1 / 33

Exploring Heavy Flavor Physics at the Tevatron: Latest Results and Future Directions

Dive into the world of heavy flavor physics at the Tevatron with insights on production measurements, decay processes, and new physics implications. Discover the complexities of B meson studies and rare decays in this enlightening review.

bockd
Download Presentation

Exploring Heavy Flavor Physics at the Tevatron: Latest Results and Future Directions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. B Physics at the Tevatron Steve Nahn-Yale University/CDF Ambassador for the CDF and DØ Collaborations Mandate: “..The invited session talks are 30+6 minute review talks designed to highlight and advertise the many short talks in the contributed sessions” “many”  30 in this case!

  2. Plan • Short Course in Heavy Flavor Physics @ TeV • Excellent intro by P. Burchat in A0 • Heavy Flavor Results Smorgasbord • Production measurements • Decays • Lifetimes and Mixing results presented at APS/DPF `05. • Highlight results presented at APS/DPF `05. • Where other results exist, not discussed • Attempt at equal exposure for each experiment • Details? GO TO THE SESSIONS! other results S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  3. The Tevatron is a Dirty B factory • Wealth of B Physics • Only ~5% reconstructable • Zoo of b hadrons: B0, B+, Bs, Bc, b,  b, B** • But • O(103) higher • Hard to find “other b” • ~ 30% acceptance • Boost not large Lots going on in Si detector S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  4. Both detectors Silicon microvertex detectors Central tracking in Solenoid High rate trigger/DAQ system Calorimeter & muon systems Require all-charged final states CDF silicon detector installation Detectors • DØ • Excellent electron & muon ID • Excellent tracking acceptance • CDF • Particle ID (TOF and dE/dx) • Excellent mass resolution DØ fiber tracker installation S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  5. Datasets • After slow start, Tevatron excelling • dLint/dt increasing • Data on tape: • ~500 pb-1 2002-2004 • ~ +100 pb-1 2005 • DØ: • ~220-500 pb-1 in these results • CDF: • ~240-360 pb-1 in these results S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  6. B y x Triggering: Heavy Flavor  Tape • Hb X(J/  ) • 2 track  matches within m window • Hb lnX • Lepton signature in pT range • Hb hadrons • Displaced tracks and vertex S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  7. Heavy Flavor Analysis • Selection techniques • Quality objects • Kinematics • Consistent vertex structure • Reference channels • Relative Branching Ratios • Calibrate algorithms • Optimize Selection • Simulation • Detector effects • Other resonance pollution • Algorithms • Simultaneous likelihood fits • PID for statistical separation Golden Bs Modes Ds+D++ S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  8. Production of Bc Mesons • Least well known B meson • Theory: Largest mass, shortest lifetime • 20  6 events in Run 1 S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  9. Bc J/l  S J8: CDF: Hartz & Aoki DØ: Ay • B J/ K as reference • Background suppression KEY • Fake J/ or lepton • b [J/] b [ l ] • CDF: separate cross section ratio for l = m ,e • Combined lifetime next • DØ: mass and lifetime in m • Moving to Bc J/ _ S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  10. Something new: X(3872) • Observed by Belle, confirmed by TeV, but what is it? • Charmonium? • DD “molecule”? • Seen in XJ/ at TeV • (2S) J/ is reference channel † Addition of m(J/) by SN S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  11. Further X Studies • DØ: Measure fractional production versus kinematic quantities • Compare with (2S) • “Charmonium”-like • CDF: Examine the m spectrum versus theory • Rules out some, but none perfect S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  12. Other Heavy Flavor Production • B**(L=1) B • B J/K and D modes • Important to understand impact for mixing • Cross section Bl DX • Complement to J / mode • J/ Spin Alignment • Test “Octet” Production model S Z8: CDF Pursley S Z8: CDF Kraus DØ S Z8: CDF Kim S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  13. Heavy Flavor Decays • New Modes • Test against theory predictions • Add statistics for mother particle studies • Help understand background in other analyses • Rare decays limit contributions New Physics • CP Violation in Decay • cf. Babar … S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  14. Plethora of new channels S Z8: CDF Iyutin S Z8: CDF De Lorenzo S J8: CDF Kong • Bs(2S) • BDsD • Bs ~40 events S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  15. Semileptonic decays to excited states • BD**mn • BsDs**mn • Ds**D*KS S Z8: DØ Tsybychev S C8: DØ Rieger S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  16. Rare Decays • FCNC Charm Decays cu • Df  relative to Ds • Precusor to nonresonant study • Bsmm BrSM ~ 10-10 New Physics! • 4.3 ±1.2 expected, 4 seen • Bsmm • Sensitivity: S J9: DØ Casey CDF S J8: DØ Bernhard S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  17. Lifetimes and Mixing • B mixing  CKM • Prereq to Mixing • Test HQE theory C. Tarantino, hep-ph/0310241 Oct 2003 LO NLO Experiment Theory S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  18. S Z8: CDF Miles Clark S U12: CDF Da Ronco S J8: DØ Casey Heavy Flavor Lifetimes • Tevatron Industry • Typically Simultaneous Mass and Lifetime fit S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  19. Example Lifetimes: Bs • DØ BsDsl  • Ds   • Overcome  w/simulation • CDF Bs Ds • Ds   • Trigger Bias S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  20. Bs Lifetime Difference DG S H8: DØ Welty • BsJ/ • B VV, mixture of CP even/odd separate by angular analysis • Combine two-lifetime fit + angular DGs=GH-GL • SM DGs/Gs=0.120.06 (Dunietz, Fleischer & Nierste) • Indirect Measurement of Dms S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  21. Direct B mixing in a nutshell • Measure Asymmetry • Determine “time” of Decay: st= Proper lifetime resolution • measure decay length, apply boost • Sort the mixed from unmixed via b charge at production and decay • S = Signal Yield  efficiency for making a determination • D = “Dilution” = (2P-1); P = Probability of correct assignment S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  22. S H8: CDF Giurgiu and Belloni U 12: DØ Naimuddin and Krop Calibration on Bd • Know the right answer • Tests Fitting Mechanism • Calibrates Tagging • Much higher statistics S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  23. S J8: CDF Giurgiu U 12: DØ Naimuddin/Krop Bs Mixing Results • Amplitude Scan • Fourier Transform into Dm space only floating A • A = 1 for true Dm, 0 else • Limit A+1.645sA = 1 • Sensitivity  1.645sA = 1 • NIM A384(1997) p.491 ff. S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  24. S U12: “Tevatron techniques in B Physics” CDF and DØ Potential in Bs Mixing • Statistics: Ifgain factor of 4 from • Opposite and Same Side Kaon Tagging (CDF), Electron Tagging (DØ) • More Channels, More Luminosity, Smarter Triggers • Multivariate Tagging approach • And If gain 20% on Proper Time resolution • Event By Event Primary Vertexing • Better st understanding 4 Statistics +20% Resolution S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  25. Whew! • Tremendous amount of Heavy Flavor activity going on at the Tevatron • Squeezing Physics from data samples available nowhere else • Manpower limited • Most of the Luminosity still to come • We’re at 0.8, expect >4 fb-1 total • Crucial “Run 2b” upgrades done this fall • CDF: Track Trigger, Displaced Vertex Trigger … • DØ: Inner Silicon Layer, Track Trigger … S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  26. Backup Slides S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  27. Bc J/ • Fully reconstructed • Good mass resolution • Is it significant? • Analysis done “blind” • Loosen cuts, look for partial reconstructed Bc in low mass sideband • compare d0() w.r.t. J/  • See similar excess in B+ S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  28. Pentaquark Production? S Y12: CDF Field • [5 quark bound state]  Baryon-Meson • Observed elsewhere: Can they be seen at TeV? • same trigger/kinematic range as Heavy Flavor • many reference decays cDp m 3.1 GeV/c2 Reference None Seen S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  29. Im Re Standard Model Mixing • In Standard Model, Mixing from CKM matrix • Flavor states not mass eigenstates on the quark level • CP Violation inherent with 3 generations • Comes in through loops, akin to New Physics • Mixing sensitive to other particles in loop s b W t t _ s b _ W _ S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  30. Mixing Channels of interest • Decay chain tags the flavor • Lepton/Pion from b decay • Hadronic Decays • Fully reconstructed  excellent resolution • Trigger on pair of 2 GeV displaced tracks • Semi-leptonic decays • Higher statistics, but miss neutrino • Trigger on 2 GeV displaced track and 4 GeV lepton • Collect multiple Ds decays S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  31. S U12: “Tevatron techniques in B Physics” (Now!) CDF and DØ Candidate (Same) Side Opposite Side Fragmentation track Hb p D Bs K p Ds K Production Flavor • Look at associated particles • Other b decay • Lepton Charge • Charge of B decay products: • Kaon Charge • Nearest charged track • Vacuum gives net charge 0 S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  32. Current World Knowledge • dominated by “B factories” • Designed specifically for this purpose • not accessible at B factories, have world ave. • Limit from and S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

  33. Measuring a limit: Amplitude Scan • msmeasurement is “blinded” • Study all systematics, sensitivity without looking at the answer • Looks like a limit  Amplitude Scan • Fix tagging parameters from from md measurement • Add Amplitude factor to the oscillation term, scan ms space • NIM A384(1997) p.491-505 • Check for md: S Nahn - "B Physics at the Tevatron" APS/DPF 05 Tampa

More Related