Post on 24-Apr-2020
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 2 / 25
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 3 / 25
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 4 / 25
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 5 / 25
ATLAS determination of αs from TEEC [Eur. Phys. J. 77 (2017) 872]
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 .
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 6 / 25
ATLAS determination of αs from TEEC [Eur. Phys. J. 77 (2017) 872]
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.)
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 7 / 25
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 (
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 8 / 25
CMS inclusive jet cross sections at√s = 8 TeV [JHEP 03 (2017) 156]
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 9 / 25
CMS inclusive jet cross sections at√s = 8 TeV [JHEP 03 (2017) 156]
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.)
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 10 / 25
CMS inclusive jet cross sections at√s = 8 TeV [JHEP 03 (2017) 156]
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 11 / 25
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∗)
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 12 / 25
CMS triple-differential at√s = 8 TeV [Eur. Phys. J. C 77 (2017) 746]
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
CMS19.7 fb 1 (8 TeV)
DataExperimental uncertaintyTheoretical uncertaintyCT14 NLO EW NPMMHT 2014 NLO EW NPABM11 NLO EW NP
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
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
1 yb < 20 y* < 1
CMS19.7 fb 1 (8 TeV)
DataExperimental uncertaintyTheoretical uncertaintyCT14 NLO EW NPMMHT 2014 NLO EW NPABM11 NLO EW NP
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
CMS19.7 fb 1 (8 TeV)
DataExperimental uncertaintyTheoretical uncertaintyCT14 NLO EW NPMMHT 2014 NLO EW NPABM11 NLO EW NP
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
CMS19.7 fb 1 (8 TeV)
DataExperimental uncertaintyTheoretical uncertaintyCT14 NLO EW NPMMHT 2014 NLO EW NPABM11 NLO EW NP
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
CMS triple-differential at√s = 8 TeV [Eur. Phys. J. C 77 (2017) 746]
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.)
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 14 / 25
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 15 / 25
ATLAS cross sections at√s = 13 TeV [arXiv:1711.02692 (hep-ex)]
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 16 / 25
ATLAS cross sections at√s = 13 TeV [arXiv:1711.02692 (hep-ex)]
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 17 / 25
ATLAS cross sections at√s = 13 TeV [arXiv:1711.02692 (hep-ex)]
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 18 / 25
ATLAS cross sections at√s = 13 TeV [arXiv:1711.02692 (hep-ex)]
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 19 / 25
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 20 / 25
CMS cross sections at√s = 13 TeV [Eur. Phys. J. C 76 (2016) 451]
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 21 / 25
CMS cross sections at√s = 13 TeV [Eur. Phys. J. C 76 (2016) 451]
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 22 / 25
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 23 / 25
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
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 24 / 25
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.
Javier Llorente SM@LHC 2018 - Jets, αs and PDFs 25 / 25