tevatron cdf top quark massrencontres de moriond ew, la thuile, march 19, 2014 ... top quark mass...

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Rencontres de Moriond EW, La Thuile, March 19, 2014

CDFTEVATRON

Top Quark Mass

L. BrigliadoriUniversity of Bologna

On behalf of the CDF and DØ Collaborations

OUTLINE• The Top Quark

• Measurement Strategies.

• Recent Results.

• Mtop World Average

• Summary and Conclusions.

Luca BrigliadoriUniversity of Bologna

Rencontres de Moriond EWMarch 19, 2014

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CDF The Top Quark

• Observed in 1995 at Fermilab....... not a big surprise (...if we trust the SM...)

• ... but Mtop striking large!

• Why (keep on) to measureMtop ?

– Inside the SM:

∗ Test SM predictions

∗ Test SM consistency

– Beyond the SM:∗ Constraints on New Physics

∗ Hints on EWSB?

(GeV)topm

(G

eV)

Wm

< 127 GeV

H

115 < m

< 1000 GeV

H

600 < m

155 160 165 170 175 180 185 190 195

80.3

80.35

80.4

80.45

80.5

top (2009), m

W68% CL (by area) m

top (2012), m

W68% CL (by area) m

& direct Higgs exclusion)top

, mW

LEPEWWG (2011) 68% CL (excluding m

March 2012

[GeV]tm

160 165 170 175 180 185 1902 χ

∆0

1

2

3

4

5

6

7

8

9

10

σ1

σ2

σ3 measurementt

SM fit w/o m

measurementsH

and Mt

SM fit w/o m

ATLAS measurement [arXiv:1203:5755]tkinm

CMS measurement [arXiv:1209:2319]tkinm

Tevatron average [arXiv:1305.3929]tkinm

[arXiv:1207.0980]tt

σ obtained from Tevatron tpole

m

G fitter SM

Sep 13



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CDF Top Quark Signatures

At the Tevatron mainly tt̄ production via strong interaction

∼ 85%

+ +

∼ 15%

In the SM : BR(t → Wb) ≃ 100% ⇒ tt̄ final states defined byW s’ decays

2 high pT charged leptons,2 b-jets, /ET

4 q-jets,2 b-jets

1 high pT charged lepton,2 q-jets, 2b-jets, /ET



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CDF Top Mass Challenges

• σtt̄ / σinel ≃ 10−10 !!!

• ... Event Selection :

– Triggers– b-tagging algorithms.– High ET and central (|η| ≤ 2) Jets.– Lepton Id (Dilepton, Lepton + jets).

• Reconstruction :

– Measure “Jets” and not partons

Need corrections to obtain parton energy

⇒ JetEnergyScale. σJES/JES ≈ 2% to 6%

⇒ Important contribution toσMtop(syst)

– Jets-to-partons assignments

Which jet comes from which particle?Combinatoric problem!

– Undetectedν ’s (Dilepton, Lepton + jets).

Need assumptions. Multiple solutions.



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CDF Measurement Strategies

• Matrix Element (ME)

– Define the probability, Pev , that the observed kinematics,~y, arise from possible signal or bkgkinematics~x at parton level :

∗ dσ(~x) LO differential x-section of a final state~x at parton level.Depending onMtop for tt̄ events, but not for bkg.

∗ W(~y, ~x) “Transfer function”, i.e. probability to measure the observedset of variables~y, given~x at parton level. Depends onJES.

∗ ftt̄ Fraction of signal events expected in the data.

– Maximize Lsample∝∏

events

Pev(~y, ftt̄, Mtop) evaluated for observed data

• Template Method

– Consider a set of observables,~x, sensitive toMtop.Evaluate and plot the set for each event⇒ “Templates”

– Maximize a likelihood whereobserved distributionsare compared to expectations for differentMtop andsignal fractions,ftt̄.

Lsample ∝∏

events

∏

~x

Lshape(xi|ftt̄, Mtop)

]2 [GeV/crectm

100 150 200 250 300

)2F

ract

ion

of E

vent

s/(2

.5 G

eV/c

0

0.02

0.04

0.06

0.08

0.1

2 = 167.5 GeV/ctop M



JES)∆,top

| Mrect

(msP

templatesrect mtt

JES = 0.0)∆ 2 tags events (≥

)-1 - Preliminary (9.3 fbtopCDF Run II - All Hadronic M



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CDF Measurement Channels

Lepton + Jets

Reasonable Bkg,Good Statistics....

The Golden Channel!

• Jets-to-Partons assignment ambiguity

• Well reconstructed kinematics (butpνz

ambiguity)

Dilepton

The cleanest sample...The smallest statistics

• Small combinatoric problem

• Underconstrained kinematics (2 undetectedν’s)

All-Jets

Huge QCD Bkg...Large Statistics

Challenging!

• Need “fine tuned” selections to obtain goodS/B

• Large Jets-to-Partons assignment ambiguity

• Fully reconstructed kinematics

MissingET + Jets

• Selection defined to be complementaryto other channels.

• Mostly L + Jets with undetected lepton



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CDF Dilepton

• DØ , Matrix Element, 5.4 fb−1

• Phys. Rev. Lett. 107, 082004 (2011).

• ee, eµ, µµ channels

Mtop = 174.0 ± 1.8 (stat) ± 2.4 (syst)GeV

(GeV)tm160 170 180 190

max

tot

/Lto

tL

0

0.5

1

-1D0 5.4fb

• DØ , Template by NWA, 4.3 + 1.0 fb−1

• Phys. Rev D86, 051103(R) (2012)

• Neutrino Weighting Algorithm : templates based on an event weightfor possible solutions of underconstrained kinematics.

• ee, eµ, µµ channels, selection similar to ME analysis.

• JES calibration from Lepton + Jets analysis is used.

• Combined with NWA + Matrix Weighting @ 1 fb−1


(GeV)

wµ120140160180200 (GeV)

tm

160170

180190

200

Pro

babi

lity

dens

ity

00.10.20.30.40.50.6

-310×

WTνDØ,

=30 GeVwσ

d)

• Combination :Mtop = 173.9±1.9 (stat)±1.4 (syst)GeV

σMtop/Mtop ≃ 1.4%



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CDF Dilepton

• CDF , Templates, 9.1 fb−1

• NewPreliminary result with full CDF dataset(January 2014, CDF conference note 11072)

• “Hybrid” variable method to reduce JES uncertainty :

– Templates byMefft = w · Mreco

t + (1 − w) · Maltt

– Mrecot sensitive to trueMtop. Defined by NWA.

– Maltt less sensitive toMtop, but not based on jet energies.

– w = 0.7 :defined to minimize expected (stat + JES) uncertainty

• Two independent samples :0-tag, ≥ 1-tag



0-tag fitted templates

≥ 1-tag fitted templates



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CDF Lepton + Jets

• DØ, Matrix Element, 2.6 + 1.0 fb−1

• Phys. Rev. D84 (2011) 032004.

• Events with 1 highpT e /µ, ≡ 4 Jets, large/ET , ≥ 1 b-tag

• For each event evaluate ME-based probability as aweighted sum over possible parton-jet combinations

• Dependence onJES given by Transfer FunctionsW(~y, ~x)

• SimultaneousJES calibration by jets assigned toW boson.

(GeV)xE0 50 100 150

)-1

=1)

(GeV

JES

,k y,E x

(Eje

tW 0

0.02

0.04

0.06

(GeV)yE 30 60 90 120

| < 1η0.5 < |(b) DØ

JetE Transfer Functions

GeVtm170 172 174 176 178 180 182

JES

k

0.98

0.99

1

1.01

1.02

1.03

1.04

1.05

1.06-1DØ, 2.6 fb

1sd

2sd

3sd


Combined with 1 fb−1⇒ Best DØ measurement





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CDF Lepton + Jets

• CDF, Templates, 8.7 fb−1

• Phys. Rev. Lett. 109 (2012) 152003.

• 3D templates :mrecot vs m

reco(2)t vs mjj

• mjj used for in situ JES calibration



Best single measurement from Tevatron

)2 (GeV/crecotm

120 140 160 180 200 220 240

)2 (

GeV

/cjj

m

50

60

70

80

90

100

110

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

)2 = 172.0 GeV/ctop

lepton + jets, 1-tag Signal probability (M ) 2 = 172.0 GeV/ctop

lepton + jets, 1-tag Signal probability (M

mjj vsmrecot

)2

(GeV/cjjm50 60 70 80 90 100 110 120

Arb

uni

ts

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

2-tag)cσ (JES∆-1.0

)cσ (JES∆0.0

)cσ (JES∆+1.0

2-tag

mjj dependence onJES

)2

(GeV/crecotm

100 150 200 250 300 350

)2E

vent

s/(5

GeV

/c

0

50

100

150

200

250

300

350

400CDF II Preliminary

)-1Data (8.7 fbSignal+BkgdBkgd onlyAll

)2 (GeV/cm50 60 70 80 90 100 110 120

)2E

vent

s/(1

.5 G

eV/c

0

50

100

150

200

250

300

350CDF II Preliminary

)-1Data (8.7 fbSignal+BkgdBkgd onlyAll



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CDF All-Hadronic


• NewPreliminary result with full CDF dataset(February 2014, CDF conference note 11084)

• Tuned event selection based on Neural Net,b-tag

• Data driven bkg modeling

• S/B about1/1 for ≥ 2-tag events.

• In each event reconstruct (χ2 minimization) :— a “top mass”, mrec

t

— a “W mass”, mrecW

⇒ JES calibration

]2 [GeV/crectm

100 150 200 250 300

)2F

ract

ion

of E

vent

s/(2

.5 G

eV/c

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08




JES)∆,top

| Mrect

(msP

templatesrect mtt

JES = 0.0)∆1 tag events (


]2 [GeV/crecWm

20 40 60 80 100 120 140 160 180 200 220

)2F

ract

ion

of E

vent

s/(2

.5 G

eV/c

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

JES = -2.0∆

JES = 0.0∆

JES = 2.0∆

JES)∆,top

| MrecW

(msP

templatesrecW mtt

)2 = 172.5 GeV/ctop

1 tag events (M


]2 [GeV/crectm

100 150 200 250 300

)2E

vent

s/(5

.0 G

eV/c

0

100

200

300

400

500 1-tag events≥

)-1 Data (9.3 fb

t Fitted Bkg + t

Fitted Bkg


Mtop = 175.07±1.19 (stat)±1.56 (syst)GeV




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CDF MissingET + Jets


• Phys. Rev D88 (2013) 011101

• Require large/ET , no tight lepton

⇒ independent of All-Had, L+jets, Dilepton

• Exploiting NN selection and bkg modelingsimilar to All-Had analysis

• /ET treated as due toW → ℓν with “lost” charged leptonin event reconstruction

• Same technique used in CDF L+jets :

– 3D templates usingmrecot , mreco(2)

t , mjj

– mjj used for in situ JES calibration



NN output 0 0.5 1

Eve

nts

0

50

100

150

200

Data

)2 = 172.5 GeV/ct

Signal (M

Background

)-1CDF Run II Preliminary (8.7 fb

2tag MET+Jets Events

Neural Net Output

)2 (GeV/ctopM170 172 174 176 178

)2 (GeV/ctopM170 172 174 176 178

) cσ (JE

S∆

-0.6

-0.4

-0.2

0

0.2

0.4

0.6 log(L) = 0.5∆

log(L) = 2.0∆

log(L) = 4.5∆

-1CDF II Preliminary 8.7 fb



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CDF Mtop Systematic Uncertainties

⇐ example from CDF Dileptons

• Precision on the Top Mass measurementsnow limited by systematic uncertaintiesin all channels.

• JES uncertainty greatly reduced especially byin situ calibration techniques⇒ partially statistical

• CDF and DØ Collaborations performed a jointeffort in the past years in order :∗ to define a common way to evaluate

systematics

∗ to avoid possible “double counting” of someeffect

∗ to evaluate correlations among differentmeasurements

∗ to study possible neglectedsources of uncertainties



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CDF Tevatron Top Mass

CDF + DØ, March 2013 (arXiv:1305.3939)

Mtop = 173.20±0.51(stat)±0.71(syst)GeV

Individual channels

Dilepton Mtop = 170.0 ± 2.1GeV

Lepton + Jets Mtop = 173.2 ± 0.9GeV

All-Hadronic Mtop = 172.7 ± 1.9GeV

/ET + Jets Mtop = 173.8 ± 1.8GeV

• Best results of each experiment in each channelfrom Run I and Run II combined.

• Recent updates from CDFnot included yet

• All correlations taken into account.

• Good agreement among resultsfrom individual channels

• Mtop known at 0.50% (March ’13).

• Precision now limited by systematic uncertaintiesin all channels.



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CDF Mtop WORLD AVERAGE

The ATLAS, CDF, CMS and DØ Collaborations just approved thevery first Tevatron + LHC Mtop combination

Mtop = 173.34 ± 0.76GeV

[GeV]topm165 170 175 180 185

1

17

LHC Sept. 2013 0.88)± 0.26 ± (0.23 0.95±173.29

Tevatron March 2013 (Run I+II) 0.61)± 0.36 ± (0.51 0.87±173.20 prob.=93%2χ / ndf =4.3/102χ World comb. 2014 0.67)± 0.24 ± (0.27 0.76±173.34

-1 = 3.5 fbint L

CMS 2011, all jets 1.23)± (0.69 1.41±173.49

-1 = 4.9 fbint L

CMS 2011, di-lepton 1.46)± (0.43 1.52±172.50

-1 = 4.9 fbint L

CMS 2011, l+jets 0.97)± 0.33 ± (0.27 1.06±173.49

-1 = 4.7 fbint L

ATLAS 2011, di-lepton 1.50)± (0.64 1.63±173.09

-1 = 4.7 fbint L

ATLAS 2011, l+jets 1.35)± 0.72 ± (0.23 1.55±172.31

-1 = 5.3 fbint L

D0 RunII, di-lepton 1.38)± 0.55 ± (2.36 2.79±174.00

-1 = 3.6 fbint L

D0 RunII, l+jets 1.16)± 0.47 ± (0.83 1.50±174.94

-1 = 8.7 fbint L

+jetsmiss

TCDF RunII, E

0.86)± 1.05 ± (1.26 1.85±173.93 -1 = 5.8 fbint L

CDF RunII, all jets 1.04)± 0.95 ± (1.43 2.01±172.47

-1 = 5.6 fbint L

CDF RunII, di-lepton 3.13)± (1.95 3.69±170.28

-1 = 8.7 fbint L

CDF RunII, l+jets 0.86)± 0.49 ± (0.52 1.12±172.85

-1 - 8.7 fb-1 = 3.5 fbint

combination - March 2014, LtopTevatron+LHC mATLAS + CDF + CMS + D0 Preliminary

) syst. iJES stat.total (Pre

viou

sC

omb.

∗ arXiv 1403.4427 [hep-ex]

∗ Tevatron : Run II data(up to 8.7 fb1)

∗ LHC : 2011 data(up to 4.9 fb1)

∗ Best single measurementin each channelfrom each experiment

∗13% improvement w.r.t.most precise singleCollider combination

∗28% improvement w.r.t.most precise single input



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ρEXP ρLHC ρTEVρCOL

ρCDF ρD0 ρATL ρCMS ρATL−TEV ρCMS−TEV

Stat 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

iJES 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0

stdJES 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0

flavourJES 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0

bJES 1.0 1.0 1.0 1.0 0.5 1.0 1.0 0.5

MC 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

Rad 1.0 1.0 1.0 1.0 1.0 1.0 0.5 0.5

CR 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

PDF 1.0 1.0 1.0 1.0 1.0 1.0 0.5 0.5

DetMod 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0

b-tag 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0

LepPt 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0

BGMC† 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0

BGData 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Meth 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

MHI 1.0 1.0 1.0 1.0 1.0 0.0 0.0 0.0

Multiplicative factor f [%]

0 20 40 60 80 100

[MeV

]to

p m∆

-250

-200

-150

-100

-50

0

50

100

150

200

EXPρ ×f

TEVρ ×f

LHCρ ×f

COLρ ×f

ALLρ ×f

ATLAS + CDF + CMS + D0 Preliminary

Multiplicative factor f [%]

0 20 40 60 80 100)

[MeV

]to

p(mσ ∆

-350

-300

-250

-200

-150

-100

-50

0

50

100

EXPρ ×f

TEVρ ×f

LHCρ ×f

COLρ ×f

ALLρ ×f


• First combination between the two Colliders

• Big effort performed in order to :

∗ classify uncertainties

∗ define correlations

• Various correlation scenarios have been checked



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• Combine channels / experiments / colliders simultaneoslybut separately(i.e. correlated but different mtop fit parameters)

[GeV]topm170 172 174 176 178 180

1

16

LHC Sept. 2013 0.88)± 0.26 ± (0.23 0.95±173.29

Tevatron March 2013 (Run I+II) 0.61)± 0.36 ± (0.51 0.87±173.20

World comb. 2014 0.67)± 0.24 ± (0.27 0.76±173.34

LHC 0.87)± 0.26 ± (0.23 0.94±173.26

Tevatron 0.69)± 0.36 ± (0.46 0.91±173.41

CMS 0.94)± 0.29 ± (0.30 1.02±173.54

ATLAS 1.34)± 0.41 ± (0.31 1.43±172.70

D0 1.13)± 0.49 ± (0.79 1.46±174.62

CDF 0.68)± 0.45 ± (0.53 0.98±172.96

+jetsmissTE 0.71)± 1.05 ± (1.28 1.80±174.03

all jets 0.89)± 0.25 ± (0.65 1.13±173.35

di-lepton 0.98)± 0.19 ± (0.44 1.09±172.73

l+jets 0.68)± 0.26 ± (0.27 0.78±173.23

-1 - 8.7 fb-1 = 3.5 fbint

corr. obs. - March 2014, LtopTevatron+LHC m


) syst. iJES stat.total (

Cor

rela

ted

Obs

erva

bles

Pre

viou

sC

omb.

∗ Very good agreementamongall fitted values

∗ ATLAS-CONF-2014-008CDF note 11071CMS PAS TOP-13-014DØ note 6416



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CDF NEW CDF Top Mass

• New CDF update:

∗ The CDF collaboration just approved anew combination of measurements.

∗ All channels now updated with full dataset.CDF public note 11080

)2 (GeV/ctM150 160 170 180 190 200

0

11

CDF March’07 2.66± 12.40 2.20)±1.50 ±(

CDF combination * 0.93± 173.16 0.74)±0.57 ±(

syst)± stat ±(

CDF-II MET+jets 1.85± 173.93 1.26)±1.35 ±(

CDF-II track 9.46± 166.90 2.90)±9.00 ±(

CDF-II alljets * 1.96± 175.07 1.56)±1.19 ±(

CDF-I alljets 11.51± 186.00 5.70)±10.00 ±(

CDF-II lepton+jets 1.11± 172.85 0.98)±0.52 ±(

CDF-I lepton+jets 7.36± 176.10 5.30)±5.10 ±(

CDF-II dilepton * 3.25± 170.80 1.83)±2.69 ±(

CDF-I dilepton 11.41± 167.40 4.90)±10.30 ±(

Mass of the Top Quark

(* CDF preliminary)March 2014

/dof = 5.6/7 (58%)2χ

Mtop = 173.16 ± 0.57(stat) ± 0.74(syst)GeV

= 173.16 ± 0.93GeV

Analysis0

0.2

0.4

0.6

for

all m

easu

rem

ents

i w

eigh

t

∑ �/

i

wei

ght

CDF-II lepton+jets

CDF-II MET+jets

CDF-II allje

ts

CDF-I lepton+jets

CDF-II dile

pton

CDF-I dile

pton

CDF-I allje

ts

CDF-II tra

ck

March 2014CDF Preliminary

Red box: positive weightsGrey box: absolute value of

negative weights

• Last word on Mtop from CDF



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CDF Conclusions

• The Fermilab TEVATRON was shut downin September 2011∼ 10 fb−1 of data collected by experiments during Run II.

• The Collaborations are finalizing measurements of theTop Quark Mass using full datasets

• A selection of more recent ones has been presentedin this talk. Full details in

∗ www-cdf.fnal.gov/physics/new/top/publicmass.html

∗ www-d0.fnal.gov/Run2Physics/top/

• Excellent results from all decay channels.Uncertainty now everywhere dominated by systematics.

• Results from individual experiments haveprecisions by far beyond Run IIa goal.

• Tevatron competitive with LHC.

• It’s time for Mtop World Average

)−1Integrated Luminosity (pb

210 310 410

2(t

otal

) G

eV/c

t M∆

1

10

CDF Results

Run IIa LJ goal (TDR 1996)

(syst) fixed∆, L(stat) scales as 1/∆

L(total) scales as 1/∆2 = 1GeV/c

t/MtM∆

CDF Top Mass Uncertainty(all channels combined)

−11 fb −12 fb −15 fb −110 fb

Now : σMtop≃ 0.93GeV

LHC + TEVATRON, March 2014

Mtop = 173.34 ± 0.76GeV




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Backup



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CDF The Tevatron Experiments

CDF

DØ

• pp̄ collisions at 1.96 TeV (Run II, 2001-2011).

• Peak lumi≈ 4 · 1032cm−2s−1

• About 12 fb−1 delivered to experiments.

Acquired 10 fb−1 / experiment

• Collaborations :– Currently 400 + 400 members– 60 (CDF) + 70 (DØ) Institutions



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CDF Matrix Element Method

• Matrix Element (ME)

– Defineper-event probability by Leading Order ME of signal ( tt̄) and Bkg events as a functionof Mtop, JES and the expected fraction of signalftt̄ :

Pev (~y, ftt̄, Mtop, JES) = ftt̄ ·Ptt̄ (~y, Mtop, JES)+(1 − ftt̄) ·Pbkg (~y, JES)

Ptt̄ ∝1

N

∫

f(z1) f(z2) dz1 dz2︸︷︷︸

p.d.f .

W(~y, ~x, JES)︸︷︷︸

Transfer function

dσtt̄(~x, Mtop)︸︷︷︸

differentialx−section

– Pbkg totally analogous, butdσbkg(~x).

– Pev gives the probability for the observed event kinematics,~y, to arise from a signal or a bkgevent.

– N : Normalization factor

– f(z) : Parton density functions

– W (~y, ~x, JES) : Connect observed jets to partons. Give the probability forthe measuredjet momenta~y given corresponding parton momenta~x. Depend on the Jet Energy Scale.

– dσ(~x) : Include ME calculation and phase space. Depend onMtop for tt̄ events.

• Maximize sample likelihood L (~y, ftt̄, Mtop, JES) =∏

events

Pev



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CDF Template Method

• CDF, Lepton + Jets: χ2 expression formrecot (free parametersmreco

t , pfitT,i

andUfitj

)

χ2 =

(mjj − MW

)2

Γ2W

+

(mlν − MW

)2

Γ2W

+

(mjjb − mreco

t

)2

Γ2t

+

(mlνb − mreco

t

)2

Γ2t

+∑

i=l,jets

(pfitT,i

− pmeasT,i

)2

σ2i

+∑

j=x,y

(U

fitj

− Umeasj

)2

σ2j

• CDF, All-Hadronic : χ2 expression formrect (free parametersmrec

t and pfitT,i

)

χ2 =

(m

(1)jj

− MW

)2

Γ2W

+

(m

(2)jj

− MW

)2

Γ2W

+

(m

(1)jjb

− mrect

)2

Γ2t

+

(m

(2)jjb

− mrect

)2

Γ2t

+∑

i=jets

(pfitT,i

− pmeasT,i

)2

σ2i

∗ mjj , mlν : Invariant masses of dijet and lepton-neutrino systems

∗ mjjb, mlνb : Invariant masses of three-particle systems includingb-jets

∗ pmeasT,i

, σi : Measured transverse momenta of lepton, jets and uncertainties

∗ Umeasj

, σj : components of unclustered energy and uncertainties.

∗ MW , ΓW , Γt : Mass ofW boson and widths ofW and top quark



24✬

✫

✩

✪


• Uncertainties

Input measurements and uncertainties in GeV

CDF D0 ATLAS CMS World

Uncertainty l+jets di-l all jet EmissT

l+jets di-l l+jets di-l l+jets di-l all jet Combination

mtop 172.85 170.28 172.47 173.93 174.94 174.00 172.31 173.09 173.49 172.50 173.49 173.34

Stat 0.52 1.95 1.43 1.26 0.83 2.36 0.23 0.64 0.27 0.43 0.69 0.27

iJES 0.49 n.a. 0.95 1.05 0.47 0.55 0.72 n.a. 0.33 n.a. n.a. 0.24

stdJES 0.53 2.99 0.45 0.44 0.63 0.56 0.70 0.89 0.24 0.78 0.78 0.20

flavourJES 0.09 0.14 0.03 0.10 0.26 0.40 0.36 0.02 0.11 0.58 0.58 0.12

bJES 0.16 0.33 0.15 0.17 0.07 0.20 0.08 0.71 0.61 0.76 0.49 0.25

MC 0.56 0.36 0.49 0.48 0.63 0.50 0.35 0.64 0.15 0.06 0.28 0.38

Rad 0.06 0.22 0.10 0.28 0.26 0.30 0.45 0.37 0.30 0.58 0.33 0.21

CR 0.21 0.51 0.32 0.28 0.28 0.55 0.32 0.29 0.54 0.13 0.15 0.31

PDF 0.08 0.31 0.19 0.16 0.21 0.30 0.17 0.12 0.07 0.09 0.06 0.09

DetMod < 0.01 <0.01 <0.01 <0.01 0.36 0.50 0.23 0.22 0.24 0.18 0.28 0.10

b-tag 0.03 n.e. 0.10 n.e. 0.10 <0.01 0.81 0.46 0.12 0.09 0.06 0.11

LepPt 0.03 0.27 n.a. n.a. 0.18 0.35 0.04 0.12 0.02 0.14 n.a. 0.02

BGMC 0.12 0.24 n.a. n.a. 0.18 n.a. n.a. 0.14 0.13 0.05 n.a. 0.10

BGData 0.16 0.14 0.56 0.15 0.21 0.20 0.10 n.a. n.a. n.a. 0.13 0.07

Meth 0.05 0.12 0.38 0.21 0.16 0.51 0.13 0.07 0.06 0.40 0.13 0.05

MHI 0.07 0.23 0.08 0.18 0.05 <0.01 0.03 0.01 0.07 0.11 0.06 0.04

Total Syst 0.99 3.13 1.41 1.36 1.25 1.49 1.53 1.50 1.03 1.46 1.23 0.71

Total 1.12 3.69 2.01 1.85 1.50 2.79 1.55 1.63 1.06 1.52 1.41 0.76

Table 3: Uncertainty categories assignment for the input measurements and the result of the world m com-



tevatron cdf top quark massrencontres de moriond ew, la thuile, march 19, 2014 ... top quark mass...

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