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Some recent results from CDF

Some recent results from CDF. David Stuart U.C. Santa Barbara. October 24, 2005. Tevatron. pp pp+pp Eff ~ 10 7 /10 12 Repeat at 1Hz. 1 mile. 36 “bunches” each 10 11 protons/bunch 10 10 antiprotons/bunch 40 m m beam spot. Integrated Luminosity.

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Some recent results from CDF

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  1. Some recent results from CDF David Stuart U.C. Santa Barbara October 24, 2005

  2. Tevatron pppp+pp Eff ~ 107/1012 Repeat at 1Hz 1 mile 36 “bunches” each 1011 protons/bunch 1010 antiprotons/bunch 40mm beam spot .

  3. Integrated Luminosity

  4. CDF is pursuing a broad physics program • QCD • Top • B • EWK • New physics My interest is (mostly) in searches for new physics

  5. Searching for new phenomena • Why? • SM is incomplete • What? • Higgs • Supersymmetry • Extra generations • Extra forces • Extra dimensions • How? • SM++

  6. Searching for a Z’

  7. Electron Identification A typical di-jet event Atypical Zee event

  8. Tracking Detector Hadronic Calorimeter Electromagnetic calorimeter electron photon p+ p02 photons Electron Identification Require little energy in hadron calorimeter

  9. Tracking Detector Hadronic Calorimeter Electromagnetic calorimeter electron photon p+ p02 photons Electron Identification Require little energy around the EM cluster

  10. Tracking Detector Hadronic Calorimeter Electromagnetic calorimeter electron photon p+ p02 photons Electron Identification Require a matching track

  11. Tracking Detector Hadronic Calorimeter Electromagnetic calorimeter electron photon p+ p02 photons Electron Identification Require a matching track

  12. Tracking Detector Hadronic Calorimeter Electromagnetic calorimeter electron photon p+ p02 photons Electron Identification Require a matching track

  13. Electron Identification using a likelihood

  14. Electron Identification using a likelihood

  15. In fact, the electron id differs between “central” and “forward” electrons. Reduced tracking in the forward region calls for new techniques.

  16. e+ e+ e+ e- e- e- Particle Tracking Coverage proton antiproton

  17. Intermediate Silicon Layers

  18. B

  19. Forward Electron Tracking Algorithm • Form 2 seed tracks, • one of each sign, • from calorimeter & beam spot

  20. Forward Electron Tracking Algorithm • Form 2 seed tracks, • one of each sign, • from calorimeter & beam spot • Project into silicon • and attach hits using • standard silicon pattern recognition

  21. Forward Electron Tracking Algorithm • Form 2 seed tracks, • one of each sign, • from calorimeter & beam spot • Project into silicon • and attach hits using • standard silicon pattern recognition • Select best c2match

  22. Plug Alignment Align plug to COT using the subset of COT tracks which match plug electrons just above |h|=1. Then align silicon to the COT. COT Plug

  23. Plug Calorimeter Alignment Global Internal

  24. Obtain ≈1mm resolution

  25. Results from central electrons

  26. Results from central muons

  27. Limits hep-ex/0507104

  28. More recent results

  29. 2 + cosq 1+cos2q e+ 2 q p + + Forward-Backward Asymmetry e- Backward Forward p M [GeV/c2] e+e- Angular Distribution: sensitive to interference

  30. Limits of about 845 GeV/c2 for Z’ with SM couplings • Next, we could • look for other modes • Z’  t+t- • Z’  t t • exclude other models

  31. Strong Gravity • Geometrical factor generates TeV masses • m = m0e-kRp • where k is a scale of order the Planck scale. • kR≈12 generates the observed hierarchy. • Similarly, the graviton mass becomes • = MPle-kRp ≈ 1 TeV

  32. Strong Gravity Coupling  k/MPl Also mm, gg, tt, WW, HH, ZZ

  33. High Mass Diphoton Search Background is 2/3 dijets, 1/3 gg.

  34. Other di-boson modes in progress Several modes (eeee, eenn, eejj) with potentially very low backgrounds; Z mass constraint rejects background, and SM Z bosons are low pT.

  35. What else could lead to high pT Z bosons?

  36. What else could lead to high pT Z bosons?

  37. What else could lead to high pT Z bosons?

  38. Z bosons from GMSB Weak coupling could lead to long life.

  39. Z bosons from a 4th generation quark Weak coupling, Vtb’<<1, could lead to long life.

  40. Search for displaced Z’s • Search strategy • Select dimuons • from a Z • Require a good vertex • measurement (verify • efficiency with J/Y’s) • Opening angle cut • Require pT>30 for Z • Aim for simple selection to limit • model dependence. (aka, XYZ)

  41. Search for displaced Z’s • Search strategy • Select dimuons • from a Z • Require a good vertex • measurement (verify • efficiency with J/Y’s) • Opening angle cut • Require pT>30 for Z • Aim for simple selection to limit • model dependence. (aka, XYZ)

  42. Search for displaced Z’s • Search strategy • Select dimuons • from a Z • Require a good vertex • measurement (verify • efficiency with J/Y’s) • Opening angle cut • Require pT>30 for Z • Aim for simple selection to limit • model dependence. (I.e., XYZ)

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