Download - New Physics Searches at the Tevatron
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New Physics New Physics SearchesSearches at the at the TevatronTevatronAmitabh Lath
Rutgers University/CDFFor the CDF and D0 Collaborations
ICHEP 2004Beijing
CDF D0
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Tevatron:Tevatron: The Energy Frontier The Energy Frontier
1.96 TeV CM Energy
500 pb-1 to tape NOW 4 fb-1 to tape
by FY 2009.
(8 fb-1 possible?)
• When will new physics show up?• What will it look like? • Will our triggers and analyses be sensitive to it?
We need to think beyond established theories
Main Injector & Recycler
Tevatron
Chicago!
p source
Booster
p
p
p p 1.96 TeV
CDFDØ
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New Physics:New Physics: Beyond Higgs, SUSYBeyond Higgs, SUSY
Use familiar objects: e, , jet, ET Massive Objects:
Z’/W’, Gravitons (leptons, photons)
Leptoquarks (leptons, ET , jets)
Extra dimensions (leptons, jets, ET)
Compositeness: Excited Fermions (leptons, photons)
Technicolor (leptons)
Truly Exotic Objects Charged Massive Particles (CHAMPS) Magnetic Monopoles
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The Classic SearchesThe Classic Searchese+e-: Probe Z’, RS Graviton…
Hypothetical Z’
Note: agreement over 2 orders of magnitude in mee.
Large Extra dimensions
D0 Run II 200 pb-1
D0
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The Classic SearchesThe Classic Searches continuedcontinued : Probe Z’, RS Graviton…
euses EM calorimeter, resolution better at harder e.uses tracker, resolution better at softer .
e, complimentary:
100 pb-1D0
D0 250 pb-1
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Typical High Mass events. Typical High Mass events. CLEAN!CLEAN!
CDFD0
Historically ee, ( searches have paid off handsomely at hadron machines.
Insensitive to QCD remnants.
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Dilepton Cross-Section Limits: ee Dilepton Cross-Section Limits: ee
D0:Z’ee Limit 780 GeV/c2
CDF :Z’ee Limit 750 GeV/c2
D0 200 pb-1
LIMIT
S
~50 fb
D0
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Dilepton Cross-Section Limits:Dilepton Cross-Section Limits:
CDF :Z’ Little Higgs(cot=0.7) 720 GeV/c2
D0 250 pb-1
D0 :Z’SM) > 680 GeV/c2LIM
ITS
~60 fb
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Technicolor:Technicolor:
Almost there! Need another order of magnitude
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Another promising channelAnother promising channel: : DiphotonDiphoton
an e without a track.
LIMITS
~70 fb
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Combined LimitsCombined Limits: : Graviton, LEDGraviton, LED
•Pairs of hard, isolated leptons and photons are powerful tools to hunt new physics.
•The SM backgroundsare small and well understood.
•The results are *BR, which can be interpreted in a variety of ways by different models (some of which haven’t been published yet!)
= F/Ms4
D0 Extra dimensions
limit:0.24 TeV-1
MPL>1.43 TeV (GRW) World’s best limit on MPL
D0
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Adding Adding EETT : : W’ SearchW’ Search
Electron + ET
Neutrinos show up as MET
Many sources of ET tails: Muons Cracks in detector Energy calib.
Plot shows we have good understanding of ET.
W’ limit plot work in progress.
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e+e+: Compositeness : Compositeness (Excited electrons)(Excited electrons)
contact
Gauge mediated
Electron +
3 events seen
me
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Limits on excited electronsLimits on excited electrons
GaugeLIM
ITS
~70 fb
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Electrons+JetsElectrons+Jets: Leptoquarks: Leptoquarks
Two energetic electrons.Two jets
1st gen. LQ
Scalar Energy sum, eejj
D0
D0
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=1
Electrons+JetsElectrons+Jets: Leptoquarks: Leptoquarks
•Limit ~ 100 fb•More challenging at lower mass.
• QCD bg requires hard cuts that affect limit at low mass.
• Jets harder to study than e, • Jet multiplicity hard to simulate.• Jet quark, g correspondence hard to disentangle• Jet energy resolution not nearly that of e, .
Two energetic electrons.Two jets
238 GeV/c2
D0
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Electron+Jets+EElectron+Jets+ETT: Leptoquarks: Leptoquarks
•One energetic electron.• ET
• Two jets is BR(LQeq) =0.5
197 GeV/c2
Limit
~ 100 fb
D0
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Jets + EJets + ETT: : Leptoquark Leptoquark
No electrons in final stateLeptoquark goes to , jet.
Challenging at low mass.
Important for squark/gluino searches
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Leptoquarks (1Leptoquarks (1stst Gen. Limits) Gen. Limits)
D0 200 pb-1D0
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Now with Now with :: LQ 2 LQ 2ndnd Generation Generation
Two muons,Two jets.
Limit
~ 70 fb
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Jets+METJets+MET:Large Extra Dimensions:Large Extra Dimensions
No k factor
Most stringent
Number of Dimensions
Need to understand calorimetry, tracking, acceptance in excruciating detail.
QC
D
D0
D0
D0
D0
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A special sort of jetA special sort of jet: : hadronshadrons
See Weiming Yao’s talk for more on tausLIM
ITS
~1000 fb
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Truly Exotic:Truly Exotic: CHAMPS CHAMPS CHAMPS are slow moving
Large Ionization loss Long time of flight
Highly penetrating Will look like a muon
misolated-stop > 108 GeV/c2
LIMITS
~10,000 fb
CH
AM
P
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Truly Exotic: Truly Exotic: MonopoleMonopole •Bends in the wrong plane ( high pt)•Large ionization in scint (>500 Mips!)•Large dE/dx in drift chamber
mmonopole > 350 GeV/c2
LIMIT
S
~300 fb
TOF trig
ger d
esig
ned
spec
ifica
lly fo
r
monopole
sear
ch
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SummarySummary Tevatron luminosity is ramping up.
4 fb-1 promised by 2009. Exciting physics possible. Translating detector understanding to physics.
Objects like e, , ET, jets, (b) are now reconstructed w/ excellent efficiency, purity. We use these to search for V’, Technicolor, LQ, excited fermions, extra dim...
Going to get even better: More luminosity, better understanding. Now, limits ~50 - 100 fb (leptons, photons). Soon, ~10 fb!
We think outside the box. Hunt for new objects like CHAMPS, monopoles… Could use help from theorists here.
We hope to see new physics soon. We are sick and tired of making exclusion plots!
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Backup slides
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TevatronTevatron Promises High Luminosity…Promises High Luminosity…
Aug04: ~0.7fb-1 delivered: > design
12 pb-1 / week currently: above “design”
Start of Fiscal YearOct 03
4 fb-1 line : 2009? Earlier?
Slam dunk!
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But can they deliver?But can they deliver?
Run 1
Last 30 weeks
Recent news is encouraging!