Recent Results from Tevatron
Tomonobu Tomura(University of Tsukuba)
for CDF and DØ Collaborations
2009/03/05

KEKPH091

Tevatron Run IIChicago

CDF
TEVATRON

D0

MAIN INJECTORThe world's highest-energy particle collider, so far.
Proton-antiproton collisions at s = 1.96 TeV
Tevatron is performing really well: delivered 6 fb-1


7~8 fb-1 expected by the end of 2009. (8~9 fb-1 if run in FY10)

2009/03/05

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Tevatron Status
Continually establishing new records!
Peak luminosity~3.5×1032 cm-2 s-1

Weekly integrated luminosity
78 pb-1

Annual integrated luminosity
1.8 fb-1 (US FY2008)

Avarage pbar accumulation rate

21×1010 pbar/ hour

Very stable operation
Maximizing integrated luminosity
10 weeks shutdown in 2009 summer

2009/03/05

KEKPH093

Tevatron Prospects
Integrated luminosity (fb-1)

Updated Feb 20099.32 fb-1
FY10 start

7.78 fb-1

Actual Performancefor FY02-FY08

Highest Int. Lum
Lowest Int. Lum



FY2010FY09 start

2009/03/05

time since FY04

KEKPH09

FNAL plans torun (if budgetallows) andCDF/DØ areready.
Another ~2 fb-1,total ~9 fb-1
4

CDF/DØ Detectors

CDF:
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8 layer silicon vertex detector
8 super layer drift chamber
1.4T solenoid
Good particle identification (K, π)
Central/Wall/Plug calorimeters
Scintillator+drift chamber muon
detectors

2009/03/05

DØ:



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8 layer silicon vertex detector
16 layers scintillating fibers
2T solenoid
Central/Endcap calorimenters
1.8T toroid
3 layer muon scintillator +drift tubes (Extended muoncoverage)

5Electroweak Physics

2009/03/05

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W Boson Mass

2009/03/05

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W Mass Measurement (CDF)∫ L dt ≈ 200 pb-1

events / 0.5 GeV

CDF II preliminary

World average:
MW = 80.398 ± 0.025 GeV/c2

1500

1000

CDF (∫L=200 pb-1):
MW = 80.413 ± 0.034 (stat)± 0.034 (syst) GeV/c2
ΔMW = 0.048 GeV/c2

MW = (80493 ± 48stat) MeV500

χ2/dof = 86 / 48060

7080

100mT (eν) (GeV)∫ L dt ≈ 200 pb-1

CDF II preliminary
events / 0.5 GeV

901000500

Single most precise
measurement!

MW = (80349 ± 54stat) MeV
χ2/dof = 59 / 48

0607080

2009/03/05[Phys. Rev. Lett.
99, 151801 (2007),
Phys. Rev. D
77, 112001 (2008)]

90100mT (μν) (GeV)

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W Mass Projections

ΔMW < 25 MeV
w/ ~2 fb-1

2009/03/05

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Top Quark Physics

2009/03/05

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Top Pair Production

Dominant process
10%~20%2009/03/05

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Top Pair Signature

Dilepton

Lepton+Jet

All Hadronic• 2 lepton• 2 b-jet• MET• 1 lepton• 4 jet (2 b-jet)• MET• 6 jet (2 b-jet)Γ−1 ≈ (1.5 GeV) << Λ-1QCD ~ (200 MeV)
−1-1Top quark decays as a naked quarkÎ Information on spin polarization andmomentum is directly transferred todecay products
2009/03/05

KEKPH09

Categorize ttbar
events into 3 decay
types according to W
decay mode

12

Top Pair Production
Cross Section

2009/03/05

Now better than theoreticaluncertainties
Luminosity is dominant source ofuncertainty
KEKPH0913

Ratio of Top Pair to Z Boson
Cross Section (CDF)⎧σ = 6.97 + 0.42 (stat) + 0.40 (syst) ± 0.40(lumi) pb⎪ tt− 0.41− 0.42⎨+ 4.4+ 16.63⎪⎩σ Z = 253.27 ± 1.01(stat) − 4.6 (syst) − 13.71 (lumi) pb⎧σ tt = 7.1 ± 0.4(stat) ± 0.6(syst) ± 0.4(lumi) pb⎨σ = 253.5 ± 1.1(stat) ± 4.5(syst) ± 14.9(lumi) pb⎩ Z41 (syst) ± 0.14(theo)σ tt = 6.89 ± 0.41(stat) −+ 00..37

σ tt = 7.0 ± 0.4(stat) ± 0.6(syst) ± 0.1(theo)Taking the ratio of the top pair to the Z cross sections,the total uncertainty is decreased by ~10%.
2009/03/05

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Top Quark Mass15

Mass of the Top Quark (*Preliminary)
CDF-I di-l167.4 ±10.3 ± 4.9

D0-I di-l168.4 ±12.3 ± 3.6*

CDF-II di-l171.2 ± 2.7 ± 2.9*

D0-II di-l174.4 ± 3.2 ± 2.1

CDF-I l+j176.1 ± 5.1 ± 5.3

D0-I l+j

180.1 ± 3.9 ± 3.6*

CDF-II l+j

172.2 ± 1.0 ± 1.3*

D0-IIa l+j

171.5 ± 1.5 ± 1.5*

D0-IIb l+j

173.0 ± 1.3 ± 1.7

CDF-I all-j

186.0 ±10.0 ± 5.7*

CDF-II all-j

176.9 ± 2.6 ± 3.3*

CDF-II trk

175.3 ± 6.2 ± 3.0*

Tevatron July’08

172.4 ± 0.7 ± 1.0

CDF March’07

χ2/dof±=1.5
6.9/11.0(81%)
12.4
± 2.2

Goal before Run-II started :3 GeV/c2 with 2 fb-1(stat.) ± (syst.)

0
150

160

2009/03/05

170
180
2
mtop (GeV/c )

190

200

Now better than 1%
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Top Mass Measurement (CDF)Template Method (Lepton+jets / Dilepton)
Lepton+jets
Event-by-event
mtopreco from χ2fitter Utilize m for in situ
jj
JES calibration
Dilepton

Neutrino Weighting
Algorithm

mT 2(mT = mbλ + mν + 2 ETbλETν − pTbλ ⋅ pνT222[ {}])

mT 2 ≡ min max mT(1), mT(2)2009/03/05

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Top Mass Measurement (CDF)Template Method (Lepton+jets / Dilepton)
3.0 fb-1

M top = 171.8 ± 1.5 (stat + JES) ± 1.1 (syst) GeV c2
2009/03/05

KEKPH0917

ttbar Differential Cross Section,
dσ/dMttbar (CDF)
Singular Value
Decomposition(SVD) of theresponse matrix

2.7 fb-1No evidence ofinconsistency
with SM

Randall-Sundrum
Model Graviton

2009/03/05

κ/MPl > 0.16 at the 95% CL

KEKPH0918

Single Top Production

S-channel
Cross section ∝ |Vtb|2

t-channel

No need to assume unitarity of CKM matrix nor threegenerations of quarks
 On the assumption of CKM unitarity: Vtb = 0.99
 3 generations: Can be derived from Br(t→Wb)

Important to understand bkg of WH event for low mass
Higgs (mH < 130 GeV)Benchmark of Higgs search in WH
 σ(WH) : σ(Single Top) ~ 1 : 102009/03/05

KEKPH0919

Single Top Cross Section(CDF)

4.2σ
Vtb = 0.97 ± 0.13 (exp) ± 0.07 (theo)

Vtb > 0.71 @95% C.L.
2009/03/05

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Single Top Cross Section (DØ)

3.6σ

0.00
Vtb = 1.00 +− 0.12

Vtb > 0.68 @95% C.L.
2009/03/05

KEKPH0921

New Channel for Single Top(CDF)
MET + jets (2.1 fb-1)


Leptonic decays with hadronic τ and e/μ not fiducial
Performing orthogonal channel gives extra information
Contribute to the combination of single top cross section

2.5 pbσ = 4 .9 +− 2.2
Significance: 2.1σ
(Expected: 1.4σ)

2009/03/05

KEKPH0922

Single Top Prospects
Expected uncertainty onVtb as a function of ∫Ldt
 Uncertainties arise from:

Experiment Cross-section
dependence on Mtop
 Factorization andrenormalization scales Parton distributionfunctions αs

2009/03/05

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Anomalous Top Couplings(DØ)
W Helicity+
Single Top

2009/03/05

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Higgs Search

2009/03/05

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Indirect Limits on Higgs

2009/03/05

KEKPH09

26

Higgs Cross Section andBranching Ratio

2009/03/05KEKPH0927

WH → lνbb (CDF & DØ)
DØ:

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Updated on Feb 5, 2009
Limit/SM < 6.7 @115GeV/c2

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CDF:

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Updated on Nov 7, 2008
Combined result of NN andME+BDT
Improved by 15%
Limit/SM < 4.8 @115 GeV/c2

KEKPH0928



2009/03/05

ZH → llbb (CDF)
Looser b-jet identification
 2D Neural Net
 Improve dijet mass resolution
with MET projection technique

2009/03/05

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WH → WWW* (CDF)2 like-sign leptons using Boosted
Decision Tree discriminant

2009/03/05

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Combined Limits on Higgs(CDF & DØ)

ZH→llbb
WH→lνbbDØ:

Updated on Aug 2, 2008
New WH→lνbb result NOT
included



CDF:


Updated on Jan 16, 2009
Updates since last summer

2009/03/05

WH→WWW

KEKPH09

WH→lνbb
WH→WWW
ZH→llbb

31

Higgs Exclusion (CDF & DØ)
CDF+DØ combination
Updated on Jul 30, 2008

One mass point, 170 GeV, excluded @ 95% C.L.
 15 GeV window [162 : 177] excluded @ 90% C.L.
2009/03/05

KEKPH0932

Projections of Higgs Search

CDF+DØ projections assuming they perform the same
 Possible improvements:

Acceptance, Analysis method, jet/MET resolutions, etc.

Good possibility to see 3σ evidence to a Higgs of 160GeV/c2
2009/03/05

KEKPH0933

Summary

Tevatron is operating well. Better than ever!


CDF and DØ experiments are ready to run for FY2010. ∫Ldt ~ 9 fb-1 isexpected.

Top quark properties are being measured more and more precisely.
Mass precision is now less than 1%.
Top quark properties are consistent with SM so far.

We are sensitive to Higgs of 160 GeV/c2.

Stay tuned for interesting results from Tevatron with more than
~3 fb-1 data in 2009!


New top mass combination
Single top search
Updated Higgs limit
New results in EW, B, Exotic, QCD, …

2009/03/05

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