[PPT] - Precision PDFs at Future Colliders Claire Gwenlan, Oxford on behalf PowerPoint Presentation

SLIDE 1

Claire Gwenlan, Oxford

n behalf of the LHeC and FCC-eh WGs

QC QCD@LH LHC 2019 2019

Bu Buffalo, New Yo York

15 15 – 19 19 Jul uly 2019 2019

Precision PDFs at Future Colliders

SLIDE 2

2

utline
pdfs from future ep high energy colliders, LHeC and FCC-eh

summary of ongoing studies towards update of LHeC CDR (arXiV:1206.2913); FCC-eh pdf studies from FCC CDR, volume 1 (EPJ C79 (2019), no.6, 474),

plus some ongoing studies on a lower energy FCC configuration

pdfs from the HL-LHC

summary of Khalek et al., arXiv:1810.03639;

contribution to CERN yellow report on Standard Model Physics at the HL-LHC and HE-LHC, arXiv:1902.04070

SLIDE 3

x

6 −

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5 −

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4 −

10

3 −

10

2 −

10

1 −

10 1 Ratio 0.8 0.9 1 1.1 1.2 1.3 1.4

_s(M_Z)=0.118 α xg(x,Q), NNLO, Q^2=100 GeV^2,

CT14 MMHT2014 HERAPDF2.0 NNPDF3.1 ABMP16-118 Q = 1.00e+01 GeV

Generated with APFEL 2.7.1 Web [GeV]

X

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2

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Ratio

0.7 0.8 0.9 1 1.1 1.2 1.3 Gluon-Gluon, luminosity

CT14 ATLAS-epWZ16 MMHT2014 NNPDF3.1 ABMP16-118 = 1.40e+04 GeV S Generated with APFEL 2.7.1 Web

[GeV]

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Ratio

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 Gluon-Gluon, luminosity CT14 MMHT2014 NNPDF3.1 = 1.40e+04 GeV S

Generated with APFEL 2.7.1 Web

[GeV]

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Ratio

0.7 0.8 0.9 1 1.1 1.2 1.3 Gluon-Gluon, luminosity CT14 MMHT2014 NNPDF3.1 = 1.40e+04 GeV S

Generated with APFEL 2.7.1 Web

[GeV]

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Ratio

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 Quark-Antiquark, luminosity CT14 MMHT2014 NNPDF3.1 = 1.40e+04 GeV S

Generated with APFEL 2.7.1 Web

[GeV]

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Ratio

0.7 0.8 0.9 1 1.1 1.2 1.3 Quark-Antiquark, luminosity CT14 MMHT2014 NNPDF3.1 = 1.40e+04 GeV S

Generated with APFEL 2.7.1 Web

3

gg qqbar

H,t BSM W,Z,VH

pdfs poorly known at large and small x

higher precision needed also for H, W, t

pdf luminosities (LHC@14TeV)

current data above x=5.10-5, and below x=0.6–0.7

CT14 MMHT2014 HERAPDF2.0 NNPDF3.1 ABMP16-118 Q = 1.00e+01 GeV

xg(x,Q), NNLO, Q2=100 GeV2, αs(MZ)=0.118

Higgs production in gluon fusion c, b, low mass DY, soft QCD, MC tuning gluinos, KK gravitons, boosted top quarks, …

pdfs: the situation today

CT14 MMHT2014 NNPDF3.1 = 1.40e+04 GeV S CT14 MMHT2014 NNPDF3.1 = 1.40e+04 GeV S

SLIDE 4

4

improving knowledge: LHeC and FCC-eh

energy recovery LINAC e beam: up to 60 GeV Lint ⟶ 1 ab-1 (1000× HERA ; per 10 yrs)

perating synchronously :
with HL-LHC (or HE-LHC)

p: 7 (14) TeV, √s ≈ 1.3 (1.8) TeV

and/or later with an FCC (A)

p: 50 (20) TeV, √s ≈ 3.5 (2.2) TeV

e ERL ☨ FCC (A): a lower energy configuration that could operate earlier in an FCC tunnel, using current magnet technology

SLIDE 5

kinematic coverage

5

Max Klein Kobe 17.4.18

4-momentum transfer squared ↤EIC

pportunity for

unprecedented increase in DIS kinematic reach;

×1000 increase in lumi. no higher twist, no nuclear corrections, free of symmetry assumptions, N3LO theory possible, …

precision pdfs, and exploration of low x regime;

plus extensive physics program in its own right

⨉15/120 extension in Q2,1/x reach vs HERA

SLIDE 6

HL-LHC pdfs

6

arXiv:1810.03639

strange down ubar gluon BUT can’t we get precision pdfs from the LHC itself? HL-LHC

projections suggest it can go quite some way!

BUT projections are in an ideal world, where many different types of LHC measurements have well understood systematics, correlations, and no data inconsistencies

single, consistent DIS data set is a tried and tested reliable way to achieve precision

also, possible issues of timing …

SLIDE 7

timelines

7

50 fb-1 could be achieved in 3 years before LS5 and long before the end of HL-LHC running

− −

A final LHeC run in dedicated operat

− −1

F. Bordry, arXiv:1810.13022

circa 2030

LHeC projected Integrated Luminosity:

today LHeC 1st run, Lint approx. 50 fb-1

total Lint ⟶ 1 ab-1

end of HL-LHC

SLIDE 8

pdfs from ep colliders

8

Max Klein Kobe 17.4.18

⨉15/120 extension in Q2,1/x reach vs HERA

4-momentum transfer squared ↤EIC

Low Q Low Q2 NC NC

(γ exchange)

γ

e e

F2 ~ (q+qbar

bar) dF dF2/ 2/dlnQ dlnQ2 ~ αs·g q

Final States:

Final States:

(Jets, C Charm, …)

σ ~ αs⋅g

CC

CC

fl flavour composition

e+: d e : d e-: u : u

W±

e± ν d,u

6

High Q High Q2 NC NC e e

γ,Z

Z  P Parity Violation

xF xF3 ~ (q-qbar qbar)

valence

q
d,u

SLIDE 9

uncert. assumptions:
elec. scale: 0.1%;
hadr. scale 0.5%

radcor: 0.3%; 𝝳p at high y: 1% uncorrelated extra eff.: 0.5% CC syst: 1.5% luminosity: 0.5%

LHeC pdf programme

9

→ ubar, uv, dbar, dv, s, c, b, t, xg and αs QCD analysis a la HERAPDF, BUT no constraint that dbar=ubar at small x;

4+1 xuv, xdv, xUbar, xDbar and xg

completely resolve all proton pdfs, and αs to permille precision dataset e charge e pol. lumi (fb-1) NC/CC – –0.8 5,50,1000

luminosity

NC/CC + 1,10

positron

NC/CC – 50 NC/CC – +0.8 10,50 NEW LHeC simulations (e: 50 GeV, p: 7TeV)

polarisation

(important for EW physics)

NB, I will frequently refer to the following:

LHeC 1st Run (e-, 50 fb-1, P=-0.8) LHeC full inclusive (e-, 1000 fb-1, P=-0.8) + (e-, 50 fb-1, P=+0.8) + (e+,10 fb-1)

simulation and pdf fit studies:

M. Klein, CG

SLIDE 10

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

)

2

= 1.9 GeV

2

xg(x, Q

4

10

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2

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1

10 1 10

2

= 1.9 GeV

2

gluon distribution at Q

PDF (68% C.L.) CT14 NNPDF3.0 MMHT2014 HERAPDF2.0_EIG LHeC 50fb-1 e-, P=-0.8 LHeC full inclusive

10

gluon at large x

gluon at large x is small and currently very poorly known; crucial for new physics searches LHeC sensitivity at large x comes as part of overall package

high luminosity (×50–1000 HERA); fully constrained quark pdfs; small x; momentum sum rule

gluon and sea intimately related

LHeC can disentangle sea from valence quarks at large x, with precision measurements of CC and NC F2γZ, xF3γZ

LHeC

SLIDE 11

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.5 1 1.5 2

x

6

10

5

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2

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1

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Fractional uncertainty

0.85 0.9 0.95 1 1.05 1.1 1.15

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6

impact of luminosity on LHeC pdfs

11

sea quarks dv gluon uv

LHeC all inclusive

LHeC e-, P=-0.8 HERA

LHeC e-, P=-0.8 5 fb-1 50 fb-1 1000 fb-1

(1st Run)

large x (≡ large Q2), gain from increased Lint small and medium x quickly constrained (5 fb-1 ≡ ×5 HERA ≡ 1st year LHeC)

SLIDE 12

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.5 1 1.5 2

x

6

10

5

10

4

10

3

10

2

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1

10

Fractional uncertainty

0.85 0.9 0.95 1 1.05 1.1 1.15

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6

impact of positrons on LHeC pdfs

12

sea quarks dv gluon uv

LHeC all inclusive

LHeC e-, P=-0.8 HERA

LHeC 50fb-1 e-, P=-0.8 plus e+, P=0 1 fb-1 10 fb-1 50 fb-1

CC: e+ sensitive to d; NC: e± asymmetry gives xF3γZ, sensitive to valence

SLIDE 13

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.5 1 1.5 2

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.5 1 1.5 2

x

6

10

5

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1

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Fractional uncertainty

0.85 0.9 0.95 1 1.05 1.1 1.15

x

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1

10

Fractional uncertainty

0.85 0.9 0.95 1 1.05 1.1 1.15

collider configurations

13

sea quarks dv gluon uv

LHeC all inclusive

LHeC e-, P=-0.8 HERA

FCC-eh (A) FCC-eh

FCC-eh (A): new preliminary simulation with 2 ab-1 polarised e– (NB, NO e+ yet; impact especially in dv) FCC-eh: CDR, volume 1, EPJ C79 (2019), no.6, 474

FCC-eh (A) FCC-eh

p: 20 TeV p: 50 TeV

SLIDE 14

14

empowering LHC searches

gluons

SUSY (RPC, RPV), LQs, …

quarks

exotic and extra boson searches at high mass

external, reliable pdfs needed for range extension and interpretation

[GeV]

inv

m

1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

PDF w.r.t CT14nnlo [%] d

100

50
50

100 150 200 250

W (combined +/-)

NNPDF 3.0 (90% CL) NNPDF 3.0 (68% CL) MMHT14 (68% CL) ABM16 (68% CL) JR14 (68% CL) CT14 NNLO (90% CL) LHeC-13p LL (68% CL)

E. Kay & U. Klein using VRAP v0.9

W (combined +/-)

arXiv:1211.5102

SLIDE 15

x

7

10

6

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5

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3

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1

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Ratio to CT14

2
1

1 2 3 4 5 6 7

2

= 1.9 GeV

2

gluon distribution at Q

PDF (68% C.L.) CT14 NNPDF3.0 MMHT2014 HERAPDF2.0_EIG LHeC 50fb-1 e-, P=-0.8 LHeC full inclusive FCC-eh

x

7

10

6

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5

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3

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1

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Ratio to CT14

2
1

1 2 3 4 5 6 7

2

= 1.9 GeV

2

gluon distribution at Q

PDF (68% C.L.) CT14 NNPDF3.0 MMHT2014 HERAPDF2.0_EIG LHeC 50fb-1 e-, P=-0.8 LHeC full inclusive FCC-eh (p:20TeV) FCC-eh

gluon at small x

15

no current data much below x=5⨉10-5

LHeC provides single, precise and unambiguous dataset down to x=10-6 FCC-eh probes to even smaller x=10-7

explore low x QCD:

DGLAP vs BFKL; non-linear evolution; gluon saturation; implications for ultra high energy neutrino cross sections

LHeC FCC-eh

LHeC

FCC-eh

SLIDE 16

gluon at small x matters

16

recent evidence for onset of BFKL dynamics in HERA inclusive data

arXiv:1710.05935; confirmed in xFitter study, arXiv:1802.00064

impact for LHC and most certainly at ultra low x values probed at FCC

gg lumi xg(x)

effect of small x resummation

0.98 1 1.02 1.04 1.06 1.08 1.1 7 8 13 14 27 10 100 f.o. PDFs: NNPDF31sx_nnlo_as_0118 res PDFs: NNPDF31sx_nnlonllx_as_0118 band: PDF uncertainty mH = 125 GeV µF = µR = mH/2 ratio to N3LO √s [TeV] ggH production cross section --- effect of small-x resummation N3LO, f.o. PDFs N3LO, res PDFs N3LO+LLx, res PDFs √

effect of small x resummation on ggH cross section

impact on other EW observables could be as large

SLIDE 17

gluon at small x

17

ep simulated data very precise – significant constraining power to discriminate

between theoretical scenarios of small x dynamics F2 and FL predictions for simulated kinematics of LHeC and FCC-eh

measurement of FL has a critical role to play

arXiv:1710.05935

FL

F2

SLIDE 18

18

LHeC: enormously extended range and much improved precision c.f. HERA

LHeC F2cc (RAPGAP MC, 7 TeV x 100 GeV, 10 fb-1, εc=0.1)

x F2cc x 4i

Q2 = 2 GeV2,i=1 Q2 = 4 GeV2,i=2 Q2 = 12 GeV2,i=3 Q2 = 20 GeV2,i=4 Q2 = 60 GeV2,i=5 Q2 = 200 GeV2,i=6 Q2 = 400 GeV2,i=7 Q2 = 1000 GeV2,i=8 Q2 = 10000 GeV2,i=9 Q2 = 50000 GeV2,i=10

HERA combined data LHeC θc > 00 LHeC θc > 20 LHeC θc > 100

Q2 = 100000 GeV2,i=11

10

3

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LHeC F2bb (RAPGAP MC, 7 TeV x 100 GeV, 10 fb-1, εb=0.5)

x F2bb x 4i

Q2 = 2 GeV2,i=1 Q2 = 5 GeV2,i=2 Q2 = 12 GeV2,i=3 Q2 = 25 GeV2,i=4 Q2 = 60 GeV2,i=5 Q2 = 200 GeV2,i=6 Q2 = 650 GeV2,i=7 Q2 = 2000 GeV2,i=8 Q2 = 10000 GeV2,i=9 Q2 = 50000 GeV2,i=10

H1 vtx DATA LHeC θb > 00 LHeC θb > 20 LHeC θb > 100

Q2 = 100000 GeV2,i=11

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δMc = 50 (HERA) to 3 MeV: impacts on αs, regulates ratio of charm to light, crucial for precision t, H
δMb to 10 MeV; MSSM: Higgs produced dominantly via bb → A

c, b quarks

ε(c) assumed 10%, 1% light background, ~3% δ(syst)

SLIDE 19

19

strange

x=0.0001 x=0.00025 x=0.00035 x=0.0005 x=0.001 x=0.0025 x=0.0035 x=0.005 x=0.01 x=0.012 x=0.018 x=0.025 x=0.040 x=0.055 x=0.08

Q

2/GeV 2

anti-strange density [3

j]

εc=0.1, bgdq=0.01 LHeC e

p 60*7000 GeV

2 10 fb

1

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10 10

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Q

2/GeV 2

anti-strange density [3

j]

εc=0.1, bgdq=0.01 LHeC e

p 60*7000 GeV

2 10 fb

1

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LHeC: direct sensitivity to strange via W+s → c

(x,Q2) mapping of (anti) strange for first time

!!

ep&

s s c

–

G.R. Boroun, PLB 744 (2015) 142 G.R. Boroun, PLB 741 (2015) 197

also top PDF!

top quark becomes light at large Q2: new field of research

pens for top PDFs!

strange pdf poorly known;

suppressed cf. other light quarks? strange valence?

SLIDE 20

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6 H1_5+1 H1_5+1_HQs H1_5+1_HQ H1

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6 LHeC_5+1 full inclusive + HQs + HQscb LHeC_4+1 full inclusive

x

6

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Fractional uncertainty

0.75 0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 1.25 H1_5+1 H1_5+1_HQs H1_5+1_HQ H1

x

6

10

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Fractional uncertainty

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2

x

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2

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1

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Fractional uncertainty

0.7 0.8 0.9 1 1.1 1.2 1.3 H1_5+1 H1_5+1_HQs H1_5+1_HQ H1

x

6

10

5

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4

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Fractional uncertainty

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2

x

6

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5

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3

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2

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1

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Fractional uncertainty

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 H1_5+1 H1_5+1_HQs H1_5+1_HQ H1

x

6

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1

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Fractional uncertainty

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4

impact of HQ data on LHeC pdfs

20

strange gluon, small x gluon, large x more flexible parameterisation (5+1): xuv, xdv, xU, xd, xs and xg dbar

SLIDE 21

[GeV]

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Ratio

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

qq luminosity

[GeV]

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Ratio

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

qq luminosity

PDF4LHC15 LHeC 1st Run LHeC full inclusive gg luminosity

[GeV]

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Ratio

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2

gg luminosity

[GeV]

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Ratio

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2

gg luminosity

PDF4LHC15 LHeC 1st Run FCC-eh (A)

x

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1 xf(x,Q) 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 B1 PDFs

(x,Q) c x (x,Q) s x (x,Q) u x (x,Q) d x xg(x,Q) xd(x,Q) xu(x,Q) xs(x,Q) xc(x,Q) Q = 1.41e+00 GeV

Generated with APFEL 2.7.1 Web

21

summary of pdfs from ep

x

7 −

10

6 −

10

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10 1 xf(x,Q) 0.5 1 1.5 2 2.5 PDF4LHC NNLO MC PDFs

(x,Q) b x (x,Q) c x (x,Q) s x (x,Q) u x (x,Q) d x xg(x,Q) xd(x,Q) xu(x,Q) xs(x,Q) xc(x,Q) xb(x,Q) Q = 1.41e+00 GeV

Generated with APFEL 2.7.1 Web

LHeC 1st Run

50 fb-1 e–, P=-0.8

PDF4LHC15

√s = 14 TeV

gg luminosity qq luminosity

√s = 14 TeV

e– only

SLIDE 22

concentrate on datasets sensitive to mid-to-high-x; and not already systematics dominated

HL-LHC pdfs

22

study pdf constraints expected from LHC measurements by end

f HL-LHC phase

ATLAS+CMS 3 ab-1 LHCb 0.3 ab-1

(studies in arXiv:1810.03639; prepared for CERN

Yellow Report, arXiv:1902.04070)

Hessian profiling of PDF4LHC15

with tolerance T=3

systematic uncertainties taken from existing data;
treated as uncorrelated, with factor fcorr=0.5, chosen

to approximately reproduce effect of syst. correlations in existing measurements;

variable factor fred to estimate improvement to systs.

SLIDE 23

HL-LHC pdfs

23

arXiv:1810.03639

strange down ubar gluon scenario A: conservative scenario C: optimistic

(together with intermediate scenario B, all are available in lhapdf format)

1/0.5 (8/13)TeV 0.4/0.2 (8/13)TeV

SLIDE 24

parton luminosities

24

qq gq qqbar gg

arXiv:1810.03639

SLIDE 25

impact on LHC phenomenology

25

arXiv:1810.03639, and CERN yellow report, arXiv:1902.04070

dijets ggH

SLIDE 26

26

summary

precision determination of quark and gluon structure of proton and αs

f fundamental importance for future hadron collider physics programme (Higgs, BSM, …)

electron-proton colliders essential for full exploitation of hadron machines

external precision pdf input; complete q,g unfolding, high luminosity x ⟶ 1, s, c, b, (t); N3LO; small x; strong coupling to permille precision; …

NEW ep pdf studies presented (work in progress)

all critical pdf information can be obtained early with LHeC (~50 fb-1 ≡×50 HERA), in parallel with HL-LHC operation major new summary paper later this year; next workshop 24 – 25 Oct.

32

possibly 24-25 October 2019 … near CERN 24–25 October 2019 … at or near CERN

HL-LHC pdf studies indicate significant constraints;

complementarity between HL-LHC and LHeC (see also arXiv:1906.10127 )

caveats: ignored issues relating to correlation models; incompatible data sets; …

not all possible data sets included in either study (EG. LHeC jet data, for further constraints on gluon

at large x; HL-LHC data probing lower x; …)

SLIDE 27

extras

27

SLIDE 28

)'

':/9$;-<0*-'1"'OPKQKORST'

LHeC: √s= 1.3 TeV

×100–1000 HERA lumi.

ep colliders

HERA: world’s first and still

nly ep collider (√s ≃ 300 GeV)

LHeC: future ep (eA) collider,

proposed to run concurrently with HL/HE-LHC; CDR arXiV:1206.2913 (complementary to LHC; extra discovery

channels; Higgs; precision pdfs and 𝝱s)

FCC-eh: further future ep (eA)

collider, integrated with FCC;

CDR, volume 1, EPJ C79 (2019), no.6, 474

(further kinematic extension wrt LHeC)

EIC

28

“FCC-eh (A)”: √s= 2.2 TeV FCC-eh: √s= 3.5 TeV

SLIDE 29

strong coupling, αs

29

24.6 24.8 25 25.2 25.4 25.6 25.8 15 15.2 15.4 15.6 15.8 16 16.2 1/ log10(Q/GeV)

fine structure weak strong

αs: PDG LHeC 𝝱s is least known coupling constant

precise 𝝱s needed: to constrain GUT scenarios; for cross section predictions, including Higgs; …

LHeC: permille

precision possible in combined QCD fit for pdfs+𝝱s PDG2018: 𝝱s = 0.1174 ± 0.0016

(w/o lattice QCD, 1.5% uncertainty)

arXiv:1206.2913, 1211.5102, new studies underway

SLIDE 30

30

LHeC: NC+CC inclusive; total exp. uncertainties; independent of BCDMS

strong coupling 𝝱s

SLIDE 31

31

lattice QCD

ep: per mille level

(LHeC/FCC-eh combined

with HERA)

ee: order per mille

with an FCC-ee arXiv:1512.05194

SLIDE 32

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Ratio to CT14

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

2

= 1.9 GeV

2

up valence distribution at Q

PDF (68% C.L.) CT14 NNPDF3.0 MMHT2014 HERAPDF2.0_EIG LHeC 50fb-1 e-, P=-0.8 LHeC full inclusive

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Ratio to CT14

1
0.5

0.5 1 1.5 2 2.5 3

2

= 1.9 GeV

2

down valence distribution at Q

PDF (68% C.L.) CT14 NNPDF3.0 MMHT2014 HERAPDF2.0_EIG LHeC 50fb-1 e-, P=-0.8 LHeC full inclusive

32

valence quarks from LHeC

large x crucial for HL/HE–LHC and FCC searches; also relevant for DY, MW etc.;

resolve long-standing mystery of d/u ratio; …

u valence

precision determination; free from higher twist corrections and nuclear uncertainties

d valence LHeC

SLIDE 33

x

0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

2

= 10 GeV

2

dv/uv distribution at Q

CT14 NNPDF3.0 MMHT2014 ABM12 CJ15 (T=10) CJ15 (T=1.645) LHeC 50fb-1 e-, P = -0.8 LHeC full inclusive

V

0.9

(0) CQM (0.28) DSE1 (0.20) NJL, pQCD (0.18) DSE2 (1/2) SU(6)

33

d/u at large x

resolve long-standing mystery

f d/u ratio at large x

d/u essentially unknown at large x

no predictive power from current pdfs; conflicting theory pictures; data inconclusive, large nuclear uncerts.

SLIDE 34

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.5 1 1.5 2

x

6

10

5

10

4

10

3

10

2

10

1

10

Fractional uncertainty

0.85 0.9 0.95 1 1.05 1.1 1.15

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.9 0.92 0.94 0.96 0.98 1 1.02 1.04 1.06 1.08 1.1

x

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

Fractional uncertainty

0.4 0.6 0.8 1 1.2 1.4 1.6

impact of polarisation on LHeC pdfs

34

sea quarks dv gluon uv

LHeC all inclusive

LHeC e-, P=-0.8 HERA

(CC: σ(e±) scales as (1±P) ; NC: effects subtle; pol. asym. gives access to F2γZ, new quark combinations) impact of polarisation on pdfs generally small (but pol. important for ew)

LHeC 50+50 fb-1 e- P=-0.8,0 P=-0.8,+0.8 LHeC 50 fb-1 e- P=0 P=-0.8

SLIDE 35

35

LHeC studies: fit parameterisation

QCD fit ansatz based on HERAPDF2.0, with following differences

much more relaxed sea ie. no requirement that ubar=dbar at small x no negative gluon term (simply for the aesthetics of ratio plots – it has been checked that this does not impact size of projected uncertainties)

4+1 pdf fit (above) has 14 free parameters 5+1 pdf fit for HQ studies parameterises dbar and sbar separately, and has 17 free parameters

SLIDE 36

36

HL-LHC pdfs

SLIDE 37

37

arXiv:1810.03639

SLIDE 38

38

arXiv:1906.10127

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

g ( x, Q ) / ( g ( x, Q ) [ref] ) δ

PDF4LHC15 + LHeC (Tolerance = 1) + LHeC (Tolerance = 3) PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

d ( x, Q ) / ( d ( x, Q ) [ref] ) δ

PDF4LHC15 + LHeC (Tolerance = 1) + LHeC (Tolerance = 3) PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

( x, Q ) [ref] ) u ( x, Q ) / ( u δ

PDF4LHC15 + LHeC (Tolerance = 1) + LHeC (Tolerance = 3) PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

( x, Q ) [ref] )

+

( x, Q ) / ( s

+

s δ

PDF4LHC15 + LHeC (Tolerance = 1) + LHeC (Tolerance = 3) PDF errors, Q = 10 GeV

PDF4LHC15 profiled with (previous iteration of) LHeC inclusive+HQ simulated data

SLIDE 39

39

arXiv:1906.10127

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1 10

g ( x, Q ) / ( g ( x, Q ) [ref] ) δ PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

PDFs at the HL-LHC ( Q = 10 GeV )

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1 10

d ( x, Q ) / ( d ( x, Q ) [ref] ) δ PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

PDFs at the HL-LHC ( Q = 10 GeV )

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1 10

( x, Q ) [ref] ) u ( x, Q ) / ( u δ PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

PDFs at the HL-LHC ( Q = 10 GeV )

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1 10

( x, Q ) [ref] )

+

( x, Q ) / ( s

+

s δ PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

PDFs at the HL-LHC ( Q = 10 GeV )

PDF4LHC15 profiled with LHeC inclusive+HQ and HL-LHC simulated data

SLIDE 40

40

arXiv:1906.10127

PDF4LHC15 profiled with LHeC inclusive+HQ and HL-LHC simulated data

10

2

10

3

10 ( GeV )

X

M

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Gluon-Gluon Lumi (ratio to baseline)

PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

=14 TeV s Uncertanties in PDF luminosities @ 10

2

10

3

10 ( GeV )

X

M

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Quark-Gluon Lumi (ratio to baseline)

PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

=14 TeV s Uncertanties in PDF luminosities @ 10

2

10

3

10 ( GeV )

X

M

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Quark-Antiquark Lumi (ratio to baseline)

PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

=14 TeV s Uncertanties in PDF luminosities @ 10

2

10

3

10 ( GeV )

X

M

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Quark-Quark Lumi (ratio to baseline)

PDF4LHC15 + LHeC + HL-LHC + LHeC + HL-LHC

=14 TeV s Uncertanties in PDF luminosities @

SLIDE 41

41

arXiv:1906.10127

PDF4LHC15 and HERAPDF profiled with LHeC inclusive+HQ simulated data

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

g ( x, Q ) / ( g ( x, Q ) [ref] ) δ PDF4LHC15 HERAPDF (exp.) PDF4LHC + LHeC HERAPDF (exp.) + LHeC

PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

d ( x, Q ) / ( d ( x, Q ) [ref] ) δ PDF4LHC15 HERAPDF (exp.) PDF4LHC + LHeC HERAPDF (exp.) + LHeC

PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

( x, Q ) [ref] ) u ( x, Q ) / ( u δ PDF4LHC15 HERAPDF (exp.) PDF4LHC + LHeC HERAPDF (exp.) + LHeC

PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

( x, Q ) [ref] )

+

( x, Q ) / ( s

+

s δ PDF4LHC15 HERAPDF (exp.) PDF4LHC + LHeC HERAPDF (exp.) + LHeC

PDF errors, Q = 10 GeV

T=1

SLIDE 42

42

arXiv:1906.10127

PDF4LHC15 and HERAPDF profiled with LHeC inclusive+HQ simulated data

T=1

SLIDE 43

43

arXiv:1906.10127

PDF4LHC15 and HERAPDF (total uncerts) profiled with LHeC inclusive+HQ simulated data

T=1

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

g ( x, Q ) / ( g ( x, Q ) [ref] ) δ PDF4LHC15 HERAPDF (total) PDF4LHC + LHeC HERAPDF (total) + LHeC

PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

d ( x, Q ) / ( d ( x, Q ) [ref] ) δ PDF4LHC15 HERAPDF (total) PDF4LHC + LHeC HERAPDF (total) + LHeC

PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

( x, Q ) [ref] ) u ( x, Q ) / ( u δ PDF4LHC15 HERAPDF (total) PDF4LHC + LHeC HERAPDF (total) + LHeC

PDF errors, Q = 10 GeV

5 −

10

4 −

10

3 −

10

2 −

10

1 −

10

x

3 −

10

2 −

10

1 −

10 1

( x, Q ) [ref] )

+

( x, Q ) / ( s

+

s δ PDF4LHC15 HERAPDF (total) PDF4LHC + LHeC HERAPDF (total) + LHeC

PDF errors, Q = 10 GeV

SLIDE 44

impact on LHC phenomenology

44

arXiv:1810.03639, and CERN yellow report, arXiv:1902.04070

scenario C

dijets Higgs MW

SLIDE 45

x

10

10

9

10

8

10

7

10

6

10

5

10

4

10

3

10

2

10

1

10

( GeV )

X

M

1 10

2

10

3

10

4

10

5

10

Kinematics of a 100 TeV FCC

y=0 y=-4 y=-8 y=4 y=8

FCC 100 TeV LHC 14 TeV

Plot by J. Rojo, Dec 2013

Kinematics of a 100 TeV FCC

DY, low-pt jets W,Z Higgs, top 2 TeV squarks 20 TeV Z’

45

small x becomes relevant even for “common” physics (EG. W, Z, H, t) large x relevant in searches for new, very high mass states

SLIDE 46

impact of LHC on today’s pdfs

46

SLIDE 47

FL at LHeC

47

M. Klein, arXiv:1802.04317

x F

L

Q

2 = 2 GeV 2

10

5

10

4

10

3

0.5 1 LHeC H1 x F

L

Q

2 = 6.5 GeV 2

10

5

10

4

10

3

0.5 1 x F

L

Q

2 = 25 GeV 2

10

5

10

4

10

3

0.5 1 x F

L

Q

2 = 120 GeV 2

10

5

10

4

10

3

0.5 1 x F

L

Q

2 = 2 GeV 2

10

5

10

4

10

3

0.5 1 x F

L

Q

2 = 6.5 GeV 2

10

5

10

4

10

3

0.5 1 x F

L

Q

2 = 25 GeV 2

10

5

10

4

10

3

0.5 1 x F

L

Q

2 = 120 GeV 2

10

5

10

4

10

3

0.5 1