Gavin DaviesOn behalf of the CDF and DØ Collaborations

Recent Results from Recent Results from TevatronTevatron

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OutlineOutline•Introduction

– Tevatron

•Recent Results

•Prospects & Conclusions

[ Thanks to all my Tevatron colleagues ]

Legacy Hints & Excesses

Complementarity

Higgs

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Tevatron PerformanceTevatron Performance•Over 10.5fb-1 delivered per experiment

•Expect up to ~12 fb-1 by Oct 2011

Average data-taking efficiency ~90%

Results presented here use up to ~8fb-1

Many thanks to Accelerator Division

04/02 06/06 10/10

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A Wealth of Recent A Wealth of Recent ResultsResults

By way of example: http://www-d0.fnal.gov/Run2Physics/ResultsWinter2011.html

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A Wealth of Recent A Wealth of Recent ResultsResults

And….

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A Wealth of Recent A Wealth of Recent ResultsResults

And ‘finally’…

And likewise: http://www-cdf.fnal.gov/physics/physics.html

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‘‘Organising’ the Results..Organising’ the Results..

Legacy Hints & Excesses

Complementarity

top masstop properties W mass

t’top resonances

AFB(top)CP in heavy flavour decaystop spin correlationshigh xgluonW asymmetrySUSY searches

CP in Bs

HiggsSee talk on

thursday

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LegacyLegacy•Top mass

- Current Tevatron precision of 0.7%– CDF alone now at 0.6%

•W mass– Current Tevatron precision of 31MeV

mH<117GeV

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Other ‘Top’ ResultsOther ‘Top’ Results•eg Production Asymmetry AFB Raw AFB

Data: 0.0570.028 MC@NLO: 0.0170.004

022.0022.0

054.0138.0

l

l

pred

obs

A

A

dilepton

lepton+jet

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Other ‘Top’ & Electroweak Other ‘Top’ & Electroweak ResultsResults

•eg FCNC

•eg sinW

World’s best World’s best limitlimit

WorlWorld’s d’s

best best for for

light light quarquarks!ks!

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ComplementarityComplementarity•Proton-Antiproton: enables high precision CP measurements

due to symmetric initial stateeg D0 → K+K- & +-

)hhDΓ()hhΓ(D)hhDΓ()hhΓ(D

A 00

00

CP

ACP(D0 → π+π )= +0.220.24 0.11 %

IndirectCP

DirectCPCP a

τt

aA

World’s best World’s best resultsresults

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Alternatively…Alternatively…

ℓ+

ℓ-

ℓ-

ℓ+

Z/γ*

Z/γ*

σ(ditop+γ) =0.18±0.07 pb

σ(ZZ) =1.35±0.45(stat )±0.15(syst) pb

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Standard Model HiggsStandard Model Higgs

•Higgs mechanism– Additional scalar field in SM Lagrangian mass to W,Z & fermions

– Predicts neutral, spin 0 boson• But not its mass

•Direct searches at LEP2– mH > 114.4 GeV

•Precision data favour a light Higgs – mH < 185 GeV if LEP2 limit included

Accessible at Tevatron

(Not finding the Higgs boson will contradict SM & revolutionize particle physics… )

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Higgs at the TevatronHiggs at the Tevatron

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Strategy: Leave no stone Strategy: Leave no stone unturnedunturned

•All signal production and decay processes– eg W/Z+H and qqH at high mass– eg photons & taus, hadronic decays of W’s

•Optimise leading channels– eg b-tagging & mass resolution at low mass

•Constrain systematics with data

•Improved final discriminants– eg neural networks, boosted decision trees…

•Combine across all channels & experiments

95%

CL

limit

/ SM

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Low Mass: A ‘usual’ Low Mass: A ‘usual’ suspect suspect

•One of most powerful, but challenging channels

•Improved use of b-tagging information

– 15% gain in sensitivity

•Boosted decision trees– To reject multijet background– As final discriminant

• Split into 1 and 2 b-tag samples

Missing transverse energy

Two high pT jets, acoplanar, b-tagged

mH=115 GeV, 95% CL

Expected: 4.0×SM

Observed: 3.4×SM

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‘‘Low’ Mass: Additional Low’ Mass: Additional channelschannels

•H → ττ– 2nd largest BR at low mass– Tau pair + 1or 2 jets

•Hγγ– More data– Boosted decision tree

• ~30% gain in sensitivity

mH=115 GeV

Expected: 15×SM

Observed: 15×SM

mH=115 GeV:

Expected: 11×SMObserved: 20×SM

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High MassHigh Mass•New high mass combination for winter 2011

– All channels updated / improved– New channels CDF

D0

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H+X → lH+X → l++ll- - ++ missing Emissing ETT

•mH>135 GeV, H→W*W dominates •Clean - use gg → H production

– W/Z+H, qqH also contribute

•Subdivide– By jet multiplicity lepton quality

•Use MVA– With differing inputs

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Additional ChannelsAdditional Channels

Expected @ 160 4.3xSM

Expected @ 160 6.4xSM

W/Z H same sign dilepton Trileptons: WH

gg→H→WW→ gg→H→WW→lqq

Expected @ 160 7.8xSM Expected @ 160

5.1xSM

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CombinationCombination•Two statistical approaches

– Agree better than 5% over all masses

•Operate on binned final discriminants•Systematics (& correlations) included

– Rate and shape effects considered– Impact mitigated with constraints from data

•gg→H: NNLO +NNLL– arXiv:0811.3458, arXiv:0901.2427

•Use MSTW2008 NNLO PDFs– Error prescription from PDF4LHC

•Errors evaluated by jet bin•Further details on combinations:

http://tevnphwg.fnal.gov

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By ExperimentBy Experiment

•Exclusion by each experiment:

– CDF: excludes SM Higgs for 158 < mH < 168 GeV

– DØ: excludes SM Higgs for 163 < mH < 168 GeV

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Tevatron Tevatron

SM Higgs excluded at 95% CL for 158 < mH < 173 GeVExpected exclusion at 95% CL 153 < mH < 179 GeV

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TevatronTevatron

SM Higgs excluded at 99.5% CL for 162 < mH < 166 GeV

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Combining Direct & Indirect Combining Direct & Indirect LimitsLimits

Gfitter: combines direct and indirect constraints

At 95% CL:Allowed region <140GeV

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Higgs Beyond the SM…Higgs Beyond the SM…•Wide range of searches

– MSSM, NMSSM, Fermiophobic, 4 Generations

– Fermiophobic

World’s best limits

DØ preliminary, 8.2fb-1

124-202 GeV excluded

Mhf > 113 GeV

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SM Higgs ProspectsSM Higgs Prospects

Tevatron: Preliminary Higgs Projection

•Ongoing programme of improvements

•Expect exclusion over whole mass range

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•Tevatron and CDF/ DØ experiments continue to perform very well

•Wealth of new results– Across many areas

•High mass Higgs combination– Observed: 158 < mH < 173 GeV

– Expected: 153 < mH < 179 GeV

– Single experiment exclusion

•Many new results soon– eg BSM Higgs combination, full mass SM Higgs combination– eg Updated W mass, Muon CP asymmetry

Stay tuned: Tevatron at its best! Thank you

ConclusionsConclusions

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Backup slides

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CDF and DCDF and DØ ExperimentsØ Experiments• Both detectors extensively upgraded for Run IIa

– New silicon vertex detector– New tracking system– Upgraded muon chambers

• CDF: New plug calorimeter & ToF

•DØ– New solenoid & preshowers– Run IIb: New inner tracking layer

& L1 trigger

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DDØØ Data Taking Data Taking

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Other ‘Top’ ResultsOther ‘Top’ Results•eg t’

•eg spin-correlations

NLO QCD:

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FCNCFCNC

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CP Muon AsymmetryCP Muon Asymmetry

NN

NNA

nn

nna

See Guennadi Borissov’s talk on Thursday

BX

X

0B0B

N++, N−− : number of events with two like-sign dimuonsn+, n− : number of muons with given charge

bb

bbbsl NN

NNA

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Tevatron High Mass Tevatron High Mass CombinationCombination

Agreement between background model and data very good

With background subtraction

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CLCLss and CL and CLs+bs+b

Same exclusion ranges as Bayesian approach

CLs = CLs+b/CLb CLs+b