D Higgs II

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DØ Higgs II
Gordon Watts
for the
collaboration
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Outline
Channels
HWW
SM, TopColor, 4th Generation
Hgg
SM, TopColor, Fermiphobic Higgs
HH--mmm-m-
Triplet models LR symmetric
bbhbbbb
SUSY High tan b
Current Status, Future Possibilities
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HWW
Production Decay
SM production primarily gluon fusion Analysis
looks for decay to lnln where le,m
Basic Analysis Cuts
Lepton ID (High pT, medium pT) Mass angle cuts
to eliminate Z g Missing Transverse Energy Cap
on Jet Activity (40 GeV)
Actual Cuts for Each Channel listed on web pages
Cross Section Limit
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HWW
In mass range 114-200 GeV/c2
sBR (eeem) lt 0.452.8 pb
sBR (mm) lt 0.20.7 pb
This will probably not be a SM search in Run II
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HWW Expectations
Efficiency
Currently x2 less than Higgs/SUSY workgroup
result Mostly in Lepton ID Internal version of
analysis has much better ID efficiency using more
advanced tools
Not at the Tevatron
SM
Non-SM
Enhanced coupling for WW in top color and 4th
generation models.
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Hgg
SM
Rate is too low to be observed at the Tevatron
non-SM

• Models with suppressed fermion-Higgs coupling
• Some Universal ED models

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Hgg
Assume SM Higgs Production Cross-Section
Photon ID, Apply Sliding Mass Window Cut
Limit
DØ RunII Preliminary
Mgg
DØ RunII Preliminary
Data
SM BG Sum
DY
Events/8 GeV
QCD
Top Color Higgs
Assume BR(Hgg) 1
d(Mgg) 2.5 GeV/c2
Luminosity 51.8 pb-1
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Hgg Expectations
Higgs/SUSY WGR
With 50 pb-1 and BR1 we expected a larger limit
Working on bringing down the jet-photon
misidentification rate
Top Color Higgs
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H Production
qqZ /gHH--

• Higgs Triplet Model
• LR Symmetric versions
• Attractive as alternative to SUSY (CP, Mn)
• Sharply falling s at the Tevatron

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H Production

• DØ look in the muon channel
• e, t(harder) possible

• Requires gt2 isolated m
• opening angle cuts (Z)
• 2 m of like sign

(preselection)
Analysis Cuts
e (0.47-0.50)0.01 for MH 80-200 GeV/c2
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H Results

• Luminosity 107 pb-1
• M(H) gt 95 GeV _at_ 95 c.l. (right-handed)
• M(H) gt 116 GeV _at_ 95 c.l. (left-handed)
• worlds best limit

• Efficiency will improve with improved lepton ID
• Under Verification
• Cross section is sharply falling
• 80 GeV/c2, 31 events
• 200 GeV/c2, 0.48 events

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SUSY Large tan b Search
Promising SUSY channel at the Higgs/SUSY WS
tanb
Since then

• Great deal of theory work
• NLO cross sections almost done
• Generation parameters better understood
• bh channel better developed

CP-odd HiggsProduction
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SUSY Large tan b Search

• Jet ID
• b-tagging
• b-tag e3
• dijet mass window cut
• HF Jet Corrections

CompHEP Pythia MCmh 120 GeV/c2
Higgs WG DØ Expectations
Coming soon to a conference near you
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If we didnt show this
Indirect Higgs Search
LEPEWWG Sum03
Further Constrain the SM
dMt lt 2.5 GeV/c2
Currently 5.1 GeV/c2
dMW lt 40 MeV/c2
Currently 59 MeV/c2
We have a long way to go
these are combined, Run II predictions are per
experiment
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Workshop
Plots Efficiencies
The Public Higgs pages contain most plots and
many more efficiency numbers www-d0.fnal.gov
At Work Physics Groups Higgs Public
Documents. Look at the 2003 result links.
Details
Anyone here from DØ has access to our internal
notes and should be able to answer further
questions during this conference!
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Conclusions

• Initial results for gg, WW, and HH-- shown.
• Analysis for hbb forthcoming. Other non-SM
  analyses being worked on
• Charged Higgs, taus, etc.
• All results shown based on old version of
  analysis software
• Results to be released for winter conferences
  should have improved understanding of detector.
• Tracking and b-tagging in particular.
• Data Set Size
• About 100 pb-1 of data shown.
• Winter conferences should have over 200 pb-1!
• No detailed study of TeV Run II Reach
• Run 2b Si cancellation strongly affects any
  analysis dependent on tracking (btagging,
  electron identification, muon identification,
  etc).
• DØ is still studying how best to optimize the new
  situation.
• Stay tuned!