γλώσσες
Σελίδες
Νομικός
Measurements of the proton structure at HERA
Ian C. Brock on behalf of the H1 and ZEUS collaborationsUniversity of Bonn!Blois 2014
Outline
• Introduction
• Recent FL measurements
• ZEUS and H1 NC/CC combinations
• HERAPDF 2.0
• F2b and F2c
• Summary
2
Many interesting and recent measurements not discussed due to lack of time: 22 papers in ZEUS/H1 combination!
HERA
• e± p collisions at √s = 318 GeV
• ∼0.5 fb-1 per experiment
• HERA 1:
• 1996 - 2000
• HERA 2 (longitudinal e± polarisation)
• 2004 - 2007
3
p 920 GeV
e±
27.5 GeV θ w.r.t. p beam η = -ln tan θ/2
DIS events and kinematics
• Characterise events:
• Q2
• Bjorken x, (0 < x < 1)
• Inelasticity y, (0 < y < 1)
4
!
!
!
!"#$%&'()*+,
%&'()*+,
%&'()*+,
-./*(0')
1*+)+,*'2)1*+)+,*'2)
-./*(0')
NC - scattered e
Q2 = s x yDIS ⇒ scattered e in detector
Q2 ≿1 GeV2
CC - scattered ν
Basic equations
• e±p cross-section and structure functions
• (Unpolarised) reduced cross-sections often used:
5
d2�(e±p)
dx dQ2=
2⇡↵2
xQ
4
⇥Y+F2(x,Q
2)⌥ Y�xF3(x,Q2)� y
2FL(x,Q
2)⇤
Y± = 1± (1� y)2
�r(or �) =d
2�
dx dQ
2· xQ
4
2⇡↵
2Y+
= F2(x,Q2)� y
2
Y+FL(x,Q
2)
Kinematic regions
6
Parameterise structure functions as a function of x Use DGLAP equations to evolve from HERA to LHC
Evolution depends on order: LO, NLO, NNLO
LHCTevatronHERA
Fixed target
FL
• FL proportional to cross-section of long. polarised photons
• 0 at lowest order!
• FL term in cross-section multiplied by y2
• Go to high y
• Make use of Q2 = s x y
• For given Q2 and x, vary s(y) to decouple F2 and FL
• HERA ran with Ep = 460 and 575 GeV in 2007 in order to vary s
7
� = F2(x,Q2)� y
2
Y+FL(x,Q
2)
FL
• ZEUS: include high-precision HERA 1 data (with shifted vertex to improve low Q2 measurement)
• H1: reanalyse and extend to lowest possible E′e
8
DESY-14-053, arXiv:1404.6376
DESY-13-211, EPJ. C 74 (2014) 2814
1 10 210 310
-0.2
0
0.2
0.4
4 1
0u
x 0.28
0.43
0.59
0.88
1.29
1.69
2.24
3.19
4.02
5.40
6.87
9.58
12.1
15.7
24.3
30.3
40.2
54.1
73.6
98.6
184
H1 and ZEUSLF
]2 [GeV2Q
HERAPDF1.5 NNLO
CT10 NNLO
MSTW08 NNLO
ABM12 NNLO
NNPDF2.3 NNLO
JR09 NNLO
H1ZEUSH1ZEUSH1ZEUS
1 10 210 310
-0.2
0
0.2
0.4 Reasonable precision ∼10% per point
Limited int. lumi.: 11.8 pb-1 at √s = 225 GeV 5.4 pb-1 at √s = 252 GeV
Combined cross-sections
• Complete set of H1 and ZEUS NC and CC measurements
• HERA 1 and HERA 2 datacombined
• Also includes latest FL andhigh x measurements
• 1307 data points!
• Correlated syst. uncertaintiesproperly taken into account
9H1prelim-14-041, ZEUS-prel-14-005
Good 𝜒2: 1685/1620 d.o.f.
Combined cross-sections
10
H1 and ZEUS preliminary
0
0.2
0.4
0.6
0.8
1
1.2
103
104
Q2/GeV2
mr,
NC
(x,Q
2 )
|
HERA NC e-p (prel.) 0.4 fb-1
3s = 318 GeVZEUS HERA IIZEUS HERA IH1 HERA IIH1 HERA I
x=0.008
x=0.032
x=0.08
x=0.25
H1 and ZEUS preliminary
0
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Q2/GeV2
mr,
NC
(x,Q
2 )
+
HERA NC e+p (prel.) 0.5 fb-1
3s = 318 GeVZEUS HERA IIZEUS HERA IH1 HERA IIH1 HERA I
x=0.0002
x=0.002
x=0.008
x=0.032
x=0.08
x=0.25
x=0.008 x=0.08
H1prelim-14-041, ZEUS-prel-14-005
Electroweak effects
11H1prelim-14-041, ZEUS-prel-14-005
H1 and ZEUS preliminary
0
0.2
0.4
0.6
0.8
1
1.2
103
104
105
Q2/GeV2
mr,
NC
(x,Q
2 )
3s = 318 GeV
HERA NC e+p (prel.) 0.5 fb-1
HERA NC e- p (prel.) 0.4 fb-1
x=0.008
x=0.032
x=0.08
x=0.25]2
[pb/
GeV
2/d
Qmd
-710
-510
-310
-110
10
]2 [GeV2Q310 410
p CC±H1 ep CC+H1 e
p CC HERA II±ZEUS ep CC HERA II+ZEUS e
p CC (HERAPDF 1.5)±SM ep CC (HERAPDF 1.5)+SM e
p NC±H1 ep NC+H1 e
p NC HERA II±ZEUS ep NC HERA II+ZEUS e
p NC (HERAPDF 1.5)±SM ep NC (HERAPDF 1.5)+SM e
y < 0.9 = 0eP
HERA
HERAPDF 2.0
• Use ZEUS + H1 combined cross-sections (only) to extract PDFs:
• Low Q2 data constrain sea and gluon
• High Q2 NC and CC data constrain valence quarks
• Main tool used is HERAFitter (see next talk)
• Up-to-date theory treatment (especially of heavy flavour) included
• NLO + NNLO PDFs determined12
HERAPDF 2.0 (NC data)
13
0
0.5
1
1.5
0
0.5
1
1.5
0
0.5
1
1.5
H1 and ZEUS preliminaryQ2 = 3.5 GeV2
mr,
NC
(x,Q
2 )
+
Q2 = 5 GeV2 Q2 = 6.5 GeV2 Q2 = 8.5 GeV2
Q2 = 12 GeV2 Q2 = 15 GeV2 Q2 = 20 GeV2 Q2 = 25 GeV2
Q2 = 35 GeV2 Q2 = 45 GeV2
10-3 10-1
Q2 = 60 GeV2
10-3 10-1
Q2 = 90 GeV2
10-3 10-1
xQ2 = 120 GeV2
10-3 10-1
x
HERA NC e+p (prel.) 26 pb-1
3s = 225 GeVHERAPDF2.0 (prel.)NNLO, Q2 = 3.5 GeV2NNLO, Qmin0
0.5
1
1.5
0
0.5
1
1.5
0
0.5
1
1.5
0
0.5
1
1.5
H1 and ZEUS preliminaryQ2 = 3.5 GeV2
mr,
NC
(x,Q
2 )
+
Q2 = 5 GeV2 Q2 = 6.5 GeV2 Q2 = 8.5 GeV2
Q2 = 12 GeV2 Q2 = 15 GeV2 Q2 = 20 GeV2 Q2 = 25 GeV2
Q2 = 35 GeV2 Q2 = 45 GeV2
10-3 10-1
Q2 = 60 GeV2
10-3 10-1
Q2 = 90 GeV2
10-3 10-1
xQ2 = 120 GeV2
10-3 10-1
x
HERA NC e+p (prel.) 13 pb-1
3s = 251 GeVHERAPDF2.0 (prel.)NLO, Q2 = 3.5 GeV2NLO, Qmin0
0.5
1
1.5
0
1
0
1
0
1
0
1
0
1
H1 and ZEUS preliminaryQ2 = 2 GeV2
mr,
NC
(x,Q
2 )
+
Q2 = 2.7 GeV2 Q2 = 3.5 GeV2 Q2 = 4.5 GeV2
Q2 = 6.5 GeV2 Q2 = 8.5 GeV2 Q2 = 10 GeV2 Q2 = 12 GeV2
Q2 = 15 GeV2 Q2 = 18 GeV2 Q2 = 22 GeV2 Q2 = 27 GeV2
Q2 = 35 GeV2 Q2 = 45 GeV2
10-3 10-1
Q2 = 60 GeV2
10-3 10-1
Q2 = 70 GeV2
xQ2 = 90 GeV2
10-3 10-1
Q2 = 120 GeV2
10-3 10-1
x
HERA NC e+p (prel.) 0.5 fb-1
3s = 318 GeVHERAPDF2.0 (prel.)NLO, Q2 = 3.5 GeV2NLO, Qmin
0
0.5
1
1.5
0
0.5
1
1.5
10 -2 10 -1
0
0.5
1
1.5
10 -2 10 -1
H1 and ZEUS preliminary
Q2 = 150 GeV2
mr,
NC
(x,Q
2 )
+
Q2 = 200 GeV2 Q2 = 250 GeV2
Q2 = 300 GeV2 Q2 = 400 GeV2 Q2 = 500 GeV2
xQ2 = 650 GeV2 Q2 = 800 GeV2
x
HERA NC e+p (prel.) 26 pb-1
3s = 225 GeVHERAPDF2.0 (prel.)NLO, Q2 = 3.5 GeV2NLO, Qmin
10 -2 10 -1
0
0.5
1
1.5
0
0.5
1
1.5
10 -2 10 -1
0
0.5
1
1.5
10 -2 10 -1
H1 and ZEUS preliminary
Q2 = 150 GeV2
mr,
NC
(x,Q
2 )
+
Q2 = 200 GeV2 Q2 = 250 GeV2
Q2 = 300 GeV2 Q2 = 400 GeV2 Q2 = 500 GeV2
xQ2 = 650 GeV2 Q2 = 800 GeV2
x
HERA NC e+p (prel.) 13 pb-1
3s = 251 GeVHERAPDF2.0 (prel.)NLO, Q2 = 3.5 GeV2NLO, Qmin
10 -2 10 -1
0
1
2
0
1
0
1
0
0.5
0
0.2
H1 and ZEUS preliminaryQ2 = 150 GeV2
mr,
NC
(x,Q
2 )
+
Q2 = 200 GeV2 Q2 = 250 GeV2 Q2 = 300 GeV2
Q2 = 400 GeV2 Q2 = 500 GeV2 Q2 = 650 GeV2 Q2 = 800 GeV2
Q2 = 1000 GeV2 Q2 = 1200 GeV2 Q2 = 1500 GeV2 Q2 = 2000 GeV2
Q2 = 3000 GeV2 Q2 = 5000 GeV2 Q2 = 8000 GeV2
10-2 10-1
Q2 = 12000 GeV2
10-2 10-1
xQ2 = 20000 GeV2
10-2 10-1
Q2 = 30000 GeV2
10-2 10-1
x
HERA NC e+p (prel.) 0.5 fb-1
3s = 318 GeVHERAPDF2.0 (prel.)NLO, Q2 = 3.5 GeV2NLO, Qmin
Low Q2
High Q2
√s = 225 GeV √s = 251 GeV √s = 318 GeV
H1 and ZEUS preliminary
1.14
1.16
1.18
1.2
1.22
1.24
0 5 10 15 20 25 30
Q2 cut / GeV2
χ2 /dof
HERAPDF2.0 (prel.)NLONNLO
χ2/dof = 1386/1130
χ2/dof = 1156/1001
Figure 24: The χ2 per degree of freedom vs the minimum Q2 of data entering the QCD fit forthe NLO and NNLO fits.
30
H1prelim-14-042, ZEUS-prel-14-007
HERAPDF 2.0 NNLO (2 of many plots!)
14
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
exp. uncert.
model uncert. parametrization uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
exp. uncert.
model uncert. parametrization uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
Figure 30: The parton distribution functions from HERAPDF2.0(prel.) at NNLO,xuv, xdv, xS = 2x(U + D), xg, at Q2 = 10 GeV2, for the Q2min = 3.5 GeV2 fit (top) and theQ2min = 10 GeV2 fit (bottom) The gluon and sea distributions are scaled down by a factor 20.The experimental, model and parametrisation uncertainties are shown separately.
36
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
exp. uncert.
model uncert. parametrization uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
exp. uncert.
model uncert. parametrization uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
Figure 30: The parton distribution functions from HERAPDF2.0(prel.) at NNLO,xuv, xdv, xS = 2x(U + D), xg, at Q2 = 10 GeV2, for the Q2min = 3.5 GeV2 fit (top) and theQ2min = 10 GeV2 fit (bottom) The gluon and sea distributions are scaled down by a factor 20.The experimental, model and parametrisation uncertainties are shown separately.
36
H1prelim-14-042, ZEUS-prel-14-007
Q2min = 3.5 GeV2 Q2min = 10 GeV2
HERAPDF 2.0
• Preliminary version released (NLO + NNLO); LO to come
• Still studying:
• Start from 3.5 or 10 GeV2 for default fit
• Gluon parametrisation?
• Number of free parameters?
• Heavy flavour scheme: RTOPT or ACOT
15
F2b and F2c
• ZEUS has finalised inclusive measurement of F2b and F2c
• Uses secondary vertex decay-length significance and jet mass to separate b, c, and light flavour
16
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
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510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
10
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
10
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
310
410
510
610
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
310
410
510
610
ZEUS < 1.4 GeVvtx1 < m < 2 GeVvtx1.4 < m
< 6 GeVvtx2 < m vtxNo restriction on m
-1ZEUS 354 pb
Monte Carlo
LF
CharmBeauty
|S|4 6 8 10 12 14 16 18 20
En
trie
s
210
310
410
|S|4 6 8 10 12 14 16 18 20
En
trie
s
210
310
410
|S|4 6 8 10 12 14 16 18 20
En
trie
s
210
310
410
|S|4 6 8 10 12 14 16 18 20
En
trie
s
210
310
410
|S|4 6 8 10 12 14 16 18 20
En
trie
s
210
310
410
|S|4 6 8 10 12 14 16 18 20
En
trie
s
210
310
410
|S|4 6 8 10 12 14 16 18 20
En
trie
s
310
410
510
|S|4 6 8 10 12 14 16 18 20
En
trie
s
310
410
510
ZEUS < 1.4 GeVvtx1 < m < 2 GeVvtx1.4 < m
< 6 GeVvtx2 < m vtxNo restriction on m
-1ZEUS 354 pb
Monte Carlo
LF
Charm
Beauty
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
210
310
410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
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310
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510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
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310
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510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
10
210
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410
510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
10
210
310
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510
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
310
410
510
610
S-20 -15 -10 -5 0 5 10 15 20
En
trie
s
310
410
510
610
ZEUS < 1.4 GeVvtx1 < m < 2 GeVvtx1.4 < m
< 6 GeVvtx2 < m vtxNo restriction on m
-1ZEUS 354 pb
Monte Carlo
LF
CharmBeauty
DESY-14-083, arXiv:1405.XXXX
Reduced cross-sections & F2b / F2c
17
0
0.2
0.4
0.6
0
0.2
0.4
0.6
0
0.2
0.4
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0
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0
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0
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0.6
0
0.2
0.4
0.6
x -410
-310 -210
x -410
-310 -210
x -410
-310 -210
cc r
σ
0
0.2
0.4
0.6
0
0.2
0.4
0.6
0
0.2
0.4
0.6
ZEUS2 = 7 GeV2Q 2 = 12 GeV2Q 2 = 18 GeV2Q
2 = 32 GeV2Q 2 = 60 GeV2Q 2 = 120 GeV2Q
2 = 650 GeV2Q
-1ZEUS vtx 354 pb-1ZEUS D* 363 pb-1 354 pb+ZEUS D
HERA
)2 (GeV2Q
10 2103
10
+ 0
.03 i
bb 2
F0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
0.22 -1ZEUS vtx 354 pb
-1ZEUS e 363 pb
-1 114 pbµZEUS
-1+vtx 126 pbµZEUS
-1H1 vtx 246 pb
HERAPDF 1.5
ABKM NNLO
MSTW08 NLO
MSTW08 NNLO
CTEQ6.6 NLO
JR09
x=0.032 i=0
x=0.013 i=1
x=0.005 i=2
x=0.002 i=3
x=0.0013 i=4
x=0.0005 i=5
x=0.0002 i=6
x=0.00013 i=7
BeautyCharm
Redu
ced
cros
s-se
ctio
n
Stru
ctur
e fu
nctio
n
DESY-14-083, arXiv:1405.XXXX
Beauty-quark mass
• Use σrb and HERA 1 cross-sections to extract mb
• Similar method already used for mc
18
) (GeV)b
(mbm3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 4.3 4.4 4.5
2χ
586
588
590
592
594
596
598
600ZEUS
Inclusive DIS + beauty QCD fit
[GeV]µ10 210
) [G
eV]
µ( bm
2
2.5
3
3.5
4
4.5
5ZEUS
PDG with evolved uncertaintyZEUSDELPHI 3-jetsDELPHI 4-jets NLOALEPHOPALSLD
mb(mb) = 4.07± 0.14 (fit)+0.01�0.07 (mod.)
+0.05�0.00 (param.)
+0.08�0.05 (theo.)GeV
DESY-14-083, arXiv:1405.083
Summary
• ZEUS and H1 NC cross-sections combined
• Much improved precision!
• Updated measurements of FL and cross-sections at high x
• HERAPDF 2.0 (prelim.) recently released
• NLO and NNLO PDFs available; publication in preparation
• ZEUS inclusive F2b and F2
c measurements finalised
• Most precise F2b over wide kinematic range
• Use σrb data to extract mb(mb) at hadron collider for 1st time
19
Backup
DIS events and kinematics
• Characterise events:
• Q2
• Bjorken x, (0 < x < 1)
• Inelasticity y, (0 < y < 1)
21
Q2 = s x y
Very high Q2 event
Kinematic regions
22
Before LHC With LHC
Use DGLAP equations to evolve from HERA to LHC
Typical NC event selection
• Electron or high ET trigger
• Scattered electron with E > 10 GeV
• Cut on Σ(E - pZ) ≈ 2Ee (calorimeter) for DIS events
• Cut on event vertex (tracker)
23
High-x cross-sections
• Extend analysis to x ≈ 1 by using electron ET or modified Jacquet-Blondel method to measure x
24DESY-13-245, arXiv:1312.4438
ZEUS
DA
TA/T
HEO
RY
1
1.2=7252Q =8752Q =10252Q
1
1.2 =12002Q =14002Q =16502Q
1
1.5=19502Q =22502Q =26002Q
1
2 =30002Q =35002Q
0 0.2 0.4 0.6 0.8 1
=41502Q
1
2=52502Q =70002Q 2 in GeV2Q
-1p, 185 pb-ZEUS e
(Integrated)-1p, 185 pb-ZEUS e
HERAPDF 1.5
0 0.2 0.4 0.6 0.8 1
2
4 =95002Q
0 0.2 0.4 0.6 0.8 1
=15500 2QABM11/HERAPDF 1.5
CT10/HERAPDF 1.5
MSTW 2008/HERAPDF 1.5
NNPDF 2.3/HERAPDF 1.5
x
ZEUS
DA
TA/T
HEO
RY
1
1.2=7252Q =8752Q =10252Q
0.8
1
1.2 =12002Q =14002Q =16502Q
0.5
1
=19502Q =22502Q =26002Q
1
2 =30002Q =35002Q
0 0.2 0.4 0.6 0.8 1
=41502Q
1
2=52502Q =70002Q
68% CI?, 2 in GeV2Q
-1p, 142 pb+ZEUS e
(Integrated)-1p, 142 pb+ZEUS e
HERAPDF 1.5
0 0.2 0.4 0.6 0.8 1
1
2
3=95002Q
0 0.2 0.4 0.6 0.8 1
=15500 2QABM11/HERAPDF 1.5
CT10/HERAPDF 1.5
MSTW 2008/HERAPDF 1.5
NNPDF 2.3/HERAPDF 1.5
x
GMVFNS schemes: RTOPT and ACOT etc.
25
HERAPDF PDF parametrisations
26
Comparison of PDFs
27
HERAPDF 2.0
28
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NLO Q
exp. uncert. model uncert. parametrisation uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
exp. uncert. model uncert. parametrisation uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
NLO NNLOQ2min = 3.5 GeV2
HERAPDF 2.0
29
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NLO Q
exp. uncert. model uncert. parametrisation uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
exp. uncert. model uncert. parametrisation uncert.
x
xf 2 = 10 GeV2fµ
vxu
vxd
0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
NLO NNLOQ2min = 10 GeV2
HERAPDF 2.0 (linear x scale)
30
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NLO Q
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NLO Q
x
xf 2 = 10 GeV2fµ
vxu
vxd
xS
xg
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
x
xf 2 = 10 GeV2fµ
vxu
vxd
xS
xg
H1 and ZEUS preliminary
Vary Q2minNLO NNLO
HERAPDF 2.0 (log x scale)
31
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NLO Q
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NLO Q
x
xf 2 = 10 GeV2fµ
vxu
vxd 0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
2 = 10 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
x
xf 2 = 10 GeV2fµ
vxu
vxd 0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminaryNLO NNLO
Vary Q2min
HERAPDF 1.0 & 1.5 vs. 2.0 (linear x scale)
32
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NLO Q
HERAPDF1.0 NLO
x
xf 2 = 10 GeV2fµ
vxu
vxd
xS
xg
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
0 0.2 0.4 0.6 0.8 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
HERAPDF1.5 NNLO
x
xf 2 = 10 GeV2fµ
vxu
vxd
xS
xg
H1 and ZEUS preliminaryNLO NNLO
Q2min = 3.5 GeV2
HERAPDF 1.0 & 1.5 vs. 2.0 (log x scale)
33
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NLO Q
HERAPDF1.0 NLO
x
xf 2 = 10 GeV2fµ
vxu
vxd 0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminary
0.2
0.4
0.6
0.8
1
-410 -310 -210 -110 1
2 = 3.5 GeVmin2 HERAPDF2.0 (prel.) NNLO Q
HERAPDF1.5 NNLO
x
xf 2 = 10 GeV2fµ
vxu
vxd 0.05)×xS (
0.05)×xg (
H1 and ZEUS preliminaryNLO NNLO
Q2min = 3.5 GeV2
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