries more of the proton momentum  W+ is boosted in the direction of the proton Isolated m, pT > 20 GeV, MET > 20 GeV, MT > 40 GeV. Charge mis-id = 0.01% (Z-data, m momentum measured twice) Yellow band: CTEQ uncertainty Blue MRST02 central value L=230pb-1 0.005 < x < 0.3 D0 Results for ICHEP

  8. WZ production Direct probe of the WWZ Trilinear Vertex • Select 2 leptons (ee,mm) pT > 15 GeV. • MET > 20 GeV • Additional high pT lepton • Reject top events by ETHAD< 50 GeV. • Instrumental bkgd: Z+j from data • Physics bkgd: ZZ, Top, W+DY • = 3.9 +1.9-1.5 pb sSM = 3.7 ± 0.3 pb First evidence for WZ production (3.3s) D0 Results for ICHEP

  9. Top physics: recent analyses • Top pair x-section • All jetslifetime tag & topol 370 pb-1 • lepton+track & e+m lifetime tag & topol 370 pb-1 • Top Quark mass - lepton+jetsMatrix, in situ JES , b- tag 370 pb-1 • lepton+jetsMatrix, in situ JES , topology 370 pb-1 • lepton+jetsIdeogram , b-tag & topology 370 pb-1 • em Matrix weighting 835 pb-1 • emNeutrino weighting 835 pb-1 • Other top properties • Right-handed W’s 370 pb-1 • W’ search 230 pb-1 D0 Results for ICHEP

  10. All jet + Data Pythia tt 175GeV High yield, high BG M(jj) M(bjj) Data with final selection (with b-tagging) Background From data Background substracted 360/pb D0 Results for ICHEP

  11. Summary of RunII top cross section results D0 Results for ICHEP

  12. l W+ b-jet n t t W- jet Mjj(W) jet b-jet Top Mass in lepton+jets channel using ideogram method Cuts: pt>20 GeV, MET>20 GeV, ≥4j ( pt>20, |h|<2.5) Ideogram method: Event by event likelihood based on kinematic fit. Includes all possible assignments of jets, and possibility of background, Lifetime-based id of b-jets when available JES in situ calibration D0 Results for ICHEP

  13. Top mass measurements in em 835 pb-1 Unconstrained system: 2 neutrinos, 18 kinem. Quantities, 14 measured+3 constraints 28 events seen, expected: 20.2±2.7 ttem, 4.4±2.6 bkg (WW, Ztt, fake e) Matrix element weighting: For each event find mpeak for which solution weight is maximum Compare observed mpeak distributions to combined signal and bkgd templates • : Neutrino weighting technique: Start by ignoring observed missing ET Assume top mass and η for each n & extract n 4-momenta. Weight each solution Event weight vector – 3 different methods Max likelihood fit of weight vectors to MC templates D0 Results for ICHEP

  14. Summary of top mass measurements D0 Results for ICHEP

  15. B - physics recent analyses All based on ~1 fb-1 data • Bs mixing in Bs Ds-m+X (Ds-fp) PRL 97 (2006) 021802, July 14 • Bs mixing in Bs Ds-m+X (Ds-  K*0K-) • Bs mixing in Bs Ds-e+X (Ds-fp) • Lifetime difference and Mixing Phase in the Bs system • Time-integrated asymmetry in semileptonic Bs decays • CP – violation parameter of B0 mixing from dimuon charge asymmetry • BF(Bs®Ds(*)Ds(*)) • Bd** production fractions • Bd** mass splitting • direct observation of Bs** • measurement of Bs®Ds** m n • limit on D+®p+m+m- Either first or best measurements D0 Results for ICHEP

  16. Bs - an entangled system • Bssystem is strongly mixed; • Two physical statesBsH(heavy) andBsL (light) have distinct masses and lifetimes: M12andΓ12are elements of complex mass matrix (M - iΓ/2) ofBssystem; s- CP violating phase; s(SM)= O(|Vus|2 mc2/mb2) ~ 5·10-3 = 0.3º D0 Results for ICHEP

  17. Dms limit from Log Likelihood Scan • Resolution • K-factor variation • BR (BsDsX) • VPDL model • BR (BsDsDs) Systematic PRL 97 (2006)021802 17 < Dms < 21 ps-1 @ 90% CL D0 Results for ICHEP

  18. Measurement of DG and s • DØ has measured sin three different processes: • From the time dependence of polarization amplitudes in • From time-integrated like-signdi-muon charge asymmetry: • From time-integrated charge asymmetry of Bs μνDs(Ds fp ; fKK)decay: D0 Results for ICHEP

  19. Lifetime Difference and Mixing Phase from BsJ/y (m+m-) f(K+K-) untagged decay • Final state is a mixture of CP-even and CP-odd components; • They produce different angular distributions of polarization amplitudes • A0, A|| (CP-even) and • A (CP-odd); • Time evolution of these amplitudes depends on lifetime differenceΔΓ(Bs)& CP-violation phases D0 Results for ICHEP

  20.  vs c D0 Results for ICHEP

  21. Dimuon Charged Asymmetry • Charge asymmetry of muons from B decays depends on the CP violation phase: • Non-zero Asl corresponds to CP violation in mixing; • D0 has measured dimuon charge asymmetry - better control of systematics: D0 Results for ICHEP

  22. Dimuon events in DØ • ~ 5 M like-sign dimuon events collected (1 fb-1) ; • Excellent muon system with very low punch-through; • Strong suppression of cosmic background; • Regular reversal of magnets polarities - reduced detector systematics; • Result (Both Bd and Bs contribute) : D0 Results for ICHEP

  23. Asymmetry in semileptonic Bs decays ~27K (μDs) events • ASLs can also be obtained from time-integrated charge asymmetry in semileptonic decays BsμνDs: • Large sample of decays BsμνDs with Dsφπwas collected under different conditions M(KKp) D0 Results for ICHEP

  24. ΔΓsversusfs Both DØ results on ASL can be combined together: • ASLd value from B-factories DMs = 17.3 ± 0.3 ps-1 (CDF) DGs tan(fs) = -0.01 ± 0.16 ps-1 D0 Results for ICHEP

  25.  vs s D0 Results for ICHEP

  26. Combining results for the Bs system D0 Results for ICHEP

  27. SM Higgs Production and Decays decays production Search strategy: MH < 135 GeV: associated production WH and ZH with Hbb decay Backgrounds: top, Wbb, Zbb…complement it with WWW* and WW* MH >135 GeV: gg H production with decay to WW* Backgrounds: WW, DY, WZ, ZZ, tt, tW,  D0 Results for ICHEP

  28. Higgs group recent results • H WW* (mm channel) 0.9 fb -1 • H WW* (ee and em channels)0.9 fb -1 • WH  WWW* 0.4fb-1 • WH  mn bb 0.4 fb-1 • WH  en bb 0.4 fb -1 • ZH  mm bb 0.3 fb-1 • ZH  ee bb 0.4 fb-1 • ZH  nn bb • Z  bb 0.3 fb-1 • Z + n jets x-section 0.3 fb-1 • hb/hbb 0.9 fb-1 • bh b tt 0.3 fb-1 • Techniparticle search using NN 0.4 fb-1 • rT W(mn) + PT 0.4 fb-1 • rT  W(en) + PT 0.4 fb-1 SM MSSM Technicolor D0 Results for ICHEP

  29. Search for H  WW* lnln Resultsbased on ~ 950 pb-1 : - ee, em channels at Moriond - mm channel in internal review 95% C.L. limits using CLs method 4th Generation Model starts to be excluded D0 Results for ICHEP

  30. Search for H  WW* mnmn D0 Results for ICHEP

  31. Combined Higgs boson Search 14independent channels have been combined, taking into account correlated & uncorr. systematics • WH (e) ST, DT • WH (m) ST,DT • WH ( l ) ST DT • ZH (nn) ST,DT • WWW (ee,em,mm) • WW (ee,em, mm) • ZH (ee, mm) will be added soon We have used the CLs (LEP) Method D0 Results for ICHEP

  32. SM Higgs Combined Limit • NNLO cross sections for HWW* • same results as those shown at Moriond Data/SM = ~15 at 115 GeV ~ 5 at 160 GeV D0 Results for ICHEP

  33. Technicolor searches (e) Cut-based & Neural Network p 110 GeV r 210 GeV D0 Results for ICHEP

  34. Beyond the Standard Model Enlarged gauge group  Z’, W’ Alternative EWSB mechanisms (TC, Little Higgs) Relate quarks and Leptons  Leptoquarks Supersymmetry andincludes graviton(Supergravity) Extra dimensions Compositeness… D0 Results for ICHEP

  35. New Phenomena recent results SUSY Searches for: Associated production of Charginos and Neutralinos eel 0.9 fb-1 Associated production of Charginos and Neutralinos SS dim0.9 fb-1 GMSB in gamma gamma and MET ~1 fb-1 R-Parity Violating SUSY via LLE Couplings ~0.4 fb-1 Resonant 2nd Genereation Slepton Production ~0.4 fb-1 Scalar Top Pair production in Acoplanar Jet Topology ~0.3 fb-1 Non-SUSY: Excited Muons 0.4 fb-1 3rd generation leptoquarks 0.4 fb-1 Randall-Sundrum gravitons ~ 1 fb-1 W’ en ~1 fb-1 D0 Results for ICHEP

  36. c q ~ t1 ~ 0 ~ c t1 q ~ 0 Scalar Top in the Acoplanar Jet Topology scenario stop NLSP and  LSP with stc (FCNC) (relevant as long as m(st) < m(b)+m(W)+m()) • 2 jets pT >20 (40) GeV ≥1 c-jet (soft tag) + missing ET (optimized for various m(st),m()) • Main backgrounds: W/Z+jets Result: e.g. Mst = 130 Gev MΧ =50 GeV Data: 60 evts Bkgd: 60±13 The highest excluded stop mass is : D0 Results for ICHEP

  37. Charginos and Neutralinos in Trilepton channels • “Golden” SUSY signature but: • - low cross sections ( BR) • - soft leptons • - taus (at large tan) • Needs large integrated luminosity • Combine various final states • General strategy: • Two isolated (rather soft) e or  • Missing ET () • channel-dependent cuts (e.g. anti Z, ) • An isolated third lepton or track (sensitive to ’s), or • Two same sign leptons • Main backgrounds: DY, WW, WZ, W , mis-ID D0 Results for ICHEP

  38. Trileptonslike-sign dim eel channel Missing ET pT(3) Missing ET x pT(2) D0 Results for ICHEP

  39. Trileptons – combined results Chargino mass limit of 140 GeV in the ``3l-max’’ scenario (previous limit 116 GeV) D0 Results for ICHEP

  40. 3rd generation leptoquark searches • 2 approaches: • double lifetime based b-tag • - m + single b-tag •  No excess of evts over SM mLQ > 219 GeV, if B(LQnb)=1 D0 Results for ICHEP

  41. Search for New Heavy Charged Gauge Boson, W’  en • Additional gauge bosons introduced in • Left-Right-Symmetric model • GUT models … Previous limit: m W’ < 800 GeV (W’qq, D0-Run I) • Event selection: • Isolated e ET > 30 GeV • MET > 30 GeV • 0.7 <ET/MET <1.3 etc • Normalization to transverse mass spectrum in the • 60 < mT < 140 GeV region D0 Results for ICHEP

  42. W’  en Limit Shape of mass spectrum + assuming: no mixing angle, g’=g, and same CKM e.g. mT >150 GeV cut: 630 evts bkg: 623±18(stat) ±79(syst) ( 573 Wen, 10 Wtn, 5 WW (Z), 24 QCD ) m W’ > 965 GeV @ 95% CL D0 Results for ICHEP

  43. Summary • Steady progress in QCD/EWK/top physics 3.3s evidence for WZ production • First results on CPV angle df in Bs system from BsJ/y f decays and semileptonic asymmetries • Higgs limits pushed down, factor 4-6 above SM around MH = 160 GeV • New limits for BSM searches: W’, SUSY, Technicolor, 3rd generation leptoquarks, … • Several additional results in internal review for ICHEP • THANK YOU, FERMILAB !!! D0 Results for ICHEP

  44. BACKUP SLIDES D0 Results for ICHEP

  45. Bs - an entangled system D0 Results for ICHEP

  46. Asymmetry  df Previous D0 measurement: asymmetry in like-sign dimuon production. After removing detector translates into: Using CDF Dms measurement, B-factories Asld, fs fraction in b-fragm. one gets: Asls = - 0.006 ± 0.009 Asls = DG/Dm tan(df)(U. Nierste: hep-ph/0406300) D0 Results for ICHEP

  47. Select Bs Ds-m+X (Ds-fp, fK+K) evnts; Separate Physics asymmetry A from the detector effectsby finding #s of events with different muon charges (q), separately for diff. toroid polarities (b) and psedorapidities (g): 8 measurements, 8 unknowns:  A = Physics Asymmetry Find processes contributing to A Obtain CP violation asymmetry AsSL; Analysis Strategy D0 Results for ICHEP

  48. Lifetime Difference and Mixing Phase in the Bs System • BsJ/y (m+m-) f(K+K-) untagged decay • PVV decay: 3 amplitudes, 3 decay angles • Fit the time and angular dependence for: • - decay rate difference DG between • L(light) and B(heavy) B states • mean decay rate • allow for CP violatation df • df = 0 mass eigenstates = CP eigentates D0 Results for ICHEP

  49. Time - integrated untagged decay rate asymmetry in semileptonic Bs decays: e.g.Bs Ds-m+X (Ds-fp, fK+K-) ≈ ½ =½ = ½ AsSL Experimentally: SM predicts: Small SM value of AsSL gives a chance to observe possible contribution of new physics For various extensions of SM, an enhancement of ASL can be considerable, up to 0.5x10-2, which corresponds to sindf~1 D0 Results for ICHEP

  50. Bs -- M12 plane D0 Results for ICHEP

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