dØ higgs ii gordon watts for the collaboration. 2 gordon watts (uw seattle) win’2003 10/07/2003...
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2Gordon Watts (UW Seattle) WIN’2003 10/07/2003
Outline
Channels
HWW*
H
H++H--++--
bbhbbbb
SM, TopColor, 4th Generation SM, TopColor, Fermiphobic Higgs
Triplet models; LR symmetricSUSY High tan
Current Status, Future PossibilitiesCurrent Status, Future Possibilities
3Gordon Watts (UW Seattle) WIN’2003 10/07/2003
HWW*
Production & Decay
SM production primarily gluon fusionAnalysis looks for decay to ll where l=e,
Lepton ID (High pT, medium pT)Mass & angle cuts to eliminate Z &
Missing Transverse EnergyCap on Jet Activity (40 GeV)
Cross Section Limit
Actual Cuts for Each Channel listed on web pages
Actual Cuts for Each Channel listed on web pages
Basic Analysis Cuts
4Gordon Watts (UW Seattle) WIN’2003 10/07/2003
HWW*
ee e Lumi 118 pb-1 102 pb-1 114 pb-1
Obs 0 1 1
Expected
1.1±0.8 0.9±0.5 0.95±0.12
BR (ee+e) < 0.45–2.8 pbBR () < 0.2–0.7 pb
This will probably not be a SM search in Run II
This will probably not be a SM search in Run II
In mass range 114-200 GeV/c2
5Gordon Watts (UW Seattle) WIN’2003 10/07/2003
HWW* Expectations
Enhanced coupling for WW in top color and 4th generation models.
EfficiencyCurrently x2 less than Higgs/SUSY workgroup resultMostly in Lepton ID
Internal version of analysis has much better ID efficiency using more advanced toolsSM Not at the Tevatron
Non-SM
6Gordon Watts (UW Seattle) WIN’2003 10/07/2003
H
MH[GeV/c2]
Exclu
ded
SM
Rate is too low to be observed at the Tevatron
Rate is too low to be observed at the Tevatron
non-SM
• Models with suppressed fermion-Higgs coupling
• Some Universal ED models
7Gordon Watts (UW Seattle) WIN’2003 10/07/2003
H
Assume BR(H) = 1
Assume SM Higgs Production Cross-Section XhXpp
Photon ID, Apply Sliding Mass Window Cut
LimitLimitM
DataSM BG SumDYQCD
Luminosity = 51.8 pb-1(M) ~ 2.5 GeV/c2
Top Color HiggsEven
ts/8
GeV
DØ RunII Preliminary DØ RunII Preliminary
8Gordon Watts (UW Seattle) WIN’2003 10/07/2003
HExpectations
Higgs/SUSY WGRWith 50 pb-1 and BR=1 we expected a larger limit
Top Color Higgs
Working on bringing down the jet-photon misidentification rate
Working on bringing down the jet-photon misidentification rate
9Gordon Watts (UW Seattle) WIN’2003 10/07/2003
qqqqZ /Z /**HH++++HH----qqqqZ /Z /**HH++++HH----
H±± Production
• Higgs Triplet Model• LR Symmetric
versions• Attractive as
alternative to SUSY (CP, M)
• Sharply falling at the Tevatron
10Gordon Watts (UW Seattle) WIN’2003 10/07/2003
H±± Production
DØ look in the muon channel•e, (harder) possible
• Requires >=2 isolated • opening angle cuts (Z)• 2 of like sign
• Requires >=2 isolated • opening angle cuts (Z)• 2 of like sign
AnalysisCuts
(preselection)
= (0.47-0.50)±0.01 for MH = 80-200 GeV/c2 = (0.47-0.50)±0.01 for MH = 80-200 GeV/c2
11Gordon Watts (UW Seattle) WIN’2003 10/07/2003
H±± Results
• Luminosity = 107 pb-1
• M(H±±) > 95 GeV @ 95% c.l. (right-handed)• M(H±±) > 116 GeV @ 95% c.l. (left-handed)
– world’s 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
12Gordon Watts (UW Seattle) WIN’2003 10/07/2003
SUSY Large tan Search
Promising SUSY channel at the Higgs/SUSY WSPromising SUSY channel at the Higgs/SUSY WS
Since then
• Great deal of theory work• NLO cross sections almost
done• Generation parameters
better understood• bh channel better developed
~tan
CP-odd HiggsProduction
13Gordon Watts (UW Seattle) WIN’2003 10/07/2003
SUSY Large tan Search
Higgs WG DØ Expectations
• Jet ID• b-tagging
• b-tag 3
• dijet mass window cut• HF Jet Corrections
Coming soon to a conference near you …
Coming soon to a conference near you …
CompHEP + Pythia MCmh = 120 GeV/c2
14Gordon Watts (UW Seattle) WIN’2003 10/07/2003
If we didn’t show this…
Indirect Higgs Search…Indirect Higgs Search… LEPEWWG Sum’03
Mt < 2.5 GeV/c2
MW < 40 MeV/c2
Further Constrain the SM
Currently 59 MeV/c2 *
Currently 5.1 GeV/c2*
*these are combined, Run II predictions are per experiment
We have a long way to go…
15Gordon Watts (UW Seattle) WIN’2003 10/07/2003
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!
16Gordon Watts (UW Seattle) WIN’2003 10/07/2003
Conclusions• Initial results for , WW*, and H++H-- 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!
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