D? Results on New Phenomena (BSM) Searches

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D? Results on New Phenomena (BSM) Searches

• Subhendu Chakrabarti
• DAPNIA CEA Saclay
• On behalf of D? collaboration

Lake Louise Winter Institute 18 -24 Feb. 2007
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Outline
Various model dependent searches exist for New
Physics (Beyond Standard Model) at D?
Only overview of a subset of most recent
results are presented here , More results
in, http//www-d0.fnal.gov/Run2Physics/WWW/results
/np.html

• Extra dimensional Randall-Sundrum Graviton
• New Heavy Charged Boson W
• SUSY Trileptons
• Squarks and Gluinos
• GMSB SUSY in ??

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Search for Randall-Sundrum Graviton

• G? e e- / G? ??
• Search for two EM clusters,
• with PTgt25 GeV and ? lt1.1
• Data matches with SM Zee
• production and QCD background,
• No excess!
• Exclusion at 95 CL
• First RS excited resonance Graviton mass
• and dimensionless coupling constant

M1 lt865 GeV for kv8?/Mpl 0.1 M1 lt240 GeV for
kv8?/Mpl 0.01
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Search for New Heavy Charged Boson W
W ? e ?

• Event Selection

• Electrons with ETgt30 GeV and ?lt1.1
• Ratio of E Te/MET within (0.7-1.3)
• If Jet PTgt15 GeV in event, ??(j,MET/e)lt2.5
• METgt30 GeV
• MTgt150 GeV
• data matches with SM background prediction

• Mw gt965 GeV _at_ 95 CL

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Search for SUSY Trileptons
Associated Chargino/Neutralino
Production Cleanest channel in hadron colliders
for SUSY search

• Upgraded analysis eel

• Require two electrons PT gt8/12 GeV/c, third
  lepton PT gt4GeV/c
• ?F(e,e)lt2.9, Z mass veto (18-60) GeV
• METgt 22 GeV,MTgt 20 GeV,MET significancegt8,MET.
  PTl3 gt220 GeV2
• HT lt80 GeV (Anti top cut)

NO candidates found L1.1 fb-1 Expected
background 0.760.67

• Upgraded analysis likesign ??

• Require two likesign isolated muons PT gt13/8(lt35)
  GeV/c
• Invariant mass cut M??T (25-65), M??
  (12-110 ) GeV/c2
• MT (15-65) GeV/c2, METgt10 GeV , MET signficance
  gt 12 GeV, MET .PT ?2 gt160 GeV2/c

Observed one event L0.9 fb-1 Expected
background 1.1 0.4
NO EVIDENCE for SUSY
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Search for SUSY Trileptons
Associated Chargino/Neutralino Production

• Limits on ?.BR for five MSugra points ?
• Chargino mass region below
• 140 GeV/c2 ruled out (LEP 103 GeV/c2)

Combined results with e?l,??l,eel,like sign ??
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Search for Squarks and Gluinos in jets MET
Three different parameter region with tan ?3,
A00, ?lt0
Low m0 ? dijet (GeV) msquark 375 ltm gluino 416
m025, m1/2165
high m0 ? gluino (GeV) msquark 542 gtm gluino
296 m0500, m1/2100
Intermediate region 3jets msquark 380 mgluino
380 m0188, m1/2145

• Event Selection

• dijet search corresponds to scenario when squarks
  are much lighter than gluinos, so mostly squarks
  produced multijet is when gluino is much lighter
  than squarks

• Multijet with 4 jets
• pT gt35/20 GeV?lt2.5
• e/? veto
• ??(MET,j1/j2)gt900/500
• METgt100 GeV
• HT gt300 GeV

• Multijet with 3 jets
• pTgt35 GeV ?lt2.5
• e/? veto
• ??(MET,j1/j2)gt900/500
• METgt 150 GeV
• HT gt400 GeV

• Acoplanar dijet
• pTgt35 GeV ?lt2.5
• e/? veto
• ??(MET,j1/j2)gt900/500
• METgt225 GeV
• HT gt300 GeV

Good agreement with SM prediction
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Search for Squarks and Gluinos in jets MET
gluino
intermediate
dijet
D0
LEP
No MSUGRA
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GMSB Inspired SUSY Models in ??

• Search for Gauge mediated SUSY breaking with NLSP

Messenger mass Mm2? No of messengers N51 tan ?
15 ?gt0
Require 2 photons ET(?)gt25 GeV METgt45 GeV No
back-to-back jet with MET ?F(MET,jet)lt2.5
Remaining 4 candidate events in data Total
expected background 2.1 0.7
Lower limit on lightest Neutralino Mass gt120
GeV Chargino Mass gt 220 GeV
Good agreement
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Conclusions

• No evidence of New Phenomena with 1 fb-1 data yet
  !
• Several New Phenomena Search reaching sensitivity
  in the parameter space well beyond existing
  limits
• More data on tape
• Stay tuned.