jet measurements at the lhc and impact on s and pdfs · jet measurements at the lhc and impact on s...

Jet measurements at the LHC andimpact on αs and PDFs

Javier Llorente,on behalf of the ATLAS and CMS Collaborations.

IHEP Beijing

SM@LHC 2018, Berlin

Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 1 / 25

Outline of the talk

Run-I measurements

ATLAS inclusive jets at√s = 8 TeV

ATLAS determination of αs from TEEC.

CMS inclusive jets at√s = 8 TeV.

Determination of αs .

Determination of parton distribution functions.

CMS triple-differential cross sections at√s = 8 TeV.

Determination of αs and PDFs

Run-II measurements

ATLAS inclusive and dijet cross sections at√s = 13 TeV.

CMS inclusive cross section at√s = 13 TeV.

Summary of αs determinations.


ATLAS inclusive jet cross sections at√s = 8 TeV [JHEP 09 (2017) 020]

Double differential cross section for 70 GeV ≤ pT ≤ 2.5 TeV and |y | < 3.0.Anti-kt jets with R = 0.4 and R = 0.6 are considered.Data corrected for detector effects.NLO predictions corrected for electroweak and non-perturbative effects.

[GeV]T,jet

p

70 210 210×23

103

10×2

d|y

| [p

b/G

eV

]T

,jet

/dp

σ2

d

8−10

7−10

6−10

5−10

4−10

3−10

2−10

1−10

1

10

210

310

410

510

|y| <0.5

)00.5 10× |y| <1.0 (≤0.5

)11.0 10× |y| <1.5 (≤1.0

)10.5 10× |y| <2.0 (≤1.5

)21.0 10× |y| <2.5 (≤2.0

)20.5 10× |y| <3.0 (≤2.5

MMHT2014EW k⊗Pythia8AU2CT10

NPk ⊗NLO QCD

ATLAS

1= 8 TeV, 20.2 fbs

R= 0.4tantik

[GeV]T,jet

p70 210 210×2 310 310×2

Rel

ativ

e un

certa

inty

0.4−

0.2−

0

0.2

0.4

0.6

Total systematic uncertaintyJet energy resolutionJet energy scaleOtherStatistics

ATLAS

1= 8 TeV, 20.2 fbs R= 0.4tantik

|y| <0.5

[GeV]T,jet

p70 210 210×2 310 310×2

Rel

ativ

e N

LO Q

CD

unc

erta

inty

0.3−

0.2−

0.1−

0

0.1

0.2

0.3

0.4NLO QCD

sα

CT14 PDFScale variationTotal

= 8 TeVs R= 0.4tantik

|y| <0.5T,jet,max= P

Fµ=

Rµ


ATLAS inclusive jet cross sections at√s = 8 TeV [JHEP 09 (2017) 020]

NLO pQCD theoretical predictions are investigated for different PDFsT

he

ory

/Da

ta

0.7

0.8

0.9

1

1.1

1.2

1.3

1.4 |y|<0.5

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5|y|<1.0≤0.5

[GeV]T,jet

p70 210 210×2 310 310×2

0.80.9

11.11.21.31.41.51.6

|y|<1.5≤1.0

Th

eo

ry/D

ata

0.60.8

1

1.21.4

1.6

1.82

2.2 |y|<2.0≤1.5

0.40.60.8

11.21.41.61.8

22.2

|y|<2.5≤2.0

[GeV]T,jet

p70 210 210×2 310

0.5

1

1.5

2

2.5

3 |y|<3.0≤2.5

ATLAS

1L = 20.2 fb

= 8 TeVs

R = 0.6tantik

Data

NLO QCDPythia8 AU2CT10

NP k⊗ EW k⊗

max

T, jet = p

Fµ =

Rµ

CT14

HERAPDF2.0

NNPDF3.0

MMHT2014

Better overall description for R = 0.6.

CT14, NNPDF3.0 and MMHT 2014 give similar descriptions.

HERAPDF 2.0 deviates slightly.


ATLAS determination of αs from TEEC [Eur. Phys. J. 77 (2017) 872]

TEEC: The xT-weighted distribution of differences in ϕ between jets

i and j , with xTi =ETi∑k ETk

. Measured in intervals of pT1 + pT2.

1

σ

dΣ

d(cosφ)=

1

σ

∑ij

∫dσ

dxTidxTjd(cosφ)xTixTjdxTidxTj

And the azimuthal asymmetry ATEEC is defined as

1

σ

dΣasym

d(cosφ)≡

1

σ

dΣ

d(cosφ)

∣∣∣∣φ

−1

σ

dΣ

d(cosφ)

∣∣∣∣π−φ

)φ

/d(c

os

Σ)

dσ

(1/

210

110

1

10 Data 2012

Pythia8

Herwig++

Sherpa

ATLAS

1 = 8 TeV; 20.2 fbs

jets R = 0.4tantik

> 1400 GeVT2H

φcos

1 0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8 1

MC

/ D

ata

0.5

1

1.5 syst. unc.⊕Data stat.

)φ

/d(c

os

asy

mΣ

) d

σ(1

/3

10

210

110

1 Data 2012

Pythia8

Herwig++

Sherpa

ATLAS

1 = 8 TeV; 20.2 fbs

jets R = 0.4tantik

> 1400 GeVT2H

φcos

1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

MC

/ D

ata

0

1

2 syst. unc.⊕Data stat.



Comparison with NLO pQCD predictions from NLOJet++

0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8

Da

ta /

Th

eo

ry

0.7

0.8

0.9

1

1.1

1.2 < 850 GeV

T2800 GeV < H

0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8

0.7

0.8

0.9

1

1.1

1.2

< 900 GeVT2

850 GeV < H

0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8

Data

/ T

heory

0.7

0.8

0.9

1

1.1

1.2 < 1000 GeV

T2900 GeV < H

0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8

0.7

0.8

0.9

1

1.1

1.2

< 1100 GeVT2

1000 GeV < H

φcos 0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8

Data

/ T

heory

0.7

0.8

0.9

1

1.1

1.2 < 1400 GeV

T21100 GeV < H

φcos 0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8

0.7

0.8

0.9

1

1.1

1.2

> 1400 GeVT2H

ATLAS

1 = 8 TeV; 20.2 fbs

NNPDF 3.0 (NNLO)

TEEC Function

Exp. uncertainty

Nonscale unc.

Theo. uncertainty

Good agreement within experimental and theoretical uncertainties.

QCD scale uncertainties largely dominate the determination of αs .



Determination of αs from a χ2 fit

χ2(αs , ~λ) =

∑i

(xi − Fi (αs , ~λ))2

∆x2i + ∆τ 2

i

+∑k

λ2k ; where Fi (αs , ~λ) = ψi (αs )

(1 +

∑k

λkσ(i)k

)

MMHT 2014

CT14

NNPDF 3.0

HERAPDF 2.0

)Z

(mS

α

0.105 0.11 0.115 0.12 0.125

PDF uncertaintyTotal uncertaintyPDG 2016PDG uncertainty

ATLAS1 = 8 TeV; 20.2 fbsTEEC.

MMHT 2014

CT14

NNPDF 3.0

HERAPDF 2.0

)Z

(mS

α

0.112 0.114 0.116 0.118 0.12 0.122 0.124 0.126

PDF uncertaintyTotal uncertaintyPDG 2016PDG uncertainty

ATLAS1 = 8 TeV; 20.2 fbsATEEC.

)φ

/d(c

os

Σ)d

σ(1

/

410

310

210

110

1

Data (exp. unc.)

NLO pQCD (th. unc.)

ATLAS 1 = 8 TeV; 20.2 fbs

jets R = 0.4tantik

) = 0.1209Z

(ms

partialα

< 850 GeVT2800 GeV < H

NNPDF 3.0 (NNLO)

φcos

0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

Da

ta /

Th

eo

ry0.5

1

1.5

TEEC: αs (mZ ) = 0.1162 ± 0.0011 (exp.)+0.0084−0.0070(theo.)

ATEEC: αs (mZ ) = 0.1196 ± 0.0013 (exp.)+0.0075−0.0045(theo.)


CMS inclusive jet cross sections at√s = 8 TeV [JHEP 03 (2017) 156]

Double differential cross section for 21 GeV ≤ pT ≤ 2.5 TeV (R = 0.7)

Determination of αs and QCD analysis of the data.

Cross section ratios to 2.76 TeV and 7 TeV data are also considered

[GeV]T

Jet p30 40 100 200 300 1000 2000

GeVpb

dyT

dpσ2 d

7−10

4−10

1−10

210

510

810

1110

1410

1710 8 TeV

CMS

21

-1 = 5.6 pbint

Open: L-1 = 19.7 fbintFilled: L

EWK ⊗ NP ⊗CT10 NLO NP ⊗CT10 NLO

)6 10×|y| < 0.5 ( )5 10×0.5 < |y| < 1.0 ( )4 10×1.0 < |y| < 1.5 ( )3 10×1.5 < |y| < 2.0 ( )2 10×2.0 < |y| < 2.5 ( )1 10×2.5 < |y| < 3.0 ( )0 10×3.2 < |y| < 4.7 (



Ratios of the 8 TeV data to 2.76 TeV and TeV cross sections are studied

(GeV)T

Jet p200 300 400 1000 2000

(8T

eV

)dy

Tdp

σ2

d(7

TeV

) /

dy

Tdp

σ2

d

0

0.2

0.4

0.6

0.8

1

EWK)⊗Data/(NP

CT10 Theo. prediction

CT10 PDF uncertainty

CT10

NNPDF3.0

ABM11

HERAPDF1.5

MMHT14

|y| < 0.5

CMS

(GeV)T

Jet p80 100 200 300 400 500

(8 Te

V)dy T

dpσ2 d

(2.7

6 TeV

) /

dy Tdp

σ2 d

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Data/NPCT10 Theo. predictionCT10 PDF uncertaintyNNPDF3.0ABM11HERAPDF1.5MMHT14

|y| < 0.5

CMS

(GeV)T

Jet p200 300 400 1000 2000

Data

/Theory

0

0.5

1

1.5 |y| < 0.5

CMS

EWK)⊗Data/(NP

CT10 Theo. prediction

CT10 PDF uncertainty

NNPDF3.0

ABM11

HERAPDF1.5

MMHT14

(GeV)T

Jet p80 100 200 300 400 500

Data

/ The

ory

0

0.5

1

1.5

2

2.5

3

3.5

|y| < 0.5

CMS

Data/NPCT10 Theo. predictionCT10 PDF uncertaintyNNPDF3.0ABM11HERAPDF1.5MMHT14



The strong copuling constant is determined by minimizing the χ2 function

χ2[αs(mZ )] = (D − T [αs(mZ )])T C−1 (D − T [αs(mZ )]) ; C =∑theo

Ci +∑exp

Cj

(GeV)T

Jet p80 100 200 300 1000 2000

Ratio

to C

T10

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

|y| < 0.5CT10 NLO (R = 0.7)tanti-k

(8TeV)-119.7 fbCMS

) = 0.1120Z

(MSα)

Z(MSα

) = 0.1270Z

(MSα) = 0.1180

Z(MSα

EWK)⊗ NP ⊗Data/(NLO

(GeV)T

Jet p80 90100 200 300 400 500

Ratio

to C

T10

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.5 < |y| < 3.0CT10 NLO (R = 0.7)tanti-k

(8TeV)-119.7 fbCMS

) = 0.1120Z

(MSα)

Z(MSα

) = 0.1270Z

(MSα) = 0.1180

Z(MSα

EWK)⊗ NP ⊗Data/(NLO

)Z

(MSα0.113 0.116 0.119 0.123 0.127

2 χ

190

195

200

- 0.0032

+ 0.0029) = 0.1164Z

(MSα

) = (1, 1)µ/F

µ, µ/R

µ(

= 186.5/185Bins/Nmin2χ

CMS (8TeV)-119.7 fb

)]Z

(MSα[2χPolynomial Fit

αs(mZ ) = 0.1164+0.0014−0.0015 (exp.)+0.0059

−0.0041(theo.)



Determination of the PDFs, with initial scale Q20 = 1.9 GeV2.

The data constrains the gluon and down-valence quark parton densities.

1

2

3

4

1

2

3

4CMS NLO HERAPDF Method (Hessian)

Q2=1.9 GeV2

HERA I+II DIS + CMS jets 8 TeV

HERA I+II DIS

x •

g (

x, Q

2 )

x

Fra

ct. u

nce

rt.

-0.4

-0.2

0

0.2

0.4

10-4

10-3

10-2

10-1

-0.4

-0.2

0

0.2

0.4

10-4

10-3

10-2

10-1

0.2

0.4

0.6

0.2

0.4

0.6CMS NLO HERAPDF Method (Hessian)

Q2=1.9 GeV2

HERA I+II DIS + CMS jets 8 TeV

HERA I+II DIS

x •

dv

(x, Q

2 )

x

Fra

ct. u

nce

rt.

-0.4

-0.2

0

0.2

0.4

10-4

10-3

10-2

10-1

-0.4

-0.2

0

0.2

0.4

10-4

10-3

10-2

10-1

xg(x) = Ag xBg (1 − x)Cg (1 + Eg x

2) − A′g xB′g (1 − x)

C′g

xuv (x) = Auv xBuv (1 − x)Cuv (1 + Duv x + Euv x

2)

xdv (x) = Adv xBdv (1 − x)Cdv (1 + Ddv x)

xU(x) = AUxBU (1 − x)CU (1 + DUx)

xD(x) = ADxBD (1 − x)CD (1 + DDx + EDx

2)

Data sets Partial χ2/Ndp

HERA I+II neutral current e+p, Ep = 920 GeV 376/332HERA I+II neutral current e+p, Ep = 820 GeV 61/63HERA I+II neutral current e+p, Ep = 575 GeV 197/234HERA I+II neutral current e+p, Ep = 460 GeV 204/187HERA I+II neutral current e−p 219/159HERA I+II charged current e+p 41/39HERA I+II charged current e−p 50/42CMS inclusive jets 8 TeV 0 < y < 0.5 53/36

0.5 < y < 1.0 34/361.0 < y < 1.5 35/351.5 < y < 2.0 52/292.0 < y < 2.5 49/242.5 < y < 3.0 4.9/18

Correlated χ2 94Global χ2/Ndof 1471/1216


CMS triple-differential at√s = 8 TeV [Eur. Phys. J. C 77 (2017) 746]

Triple differential cross sections as a function of

pT ,avg =1

2(pT1 + pT2); y∗ =

1

2|y1 − y2|; yb =

1

2|y1 + y2|

y∗=

1 2|y 1−y 2|

yb =12 |y1 + y2|

0 1 2 30

1

2

3

1000200 300 500pT, avg [GeV]

10 4

10 3

10 2

10 1

100

101

102

103

104

105

106

107

108

d3

dpT,

avgd

y bdy

* [p

b/Ge

V]

19.7 fb 1 (8 TeV)

NLOJET++ (NLO EW NP)NNPDF 3.0

= pT, maxe0.3y*

anti kt R = 0.7

CMS 0 yb < 1 0 y* < 1 (×102)0 yb < 1 1 y* < 2 (×102)0 yb < 1 2 y* < 3 (×101)1 yb < 2 0 y* < 1 (×101)1 yb < 2 1 y* < 2 (×101)2 yb < 3 0 y* < 1 (×100)

Six different configurations (y∗, yb) are probed:

Relative angular configuration: back to back, z-boosted (yb)

Angle with respect to the z-axis: containment in the transverse plane (y∗)



Ratios to NLO predictions, corrected for NP and EW effects

1000200 300 500pT, avg [GeV]

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Ratio

to N

NPD

F 3.

0 N

LOEW

NP

0 yb < 10 y* < 1

CMS19.7 fb 1 (8 TeV)

DataExperimental uncertaintyTheoretical uncertaintyCT14 NLO EW NPMMHT 2014 NLO EW NPABM11 NLO EW NP

1000200 300 500pT, avg [GeV]

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Ratio

to N

NPD

F 3.

0 N

LOEW

NP

0 yb < 11 y* < 2



200 300 500pT, avg [GeV]

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Ratio

to N

NPD

F 3.

0 N

LOEW

NP

0 yb < 12 y* < 3



1000200 300 500pT, avg [GeV]

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Ratio

to N

NPD

F 3.

0 N

LOEW

NP

1 yb < 20 y* < 1



200 300 500pT, avg [GeV]

0.4

0.6

0.8

1.0

1.2

1.4

1.6Ra

tio to

NNP

DF

3.0

NLO

EWNP

1 yb < 21 y* < 2



200 300pT, avg [GeV]

0.4

0.6

0.8

1.0

1.2

1.4

1.6

Ratio

to N

NPD

F 3.

0 N

LOEW

NP

2 yb < 30 y* < 1



Reasonable agreement for most of the phase space, except for ABM11.Discrepancies for boosted configurations observed at high pT ,avg

High-x region of the PDF ⇒ potential for PDF constrainingJavier Llorente SM@LHC 2018 - Jets, αs and PDFs 13 / 25


Fits to the PDFs performed at Q20 = 1.9 GeV2 DGLAP−−−−−−→ Q2 = 104 GeV2.

Gluon parton density most constrained by these data.Simultaneous determination of αs(mZ ) (additional free parameter)

0.00.51.01.52.02.53.03.54.0

xg(x

,Q2 )

HERAPDF method (Hessian)

Q 2= 1.9 GeV2

CMS HERA I+II DISHERA I+II DIS + CMS dijets

10 4 10 3 10 2 10 1x

0.40.20.00.20.4

Rel.

unce

rt.

0

20

40

60

80

100

xg(x

,Q2 )

HERAPDF method (Hessian)

Q 2= 104 GeV2

CMS HERA I+II DISHERA I+II DIS + CMS dijets

10 4 10 3 10 2 10 1x

0.40.20.00.20.4

Rel.

unce

rt.

xg(x) = Ag xBg (1 − x)Cg − A′g x

B′g (1 − x)C′g

xuv (x) = Auv xBuv (1 − x)Cuv (1 + Duv x + Euv x

2)

xdv (x) = Adv xBdv (1 − x)Cdv (1 + Ddv x)

xU(x) = AUxBU (1 − x)CU (1 + DUx)

xD(x) = ADxBD (1 − x)CD

HERA data HERA & CMS data

Data set ndata χ2p χ2

p/ndata χ2p χ2

p/ndata

NC HERA-I+II e+p Ep = 920 GeV 332 382.44 1.15 406.45 1.22NC HERA-I+II e+p Ep = 820 GeV 63 60.62 0.96 61.01 0.97NC HERA-I+II e+p Ep = 575 GeV 234 196.40 0.84 197.56 0.84NC HERA-I+II e+p Ep = 460 GeV 187 204.42 1.09 205.50 1.10NC HERA-I+II e−p 159 217.27 1.37 219.17 1.38CC HERA-I+II e+p 39 43.26 1.11 42.29 1.08CC HERA-I+II e−p 42 49.11 1.17 55.35 1.32CMS triple-differential dijet 122 — — 111.13 0.91

Data set(s) ndof χ2 χ2/ndof χ2 χ2/ndof

HERA data 1040 1211.00 1.16 — —HERA & CMS data 1162 — — 1372.52 1.18

αs(mZ ) = 0.1199± 0.0015 (exp.)+0.0031−0.0020 (theo.)


ATLAS cross sections at√s = 13 TeV [arXiv:1711.02692 (hep-ex)]

Measurement of inclusive and dijet cross sections (anti-kt R = 0.4)Inclusive jets: 100 GeV < pT < 3.5 TeV; |y | < 3.0.Dijets: 300 GeV < mjj < 9 TeV; y∗ < 3, with HT2 > 200 GeVComparison with NLO and NNLO predictions with different scale choices.

Inclusive:d2σ

dpTdy; Dijets:

d2σ

dmjjdy∗ , with y∗ =1

2|y1 − y2|

[GeV]Tp

210 310

[pb/

GeV

]y

d Tp/dσ2 d

21−10

18−10

15−10

12−10

9−10

6−10

3−10

1

310

610

910

1210

201706241336

ATLAS-1fb3.2 --1nb81 = 13 TeV, s

=0.4R tanti-k

uncertaintiesSystematic

EW corr.×Non-pert. corr. ×NLOJET++ (CT14 PDF)

)0 10×| < 0.5 (y|)-3 10×| < 1.0 (y |≤0.5 )-6 10×| < 1.5 (y |≤1.0

)-9 10×| < 2.0 (y |≤1.5 )-12 10×| < 2.5 (y |≤2.0 )-15 10×| < 3.0 (y |≤2.5

[GeV]jjm310 410

[pb/

GeV

]y*

d jjm

/dσ2 d

21−10

18−10

15−10

12−10

9−10

6−10

3−10

1

310

610

910

1210

201706241336

ATLAS-1fb3.2 --1nb81 = 13 TeV, s

=0.4R tanti-k

uncertaintiesSystematic

EW corr.×Non-pert. corr. ×NLOJET++ (CT14 PDF)

)0 10×y* < 0.5 ()-3 10× y* < 1.0 (≤0.5 )-6 10× y* < 1.5 (≤1.0

)-9 10× y* < 2.0 (≤1.5 )-12 10× y* < 2.5 (≤2.0 )-15 10× y* < 3.0 (≤2.5



Ratios of inclusive cross sections to NLO pQCD predictions with different PDFs

[GeV]T

p

210 210×2 310 310×2

0.80.9

11.11.2 1.5<y||≤1.0

[GeV]T

p210 210×2 310 310×2

0.80.9

11.11.2 1.0<y||≤0.5

[GeV]T

p210 210×2 310 310×2

The

ory/

Dat

a

0.60.8

11.21.41.6 0.5<|y|

[GeV]T

p

210 210×2 310 310×2

0.51

1.52

2.53.0<y||≤2.5

[GeV]T

p210 210×2 310 310×2

0.60.8

11.21.41.6 2.5<y||≤2.0

[GeV]T

p210 210×2 310 310×2

The

ory/

Dat

a

0.60.8

11.21.4 2.0<y||≤1.5 ATLAS

-1fb3.2 --1nb81=L

= 13 TeVs

=0.4R tanti-k

Data

NLO QCD

NP k⊗ EW k⊗maxT

p = F

µ = R

µ

CT14

HERAPDF 2.0

ABMP16

MMHT 2014, and NNPDF 3.0 show very similar behaviour to CT14.



Ratios of dijet cross sections to NLO pQCD predictions with different PDFs

[GeV]jjm

210×3 310 310×2 410

0.6

0.81

1.2

1.4 1.5 y*<≤1.0 [GeV]jjm

210×3 310 310×2 410

0.6

0.8

1

1.2

1.4 1.0 y*<≤0.5 [GeV]jjm

210×3 310 310×2 410

The

ory/

Dat

a

0.6

0.81

1.2

1.4 0.5y*<

[GeV]jjm

210×7 310 310×2 4100.5

1

1.5

2 3.0 y*<≤2.5 [GeV]jjm

210×7 310 310×2 410

0.81

1.2

1.4

1.6 2.5 y*<≤2.0 [GeV]jjm

210×7 310 310×2 410

The

ory/

Dat

a

0.6

0.8

1

1.2

1.4 2.0 y*<≤1.5 ATLAS-1fb3.2 --1nb81=L

= 13 TeVs

=0.4R tanti-k

Data

NLO QCD

NP k⊗ EW k⊗

exp(0.3y*)T

p = µ

CT14

HERAPDF 2.0

ABMP16

MMHT 2014, and NNPDF 3.0 show very similar behaviour to CT14.



Ratios of inclusive cross sections to NLO and NNLO predictions (µ = pjetT )

[GeV]T

p

210 210×2 310 310×2

0.80.9

11.11.21.31.4 1.5<y||≤1.0

[GeV]T

p210 210×2 310 310×2

0.80.9

11.11.21.31.4 1.0<y||≤0.5

[GeV]T

p210 210×2 310 310×2

The

ory/

Dat

a

0.60.8

11.21.4 0.5<|y|

[GeV]T

p

210 210×2 310 310×2

0.5

1

1.5

2

2.5 3.0<y||≤2.5 [GeV]

Tp

210 210×2 310 310×2

0.60.8

11.21.41.6 2.5<y||≤2.0

[GeV]T

p210 210×2 310 310×2

The

ory/

Dat

a

0.60.8

11.21.4 2.0<y||≤1.5 ATLAS

-1fb3.2 --1nb81=L

= 13 TeVs

=0.4R tanti-k

Data

NLO QCD

NP k⊗ EW k⊗

NNLO QCD

NP k⊗ EW k⊗jet

Tp =

Fµ =

Rµ

NLOMMHT 2014 NLO

NNLOMMHT 2014 NNLO



Ratios of inclusive cross sections to NLO and NNLO predictions (µ = pmaxT )

[GeV]T

p

210 210×2 310 310×2

0.80.9

11.11.21.31.4 1.5<y||≤1.0

[GeV]T

p210 210×2 310 310×2

0.80.9

11.11.21.31.4 1.0<y||≤0.5

[GeV]T

p210 210×2 310 310×2

The

ory/

Dat

a

0.60.8

11.21.4 0.5<|y|

[GeV]T

p

210 210×2 310 310×2

0.5

1

1.5

2

2.5 3.0<y||≤2.5 [GeV]

Tp

210 210×2 310 310×2

0.60.8

11.21.41.6 2.5<y||≤2.0

[GeV]T

p210 210×2 310 310×2

The

ory/

Dat

a

0.60.8

11.21.4 2.0<y||≤1.5 ATLAS

-1fb3.2 --1nb81=L

= 13 TeVs

=0.4R tanti-k

Data

NLO QCD

NP k⊗ EW k⊗

NNLO QCD

NP k⊗ EW k⊗maxT

p = F

µ = R

µ

NLOMMHT 2014 NLO

NNLOMMHT 2014 NNLO


CMS cross sections at√s = 13 TeV [Eur. Phys. J. C 76 (2016) 451]

Inclusive jet cross sections for anti-kt jets (R = 0.4, R = 0.7).

Comparison with NLO pQCD predictions and fixed order + parton shower.

Kinematic phase space: 114 GeV < pT < 2 TeV; |y | < 4.7

(GeV)T

Jet p200 300 1000 2000

dy

(pb/

GeV

)T

/ dp

σ2 d

-310

-110

10

310

510

710

910

1110

1310

1510)6|y| < 0.5 (x10

)50.5 < |y| < 1.0 (x10)41.0 < |y| < 1.5 (x10)31.5 < |y| < 2.0 (x10)22.0 < |y| < 2.5 (x10)12.5 < |y| < 3.0 (x10)03.2 < |y| < 4.7 (x10

NLOJet++ CT14

(13 TeV)-1< 71 pb

R = 0.4t

Anti-k

CMS

(GeV)T

Jet p200 300 1000 2000

dy

(pb/

GeV

)T

/ dp

σ2 d

-310

-110

10

310

510

710

910

1110

1310

1510)6|y| < 0.5 (x10

)50.5 < |y| < 1.0 (x10)41.0 < |y| < 1.5 (x10)31.5 < |y| < 2.0 (x10)22.0 < |y| < 2.5 (x10)12.5 < |y| < 3.0 (x10)03.2 < |y| < 4.7 (x10

PH+P8 CUETM1

(13 TeV)-1< 71 pb

R = 0.7t

Anti-k

CMS



Ratios of the cross sections to NLO predictions for R = 0.4 and R = 0.7 forthe most central (left) and most forward (right) rapidity bins

(GeV)T

Jet p200 300 400 1000 2000

Rat

io to

NLO

Jet+

+ C

T14

0.5

1

1.5

2

2.5DataHERAPDF1.5NNPDF3.0MMHT2014Exp. uncert.Theo. uncert.

(13 TeV)-171 pb

CMS

R = 0.4tAnti-k|y| < 0.5

(GeV)T

Jet p120 140 160 180 200 220

Rat

io to

NLO

Jet+

+ C

T14

0.5

1

1.5

2

2.5

3 DataHERAPDF1.5NNPDF3.0MMHT2014Exp. uncert.Theo. uncert.

(13 TeV)-144 pb

CMS

R = 0.4tAnti-k3.2 < |y| < 4.7

(GeV)T

Jet p200 300 400 1000 2000

Rat

io to

NLO

Jet+

+ C

T14

0.5

1

1.5

2

2.5DataHERAPDF1.5NNPDF3.0MMHT2014Exp. uncert.Theo. uncert.

(13 TeV)-171 pb

CMS

R = 0.7tAnti-k|y| < 0.5

(GeV)T

Jet p120 140 160 180 200 220

Rat

io to

NLO

Jet+

+ C

T14

0.5

1

1.5

2

2.5

3 DataHERAPDF1.5NNPDF3.0MMHT2014Exp. uncert.Theo. uncert.

(13 TeV)-144 pb

CMS

R = 0.7tAnti-k3.2 < |y| < 4.7

Reasonable description within experimental and theoretical uncertainties.



Ratios of the cross sections to fixed order + parton shower MC for R = 0.4 andR = 0.7 for the most central (left) and most forward (right) rapidity bins

(GeV)T

Jet p200 300 1000 2000

Rat

io to

PH

+P8

CU

ETM

1

0.5

1

1.5

2

2.5DataPH+P8 CUETS1-CTEQ6L1PH+P8 CUETS1-HERAPDFP8 CUETM1Hpp CUETS1Exp. uncert.

(13 TeV)-171 pb

CMS

R = 0.4tAnti-k|y| < 0.5

(GeV)T

Jet p120 140 160 180 200 220

Rat

io to

PH

+P8

CU

ETM

1

0.5

1

1.5

2

2.5

3DataPH+P8 CUETS1-CTEQ6L1PH+P8 CUETS1-HERAPDFP8 CUETM1Hpp CUETS1Exp. uncert.

(13 TeV)-144 pb

CMS

R = 0.4tAnti-k3.2 < |y| < 4.7

(GeV)T

Jet p200 300 1000 2000

Rat

io to

PH

+P8

CU

ETM

1

0.5

1

1.5

2

2.5DataPH+P8 CUETS1-CTEQ6L1PH+P8 CUETS1-HERAPDFP8 CUETM1Hpp CUETS1Exp. uncert.

(13 TeV)-171 pb

CMS

R = 0.7tAnti-k|y| < 0.5

(GeV)T

Jet p120 140 160 180 200 220

Rat

io to

PH

+P8

CU

ETM

1

0.5

1

1.5

2

2.5

3DataPH+P8 CUETS1-CTEQ6L1PH+P8 CUETS1-HERAPDFP8 CUETM1Hpp CUETS1Exp. uncert.

(13 TeV)-144 pb

CMS

R = 0.7tAnti-k3.2 < |y| < 4.7

Herwig++ and Pythia 8 (LO+PS) deviate from the data for central rapidities.


Summary of αs determinations

Comparison of values of αs(Q2) from several measurements at different scales

Q [GeV]

210 310

(Q

)s

α

0.08

0.09

0.1

0.11

0.12

0.13

0.14 ATEEC 2012 Global fit World Average 2016

ATEEC 2012 ATEEC 2011

32CMS R CMS 3jet mass

CMS inclusive jets cross sectiontCMS t

D0 angular correlations D0 inclusive jets

ATLAS


Summary of αs determinations

Comparison of values of αs(Q2) from several measurements at different scales

Q (GeV)5 6 7 8 10 20 30 40 100 200 300 1000 2000

(Q)

Sα

0.08

0.1

0.12

0.14

0.16

0.18

0.2

0.22

0.24 -0.0043+0.0060) = 0.1164z(MSα = 8TeV, sCMS Incl.Jet,

= 8TeVsCMS Incl.Jet, = 7TeVs , 32CMS R

= 7TeVsCMS Incl.Jet , = 7TeVs , tCMS t

= 7TeVsCMS 3-Jet Mass , D0 Incl.JetD0 Angular CorrelationH1ZEUS

0.0011±) = 0.1181 z(MSαWorld Avg

CMS


Summary and conclusions

Jet cross sections and event shapes have been measured in severalconditions

ATLAS and CMS presented cross-section measurements at centre-of-massenergies of

√s = 8 and 13 TeV.

CMS presented an additional triple-differential measurement

ATLAS presented an additional determination of αs using TEEC.

CMS has determined both PDFs and αs from their jet cross sections(double and triple differential) at 8 TeV.


jet measurements at the lhc and impact on s and pdfs · jet measurements at the lhc and impact on s...

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