CDF Searches for New and Exotic Physics

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CDF Searches for New and Exotic Physics

• Steven Worm
• Rutgers University

The TeVatron Connection, August 10 2004, Fermi
National Laboratory
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New Results from CDF

• Supersymmetry pb-1
• GMSB diphotons 202
• Gluino ? sbottom bottom 156
• Large Extra Dimensions
• LED from diphotons 345
• Leptoquarks
• LQ decays to e?jj, eejj, µ?jj 203
• Technicolor
• Techni-?, techni-p 162
• Compositeness
• e? e? 200
• High mass Drell Yan
• Z ? tt 195
• Even Weirder stuff
• Dirac Monopoles 25

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Excited electrons e

• Search for an excited or exotic electron in pp ?
  e e ? e? e
• Select events with ee? final state
• Look for resonances in an e? pair
• Backgrounds small mainly Z? but also Zj, WZ,
  multijet, ??j, Wjj
• Expected in Compositeness models
• Cross section parameterized by e mass and
  compositeness scale (?)

contact interaction
(K. Hagiwara et al, Z.Phys C29115)
gauge mediated
(U. Baur, Phys Rev D42, 3)
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Excited electrons e
Contact interaction Me gt 889 GeV/c2

• In 200 pb-1, expect 3 events, see 3 events
• Limits for contact interaction Me/? vs. Me
  shown at left
• Gauge mediated result plotted as a function of
  f/? vs. Me at right
• For Me ?, Me gt889 GeV/c2 (contact) or gt208
  GeV/c2 (gauge)

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Di-photon and Large Extra Dimensions

• Search high-mass ?? events for new physics (ie RS
  Gravitons)
• Backgrounds from
• Standard model diphoton
• Misidentifications ?j or jj where jet gives a
  hard p0
• Highest mass event m(??) 405 GeV/c2

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Di-photon and Large Extra Dimensions
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Di-photons and Missing Energy

• Search for events with ?? Missing Energy (MET)
• Gauge Mediated SUSY N1 ? ?G, so pp ? X
  neutralinos ? ??MET
• Event selection
• Two central photons, ET gt 13 GeV
• Understanding MET is important
• Best limit expected at
• MET gt 45 GeV
• Backgrounds include
• QCD fake MET
• e faking ?
• Cosmic rays, beam halo

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Di-photons and GMSB

• Expect 0.6 events and see 0 events in 202 pb-1

M(C1) gt 168 GeV/c2 95 CL M(N1) gt 93 GeV/c2
95 CL
T.Plehn et al, PRL 83 (1999) 3780-3
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Leptoquarks

• Leptoquarks appear in many SM extensions
  including
• SU(5), SU(4) Pati-Salam models, Technicolor,
  Compositeness
• LQ carry both lepton and baryon number
• Finding leptoquarks at the TeVatron
• Pair-produced at the TeVatron predominantly via
  gg fusion
• Produce isolated high-pT leptons and 2jets
• TeVatron signatures include lljj, l?jj, and ??jj
• Make use of kinematics of LQ events large SjetET
  and SlET

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Leptoquarks 1st Generation

• ?

m(LQ) gt 230 GeV/c2 95 CL m(LQ) gt 176
GeV/c2 95 CL
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Leptoquarks 2nd Generation

• Signature is µµ 2 jets
• Make use of tight dimuon data and muon track
• Backgrounds include QCD (fakes), top, and Z2jets
• Expect 3.15 1.17 events in 198 pb-1, see 2
  events
• Limits set assuming ß BR(LQ?µq) 1

M(LQ2) gt 240GeV/c2 95 CL
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Technicolor

• Can search for Technicolor in many signatures
• New search explores same signature as SM Higgs
  (l?bb)

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Technicolor
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Gluino ? sbottom bottom

• Large production xsection at the TeVatron,
  sbottom may be light
• Assume BR(b1 ? b?10) 100, R-parity conserved
• Assume m(g) gt m(b1) gt m(?10), m(t) m(?1 ) gt
  m(b1)
• Exploit b tagging and kinematics of events
• 3 jets gt 15 GeV, ? lt 2
• MET gt 35 GeV
• ?f(MET,jets) gt 40º
• b-jet secondary vertex tag
• Backgrounds QCD, W/Zjets, Diboson, Top

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Gluino ? sbottom bottom

• Single and double b-tagged events in 156 pb-1 of
  data

Expect 16.4 3.7 Expect 2.6 0.7 Observe
21 Observe 4
Perform counting experiment
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Gluino ? sbottom bottom

• For ?M(gluino, sbottom) 60 GeV/ c2
• Exclude 20.6 single tag events at 95 CL
• Exclude 8.7 double tag events at 95 CL

Large exclusion region added in sbottom-gluino
plane
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High-mass Drell Yan Z ? tt

• Tau physics important for high tanß SUSY
• Tau finding algorithm much
• improved and tuned
• Shrinking cone implemented
• p0 reconstruction improved

Checks with W ? t? look good!
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Z ? tt

• Look in high mass region for new physics
• M(MET,t,t) gt 120 GeV
• MET gt 15 GeV
• ?f(MET, tl) gt 30º
• counting experiment
• Expect 2.83 0.39 events, see 4
• Exclude Z lt 394 GeV/c2 95 CL
• (Z with SM couplings)

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Dirac Monopoles

• Truly Exotic signature
• Large pulses in Time of Flight (TOF)
• Large ionization in drift chamber (COT)
• No curvature in r-phi
• Curvature in r-z (not used in analysis)
• Developed a dedicated trigger for Monopoles

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Monopole Search Results

• Drell-Yan like cross section

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Conclusions
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Bs ? µµ- at CDF
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