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Exploring New Physics: Recent Results from CDF at UC Santa Barbara

This report presents recent results from the CDF collaboration at UC Santa Barbara, discussing high-energy physics experiments conducted at the Tevatron. With an integrated luminosity of approximately 107/1012 and a 1Hz repetition rate, the findings include searches for new phenomena that challenge the Standard Model (SM). Areas of focus include the Higgs boson, supersymmetry, extra generations, forces, dimensions, and the Z' particle. The methodologies involve electron identification and tracking algorithms, highlighting the intricate experimental setups and data analysis essential for discovering potential new physics.

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Exploring New Physics: Recent Results from CDF at UC Santa Barbara

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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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