Differential Top Cross-section MeasurementsALPS2017 Obergurgl
Michael Fentonon behalf of the ATLAS Collaboration
University of [email protected]
April 18, 2017
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 1 / 16
Outline
1 Motivation2 Analysis Strategy3 Uncertainties4 Results5 Summary
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 2 / 16
Why do differential measurements of tt̄ processes? [1/2]
The top quark is unique in the SM due to it’s large mass:
decay before hadronisation
→ only quark that can be studied in isolationprecision QCD test
same order as V.E.V in SM
→ mt ' 173 GeV, v = 246 GeV↪→ direct sensitivity to new physics
mt = ytv/√
2
∆mth ∼ −
m2
v 2
Λ
4π2
Top properties at the LHC
Top production & decay• Top production dominated by QCD production. EW
production provides direct access to Wtb vertex:
• In SM top decays to Wb:
4
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 3 / 16
Why do differential measurements of tt̄ processes? [2/2]
Major background to many interesting searches like tt̄H or SUSY
Not always well described in current MC generators→ Differential measurements crucial input to MC tuning efforts!
TOPQ-2014-15
Differential data very useful to theorists:
constraining EFT operators: TopFitter
gluon PDF at large x: Czakon et al
highly sensitive to NNLO effects Czakon et al
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 4 / 16
Outline
1 Motivation2 Analysis Strategy3 Uncertainties4 Results5 Summary
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 5 / 16
Analysis Strategy
1 Select events
Lepton+jets channelUtilize both resolved andboosted topologies
2 Estimate backgrounds
3 Reconstruct tops and tt̄ system
4 Unfold data
ICHEP Conference Note
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 6 / 16
Analysis Strategy
1 Select events
2 Estimate backgrounds
Data-driven QCD estimate andW+jetsMC based signal and otherbackgrounds
3 Reconstruct tops and tt̄ system
4 Unfold dataE
vent
s / G
eV
500
1000
1500
2000
2500
3000
3500 DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Resolved
[GeV]missTE
0 50 100 150 200
Dat
a/P
red.
0.81
1.2
ICHEP Conference Note
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 6 / 16
Analysis Strategy
1 Select events
2 Estimate backgrounds
3 Reconstruct tops and tt̄ system
Measure pt,hadT ,
∣∣y t,had∣∣
ptt̄T , mtt̄ ,
∣∣∣y tt̄∣∣∣ (resolved only)
4 Unfold data
ICHEP Conference Note
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 6 / 16
Analysis Strategy
1 Select events
2 Estimate backgrounds
3 Reconstruct tops and tt̄ system
4 Unfold data
Iterative Bayesian Unfolding(4 iterations)Unfold to particle level
Mig
ratio
n [%
]
0
10
20
30
40
50
60
70
80
90
100
[GeV] (detector level)t,had
Tp
[GeV
] (pa
rtic
le le
vel)
t,had
Tp 70 28 2
11 71 18 1
1 15 69 15
1 15 71 12
1 18 69 12
2 20 65 12
2 22 62 13
1 3 21 64 11
1 3 24 61 12
1 4 24 59 13
1 4 20 65 9
1 3 23 63 10
1 4 24 59 11
2 5 23 59 12
1 4 14 81
0 0
25
25
50
50
75
75
105
105
135
135
165
165
195
195
230
230
265
265
300
300
350
350
400
400
450
450
500
500
1000
1000
ATLAS SimulationPreliminaryResolved
ICHEP Conference Note
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 6 / 16
Resolved Selection
t tW
b
q
q
W
`
ν
b
= 1 lepton≥ 4 R=0.4 jet, ≥ 2 b-jet
No explicit requirement
pT > 25 GeV|η| < 2.5
pT > 25 GeV|η| < 2.5
pT > 25 GeV|η| < 2.5
pT > 25 GeV|η| < 2.5
pT > 25 GeV|η| < 2.5
Eve
nts
20
40
60
80
100
120
140
310×DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Resolved
Jet multiplicity
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Dat
a/P
red.
0.81
1.2
Eve
nts
/ GeV
500
1000
1500
2000
2500
3000
3500 DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Resolved
[GeV]missTE
0 50 100 150 200
Dat
a/P
red.
0.81
1.2
Eve
nts
/ GeV
200
400
600
800
1000
1200
1400
1600
1800 DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Resolved
[GeV]t,had
Tp
0 200 400 600 800 1000 D
ata/
Pre
d.0.8
11.2
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 7 / 16
Boosted Selection
t t
b
W q
q
W
`
ν
b
∆R < 2.0
∆R > 1.5
∆φ(`, thad) > 1.0
= 1 lepton≥ 1 R=1.0 jet, ≥ 1 top tag, ≥ 1 R=0.4 jet, ≥ 1 b-jet
EmissT +mW
T > 60 GeV
EmissT > 20 GeV
pT > 25 GeV|η| < 2.5
pT > 25 GeV|η| < 2.5
pT > 300 GeV
|η| < 2.0
lep_pt
0 50 100 150 200 250 300 350 400 450 500
Eve
nts
/ GeV
20
40
60
80
100DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Boosted
[GeV]T
Lepton p
0 100 200 300 400 500
Dat
a/P
red.
0.60.8
11.21.4
ljet_m
0 50 100 150 200 250 300
Eve
nts
/ GeV
20
40
60
80
100
120
140
160DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Boosted
Large-R jet mass [GeV]
0 100 200 300
Dat
a/P
red.
0.60.8
11.21.4
hadtop_pt_varbin_logscale
400 600 800 1000 1200 1400
Eve
nts
/ GeV
2−10
1−10
1
10
210
310 DatattSingle topW+jetsZ+jetsDibosonVtt
MultijetsStat.+Syst. Unc.
-1 = 13 TeV, 3.2 fbsATLAS Preliminary
Boosted
[GeV]t,had
Tp
500 1000 1500 D
ata/
Pre
d.0.60.8
11.21.4
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 8 / 16
Outline
1 Motivation2 Analysis Strategy3 Uncertainties4 Results5 Summary
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 9 / 16
Uncertainties
[GeV]t,had
Tp
0 100 200 300 400 500 600 700 800 900 1000
Fra
ctio
nal U
ncer
tain
ty [%
]
60−
40−
20−
0
20
40
60
Stat.+Syst. Unc. Stat. Unc.Flavor Tagging JES/JERBackgrounds IFSR, PDF, MC Stat.Hadronisation Hard Scattering
ATLAS Preliminary-1 = 13 TeV, 3.2 fbs
Resolved
Fiducial phase-space
Relative cross-section
[GeV]t,had
Tp
400 600 800 1000 1200 1400
Fra
ctio
nal U
ncer
tain
ty [%
]
80−
60−
40−
20−
0
20
40
60
80
Stat.+Syst. Unc. Stat. Unc.Large-R jet , Small-R jet
T
missLepton, EBackgrounds IFSR, PDF, MC Stat.Hadronisation Hard Scattering
ATLAS Preliminary-1 = 13 TeV, 3.2 fbs
Boosted
Fiducial phase-space
Relative cross-section
Jet energy scale and b-tagging uncertainties largest in resolved
Large-R jets systematics are dominant in boosted analysis
Generator systematics important in both analyses
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 10 / 16
Outline
1 Motivation2 Analysis Strategy3 Uncertainties4 Results5 Summary
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 11 / 16
Top pT /
GeV
t,had
T /
d p
ttσ d
⋅ ttσ
1/
5−10
4−10
3−10
2−10
1−10
1
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
1.4
[GeV]t,had
Tp
0 200 400 600 800 1000
Dat
aP
redi
ctio
n
0.81
1.21.4
/ G
eVt,h
ad
T /
d p
ttσ d
⋅ ttσ
1/
5−10
4−10
3−10
2−10
1−10
1
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Boosted
Dat
aP
redi
ctio
n
1
2
[GeV]t,had
Tp
400 600 800 1000 1200 1400D
ata
Pre
dict
ion
0
1
2
MC predicts harder spectrum than observed in data
Similar slope seen in both regions, as has been observed previously
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 12 / 16
Top Rapidity|t
| / U
nit |
yt
/ d
|yttσ
d
⋅ ttσ1/
0.2
0.4
0.6
0.8
1
1.2
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.9
1
1.1
|t,had
|y
0 0.5 1 1.5 2 2.5
Dat
aP
redi
ctio
n
0.9
1
1.1
|t| /
Uni
t |y
t /
d |y
ttσ d
⋅ ttσ
1/
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Boosted
Dat
aP
redi
ctio
n
0.5
1
1.5
|t,had
|y
0 0.5 1 1.5 2D
ata
Pre
dict
ion
00.5
1
1.5
Good agreement with all generators
Statistics is dominant uncertainty
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 13 / 16
tt̄ kinematics /
GeV
tt /
d m
ttσ d
⋅ ttσ
1/
5−10
4−10
3−10
2−10
1−10 Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.5
1
1.5
[GeV]ttm
500 1000 1500 2000 2500 3000
Dat
aP
redi
ctio
n
0.5
1
1.5
/ G
eVtt T
/ d
pttσ
d
⋅ ttσ1/
4−10
3−10
2−10
1−10
1
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
[GeV]ttT
p
0 100 200 300 400 500 600 700 800
Dat
aP
redi
ctio
n
0.8
1
1.2
|tt| /
Uni
t |y
tt /
d |y
ttσ d
⋅ ttσ
1/
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
|tt|y
0 0.5 1 1.5 2 2.5
Dat
aP
redi
ctio
n
0.8
1
1.2
Powheg gives best description of ptt̄T and mtt̄
Expected high dependence of ptt̄T on hdamp parameter and radiation settings
Powheg+Herwig++ much better at high∣∣y tt̄
∣∣
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 14 / 16
Outline
1 Motivation2 Analysis Strategy3 Uncertainties4 Results5 Summary
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 15 / 16
Summary
Differential cross sections of tt̄ production important in SM and BSMphysics, experiment and theory, both as a signal and a background
/ G
eVt,h
ad
T /
d p
ttσ d
⋅ ttσ
1/
5−10
4−10
3−10
2−10
1−10
1
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
1.4
[GeV]t,had
Tp
0 200 400 600 800 1000
Dat
aP
redi
ctio
n
0.81
1.21.4
Modelling of tt̄ process is generallygood
But top pT slope from Run1 stillremainsNNLO corrections may accountfor this
Biggest systematic is often the MCrelated ones
Can use these results to improvethe MC going forward
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 16 / 16
BACKUP
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 17 / 16
Run 1 NNLO Comparison
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 18 / 16
Resolved 8TeV vs 13TeV /
GeV
t,had
T /
d p
ttσ d
⋅ ttσ
1/
-510
-410
-310
-210
-110
1
Data
t=mdampPWG+PY6 h
t=mdampPWG+PY8 hMC@NLO+HW AUET2MadGraph+PY6 P2011CPWG+HW6 AUET2Stat. unc.Stat.+Syst. unc.
ATLAS Fiducial phase-space-1 = 8 TeV, 20.3 fbs
[GeV]t,had
Tp
0 200 400 600 800 1000
Dat
aP
redi
ctio
n
0.81
1.21.4
/ G
eVt,h
ad
T /
d p
ttσ d
⋅ ttσ
1/
5−10
4−10
3−10
2−10
1−10
1
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n0.8
1
1.2
1.4
[GeV]t,had
Tp
0 200 400 600 800 1000
Dat
aP
redi
ctio
n
0.81
1.21.4
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 19 / 16
Boosted 8TeV vs 13TeV
/ G
eVt,h
ad
T /
d p
ttσ d
⋅ ttσ
1/
5−10
4−10
3−10
2−10
1−10
1
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Boosted
Dat
aP
redi
ctio
n
1
2
[GeV]t,had
Tp
400 600 800 1000 1200 1400
Dat
aP
redi
ctio
n
0
1
2
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 20 / 16
Common Object Definitions
Electrons; gradient isolation, tight, |η| < 2.47 excluding crack, pT > 25GeV,|dBL
0 sig | < 5, |zBL0 sin θ| < 0.5mm
Muons; gradient isolation, medium, |η| < 2.5, pT > 25GeV, |dBL0 sig | < 3,
|zBL0 sin θ| < 0.5mm
Small Jets; anti-kT R=0.4, |η| < 2.5, pT > 25GeV, with JVT cut andcalibration
Large Jets; anti-kT R=1.0, |η| < 2.0, pT > 300GeV, trimmed (Rsub = 0.2 &fcut = 0.05), m > 50 GeV, pT < 1500 GeV
b-tags; MV2c20 > −0.4434 ( 77% working point )
Top-tags; pT dependent large jet mass and τ32 cuts, with 80% efficiencyworking point ATL-PHYS-PUB-2015-053
At particle level flat m > 100 GeV, τ32 < 0.75 is used to define fiducial volume
Overlap removal: Jets within ∆R < 0.2 of electron; Electrons within∆R < 0.4 of surviving jets; Jets with ∆R < 0.4 of a muon removed if < 3tracks; otherwise muon removed
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 21 / 16
Samples
Physics process Generator Cross-section PDF set for Parton shower Tunenormalisation hard process
tt̄ Signal Powheg-Box v2 NNLO+NNLL CT10 Pythia 6.428 Perugia2012tt̄ PS syst. Powheg-Box v2 NNLO+NNLL CTEQ6L1 Herwig++2.7.1 UE-EE-5tt̄ ME syst. MadGraph5_ NLO CT10 Herwig++2.7.1 UE-EE-5
aMC@NLOtt̄ rad. syst. Powheg-Box v2 NNLO+NNLL CT10 Pythia 6.428 ’radHi/Lo’s top t-channel Powheg-Box v1 NLO CT10f4 Pythia 6.428 Perugia2012s top s-channel Powheg-Box v2 NLO CT10 Pythia 6.428 Perugia2012s top Wt-channel Powheg-Box v2 NLO+NNLL CT10 Pythia 6.428 Perugia2012tt̄+W/Z/WW MadGraph5_ NLO NNPDF2.3LO Pythia 8.186 A14
aMC@NLOW(→ `ν)+ jets Sherpa 2.1.1 NNLO CT10 Sherpa SherpaZ(→ ` ¯̀)+ jets Sherpa 2.1.1 NNLO CT10 Sherpa SherpaWW,WZ,ZZ Sherpa 2.1.1 NLO CT10 Sherpa Sherpa
Table 1: Summary of MC samples, showing the hard process generator, cross-section normalisation precision,PDF choice as well as the parton shower and the corresponding tune used in the analysis. The Pythia andHerwig++ models use the CTEQ6L1 PDFs for their respective parton shower PDFs.
• The factorisation and hadronisation scales are varied down by a factor of 0.5, simultaneously thehdamp parameter is increased to 2mtop. Furthermore the ’radHi’ tune variation from the P2012tune set is used.
• The factorisation and hadronisation scales are varied up by a factor of 2.0 while the hdamp param-eter is unchanged. Furthermore the ’radLo’ tune variation from the P2012 tune set is used.
The tt̄ samples are normalised to σtt̄ = 831.76+46.45−50.85 pb (scale, PDF and αS ), evaluated using the
Top++2.0 program [34]. The calculation includes next-to-next-to-leading-order (NNLO) QCD correc-tions and resums next-to-next-to-leading logarithmic (NNLL) soft gluon terms [35–40].
Events containing W or Z bosons in association with jets are simulated using the Sherpa 2.1.1 [41]generator. Matrix elements are calculated for up to two partons at NLO and four partons at LO usingthe Comix [42] and OpenLoop [43] matrix element generators and merged with the Sherpa partonshower [44] using the ME+PS@NLO prescription [45]. The CT10 PDF set is used in conjunctionwith dedicated parton shower tuning developed by the authors of Sherpa. The W/Z+jets events arenormalised to the NNLO cross-sections [46].
Diboson processes with one of the bosons decaying hadronically and the other leptonically are sim-ulated using the Sherpa 2.1.1 generator [41, 47]. They are calculated for up to one (ZZ) or 0 (WW,WZ) additional partons at NLO and up to three additional partons at LO using the Comix [42] andOpenLoops [43] matrix element generators and merged with the Sherpa parton shower [44] using theME+PS@NLO prescription [45]. The CT10 PDF set is used in conjunction with dedicated partonshower tuning developed by the Sherpa authors. The generator cross-sections are used in this case(already at NLO).
The tt̄ + electroweak processes (tt̄ + W/Z/WW) are simulated using the MadGraph5_aMC@NLOgenerator at LO interfaced to the Pythia 8.186 parton shower model [48]. The matrix elements aresimulated with up to two (tt̄ + W), one (tt̄ + Z) or no (tt̄ + WW) extra partons. The ATLAS underlyingevent tune A14 is used together with the NNPDF2.3LO PDF set. The events are normalised to theirrespective NLO cross-sections [49].
A summary of the MC samples used in this analysis is shown in Tab. 1.
5
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 22 / 16
Unfolding procedure
Using the Iterative Bayesian method in RooUnfold with 4 iterations
Master formula:
dσfid
dX i≡ 1
L ·∆X i· f ieff ·
∑j
M−1ij · f
jacc ·
(N j
reco − N jbkg
)(1)
f ieff ≡(
Npart
Nreco&part
)i
,f jacc ≡(Nreco&part
Nreco
)j
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 23 / 16
Uncertainties for Absolute Spectra
[GeV]t,had
Tp
0 100 200 300 400 500 600 700 800 900 1000
Fra
ctio
nal U
ncer
tain
ty [%
]
60−
40−
20−
0
20
40
60
Stat.+Syst. Unc. Stat. Unc.Flavor Tagging JES/JERBackgrounds IFSR, PDF, MC Stat.Hadronisation Hard Scattering
ATLAS Preliminary-1 = 13 TeV, 3.2 fbs
Resolved
Fiducial phase-space
Absolute cross-section
[GeV]t,had
Tp
400 600 800 1000 1200 1400
Fra
ctio
nal U
ncer
tain
ty [%
]80−
60−
40−
20−
0
20
40
60
80
Stat.+Syst. Unc. Stat. Unc.Large-R jet , Small-R jet
T
missLepton, EBackgrounds IFSR, PDF, MC Stat.Hadronisation Hard Scattering
ATLAS Preliminary-1 = 13 TeV, 3.2 fbs
Boosted
Fiducial phase-space
Absolute cross-section
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 24 / 16
Top pT (Absolute) /
GeV
[pb]
t,had
T /
d p
ttσd
3−10
2−10
1−10
1
10
210
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
[GeV]t,had
Tp
0 200 400 600 800 1000
Dat
aP
redi
ctio
n
0.8
1
1.2 /
GeV
[pb]
t,had
T /
d p
ttσd
4−10
3−10
2−10
1−10
1Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Boosted
Dat
aP
redi
ctio
n
1
2
[GeV]t,had
Tp
400 600 800 1000 1200 1400
Dat
aP
redi
ctio
n
0
1
2
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 25 / 16
Top Rapidity (Absolute)| [
pb]
t| /
Uni
t |y
t /
d |y
ttσd
20
40
60
80
100
120Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
|t,had
|y
0 0.5 1 1.5 2 2.5
Dat
aP
redi
ctio
n
0.8
1
1.2| [
pb]
t| /
Uni
t |y
t /
d |y
ttσd
1
2
3
4
5Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Boosted
Dat
aP
redi
ctio
n
0.5
1
1.5
|t,had
|y
0 0.5 1 1.5 2
Dat
aP
redi
ctio
n
00.5
1
1.5
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 26 / 16
tt̄ kinematics (Absolute) /
GeV
[pb]
tt /
d m
ttσd
3−10
2−10
1−10
1
10 Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
1
1.5
[GeV]ttm
500 1000 1500 2000 2500 3000
Dat
aP
redi
ctio
n
1
1.5
/ G
eV [p
b]tt T
/ d
pttσ
d
2−10
1−10
1
10
210
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
[GeV]ttT
p
0 100 200 300 400 500 600 700 800
Dat
aP
redi
ctio
n
0.8
1
1.2
| [pb
]tt
| / U
nit |
ytt
/ d
|yttσ
d
20
40
60
80
100
120
140
160
Data
t=mdampPWG+PY6 h radHit=2mdampPWG+PY6 h
radLot=mdampPWG+PY6 h
t=mdampPWG+PY8 h
t=mdampPWG+H++ haMC@NLO+H++Stat. unc.Stat.+Syst. unc.
ATLAS Preliminary Fiducial phase-space-1 = 13 TeV, 3.2 fbs
Resolved
Dat
aP
redi
ctio
n
0.8
1
1.2
|tt|y
0 0.5 1 1.5 2 2.5
Dat
aP
redi
ctio
n
0.8
1
1.2
Michael Fenton Differential Top Cross-section Measurements April 18, 2017 27 / 16