EW and Npdf in HIC: Experimental Review

EW and nPDF in HIC: Experimental review

Andre Ståhl T.W. Bonner Laboratory, Rice University

Snowmass meeting, EF07: Electroweak and nPDF in HIC Introduction

• Parton PDFs modified by nuclear medium.

EPJ C79 035201 • Robust understanding of nPDF effects are crucial to interpret the heavy-ion measurements.

• Deviations from linear DGLAP evolution (i.e. saturation) should be enhanced in nuclei. CMS/ATLAS • Variety of probes can constrain nPDFs: ALICE 2 • W and Z bosons. Q Dijet • Low mass Drell-Yan and prompt photons. W/Z Top • Top quarks. • Dijet. DY • Heavy-Flavour in pPb. • Quarkonia and dijets in UPC. HF • Among others. LHCb x Snowmass meeting: EW & nPDF in HIC 23/11/2020 1 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects:

➢ CERN: ➢ LHC upgrades ➢ Future Circular Collider

➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US

Snowmass meeting: EW & nPDF in HIC 23/11/2020 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects: CMS/ATLAS ➢ CERN: ALICE 2 ➢ LHC upgrades Q ➢ Future Circular Collider W ➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US LHCb x Snowmass meeting: EW & nPDF in HIC 23/11/2020 W boson in pPb at 5.02 TeV ATLAS @ 5.02 TeV CMS @ 5.02 TeV ALICE @ 5.02 TeV pPb 34.6 nb-1 s = 5.02 TeV 140 NN + Luminosity uncertainty: 3.5% CMS W [nb] 120 lab η 100 + + JHEP 1702 (2017) 077

) / d W W ν

− + 80 W l P.L. B750 (2015) 565-586 →

+ 60

(W W+ → l+ + ν Data

σ 40

d pl > 25 GeV/c CT10 T 20 CT10+EPS09 ATLAS-CONF-2015-056 0 1.2

Ratio 1 0.8 −2 −1 0 1 2 η lab

• Measurements compatible with CT10 and CT10+EPS09 calculations. • Statistical precision of pPb data at 5.02 TeV limits sensitivity to nuclear PDF effects.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 2 W boson in pPb at 8.16 TeV CMS @ 8.16 TeV ALICE @ 8.16 TeV P.L. B800 (2020) 135048 pPb 173.4 nb-1 s = 8.16 TeV pPb 173.4 nb-1 s = 8.16 TeV ALI-PREL-351907 ALI-PREL-351903 NN NN 300 300 − 180 + + 180 − (nb) W → µ νµ CMS W → µ νµ CMS ALICE preliminary (nb) ALICE preliminary y pµ > 25 GeV/c + pµ > 25 GeV/c − 250 data + y 250 data − T T p−Pb, s = 8.16 TeV p−Pb, s = 8.16 TeV [nb] [nb] NN NN / d / d - 160 W 160 W W µ+ ← W+ W µ- ← W µ CM µ CM Data σ MCFM + CT14 σ MCFM + CT14 d d η η CT14 (68% CL) 200 p > 10 GeV/c 200 p > 10 GeV/c T T 140 140 CT14+EPPS16 (68% CL) MCFM + CT14 + EPPS16 MCFM + CT14 + EPPS16

) / d ) / d CT14+nCTEQ15 (68% CL) µ µ

ν ν 150 150

+ 120 − 120 µ µ Data 100 100 → CT14 (68% CL) →

+ 100 − 100 CT14+EPPS16 (68% CL)

(W CT14+nCTEQ15 (68% CL) (W 50 50

σ 80 σ 80 d Lumi. uncertainty (3.5%) not shown d Lumi. uncertainty (3.5%) not shown 0 0 1.2 1.2 −4 −2 024 −4 −2 024 1 1 y y cms cms 0.8 0.8 ALI−PREL−351907 ALI−PREL−351903

Ratio to CT14 −3 −2 −1 0 1 2 Ratio to CT14 −3 −2 −1 0 1 2 ηµ ηµ CM CM

• CMS results strongly deviate (>5σ) from CT14 PDF calculations in forward region. • Data provides clear evidence of nuclear modification of PDFs in pPb. • Experimental uncertainties are significantly smaller than nPDF uncertainties. • ALICE preliminary W+ results also deviate from CT14 by 2.7σ at forward rapidity.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 3 W boson in PbPb ATLAS @ 5.02 TeV

500 W + l + ATLAS [pb] → ν -1 l 450 Pb+Pb, sNN=5.02 TeV, 0.49 nb N η d d 400 evt

1 +

N 350

〉 W

AA 300 1 Data T 〈 250 CT14 pl,ν > 25 GeV EPPS16 T 200 mT > 40 GeV nCTEQ15 |η | < 2.5 0-80% 150 l

|η | E.P.J. C 79 (2019) no.11, 935 C79 (2019) no.11, E.P.J. 1 l Data Pred. 0.8 nPDF 0 0.5 1 1.5 2 2.5 |η | l

• Good agreement with CT14 while nPDF models underestimate the data by 10-20%.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 4 W boson in PbPb ATLAS @ 5.02 TeV E.P.J. C 79 (2019) no.11, 935 500 2.2 W + l + ATLAS ATLAS [pb] → ν -1 [nb] -1 l 450 + Pb+Pb, sNN=5.02 TeV, 0.49 nb 2 Pb+Pb, s =5.02 TeV, 0.49 nb

N NN η evt 1 d d

N W

400

ν evt

l 〉 1.8 1 +

N →

350 AA

〉

W W T

〈 1.6 AA 300 N 1 Data

T + + 〈 W → l ν: Data CT14 250 CT14 l,ν 1.4 l,−ν p > 25 GeV W −→ l −ν: Data CT14 p > 25 GeV EPPS16 T WT 200 mT > 40 GeV mT > 40 GeV nCTEQ15 |η | < 2.5 0-80% 1.2 〈T 〉 unc. |η | < 2.5 150 l AA l

|η | 〈N 〉 1 l 1 part Data Data Pred. Pred. 0.8 0.8 0 0.5 1 1.5 2 2.5 0 50 100 150 200 250 300 350 400 |η | N l 〈 part〉

Snowmass meeting: EW & nPDF in HIC 23/11/2020 4 W boson in PbPb ATLAS @ 5.02 TeV ALICE @ 5.02 TeV E.P.J. C 79 (2019) no.11, 935 arXiv:2008.07809v1 500 2.2 W + l + ATLAS ATLAS [pb] → ν -1 [nb] -1 l 450 + Pb+Pb, sNN=5.02 TeV, 0.49 nb 2 Pb+Pb, s =5.02 TeV, 0.49 nb

N NN η evt 1 d d

N W

400

ν evt

l 〉 1.8 1 +

N →

350 AA

〉

W W T

〈 1.6 AA 300 N 1 Data

T + + 〈 W → l ν: Data CT14 l, − 250 CT14 p ν > 25 GeV 1.4 − − pl,ν > 25 GeV − T W → l ν: Data CT14 T EPPS16 m > 40 GeV W 200 T mT > 40 GeV W nCTEQ15 |η | < 2.5 0-80% 1.2 |η | < 2.5 l 〈T 〉 unc. 150 AA l + |η | 〈N 〉 1 l 1 part Data Data

Pred. W Pred. 0.8 0.8 0 0.5 1 1.5 2 2.5 0 50 100 150 200 250 300 350 400 |η | N l 〈 part〉

• Good agreement with CT14 while nPDF models underestimate the data by 10-20%. • Centrality dependence not fully described by free-proton PDF. • Slight increasing trend for W− towards peripheral collisions. • First PbPb preliminary measurement of W at forward rapidity. • ALICE planning to combine 2015 y 2018 data.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 4 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

PHENIX ● Future HIC facilities and nPDF prospects: CMS/ATLAS ➢ CERN: ALICE 2 ➢ LHC upgrades Q ➢ Future Circular Collider Z ➢ China: ➢ Electron Ion Collider in China DY ➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US LHCb x Snowmass meeting: EW & nPDF in HIC 23/11/2020 Z boson in pPb ATLAS @ 5.02 TeV ALICE @ 8.16 TeV CMS @ 8.16 TeV LHCb @ 8.16 TeV 35 ATLAS 50 p+Pb 2013, L = 29 nb-1 int 30 s = 5.02 TeV NN 45 LHCb Preliminary FEWZ NNPDF31 [nb] µ

25 EPPS16 µ 40 FEWZ NNPDF31 + EPPS16 * [nb] Z →

Z s = 8.16 TeV FEWZ NNPDF31 + nCTEQ15 20 35 NN CT14 σ ll)/dy 15 30 Data → Data JHEP 2009 (2020) 076 (Z CT10 (NLO) 25 σ 10 CT10+EPS09 (NLO) d MSTW2008 (NNLO) 20 nCTEQ15 5 P.R. C92 (2015) no.4, 044915 nCTEQ15 15 1.5 EPPS16 10 EPPS16 CT10 5 1.0 CMS-PAS-HIN-18-003 LHCb-CONF-2019-003 Data / CT10 (NLO) 0 pPb Pbp 0.5 1.5 -2 0 2 pPb Pbp 1.0 Data / CT10+EPS09 (NLO)

Data/Model 0.5 EPS09 1.5 -2 0 2

1.0 Data / MSTW2008 (NNLO) 0.5 EPS09 -2 0 2 y * Z

• Results agree well with the (n)PDF calculations within current uncertainties. • New results from ALICE and CMS at 8.16 TeV are also compatible with all PDF models.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 5 Drell-Yan in pA PHENIX pAu @ 200 GeV PoS HP2018 PoS 345 (2019) 160

4.8 < M < 8.2 GeV Au p

• PHENIX preliminary pAu results show hint of enhancement at pT > 2 GeV in p-going side.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 6 Drell-Yan in pA PHENIX pAu @ 200 GeV CMS pPb @ 8.16 TeV CMS-PAS-HIN-18-003 15 < M < 60 GeV 15 < M < 60 GeV CT14 CT14

PoS HP2018 PoS 345 (2019) 160 EPPS16 EPPS16

4.8 < M < 8.2 GeV Au p

• PHENIX preliminary pAu results show hint of enhancement at pT > 2 GeV in p-going side. • CMS preliminary pPb results are consistent with both CT14 and EPPS16 calculations.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 6 Z boson in PbPb CMS @ 5.02 TeV ALICE @ 5.02 TeV ATLAS @ 5.02 TeV

ATLAS AA P.L. B802 (2020) 135262 -1 R Pb+Pb, sNN=5.02 TeV, 0.49 nb -1 1.2 pp, s=5.02 TeV, 25 pb JHEP 2009 (2020) 076 0-100% centrality CT14 CMS-PAS-HIN-19-003 nCTEQ15 CT14 1 CT14 nCTEQ15 + - 0.8 Z → l l EPPS16 EPPS166620 GeV EPPS16 NLO T EPPS16 0.6 nCTEQ15 NLO |η l|<2.5 0 0.5 1 1.5 2 2.5 1 Z Data

Theory |y | 0.8

0 0.5 1 1.5 2 2.5 |y|

• New results from CMS, ALICE (2015+2018) and ATLAS in 2020. • CMS cross-section measurements agree with PDF and nPDF calculations. • ALICE RAA data deviates from CT14 (int. yield ~ 3.4σ), and agrees with EPPS16 calculations. • ATLAS RAA results are compatible with CT14 while slightly underestimated by nPDF models.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 7 EW boson centrality dependence ALICE @ 5.02 TeV

CT14

EPS09

JHEP 2009 (2020) 076

• ALICE new Z boson results slightly favours nuclear PDFs over CT14.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 8 EW boson centrality dependence ALICE @ 5.02 TeV ATLAS @ 5.02 TeV arXiv:2003.11856

P.L. B802 (2020) 135262 W- CT14

EPS09 Z W+ JHEP 2009 (2020) 076

Snowmass meeting: EW & nPDF in HIC 23/11/2020 8 EW boson centrality dependence ALICE @ 5.02 TeV ATLAS @ 5.02 TeV CMS @ 5.02 TeV

P.L. B802 (2020) 135262 W- EPPS16 CT14 HG-PYTHIA EPS09 Z W+ CMS-PAS-HIN-19-003 JHEP 2009 (2020) 076

• ALICE new Z boson results slightly favours nuclear PDFs over CT14. • Z and W boson trend vs centrality shows slight enhancement towards peripheral collisions, not described by HG-PYTHIA model calculations → favours shadowing of σNN. • CMS Z boson data shows ‘suppression’ in peripheral events consistent with HG-Pythia. • Clear tension between ATLAS and CMS Z boson yields in peripheral PbPb.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 8 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects: CMS/ATLAS ➢ CERN: ALICE 2 ➢ LHC upgrades Q ➢ Future Circular Collider

➢ China: ➢ Electron Ion Collider in China γ ➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US LHCb x Snowmass meeting: EW & nPDF in HIC 23/11/2020 Prompt photons in pPb ALICE @ 5.02 TeV ATLAS @ 8.16 TeV

106 106 106 1.09 < η* < 1.90 -1.84 < η* < 0.91 -2.83 < η* < -2.02 105 105 105 [pb/GeV] [pb/GeV] [pb/GeV] T T T

E 104 E 104 E 104 /d /d /d σ σ σ d 103 d 103 d 103

2 2 2

10 ATLAS 10 P.L. 230-252 (2019) B796 10 s = 8.16 TeV p+Pb, 162 nb-1 10 10 10 Data 1 1 1 JETPHOX + CT14 + EPPS16 10−1 10−1 10−1 2 2 2 1.4 10 1.4 10 1.4 10 E [GeV] E [GeV] E [GeV] 1.2 T 1.2 T 1.2 T 1 1 1 E.P.J.W.C. 222 (2019) 02001 E.P.J.W.C. 0.8 0.8 0.8 Theory / Data 0.6 Theory / Data 0.6 Theory / Data 0.6 30 40 102 2 102 γ 30 40 102 2 102 γ 30 40 102 2 102 γ × ET [GeV] × ET [GeV] × ET [GeV]

• Cross-section measurements larger than nPDF NLO calculations by ~20% at low ET.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 9 Prompt photons in pPb ATLAS @ 8.16 TeV

6 6 Pb 6 Pb Pb 10 10 p 1.6 10 p 1.6 p 1.6 1.09 < η* < 1.90 R 1.09-1.84 < < ηη** << 0.911.90 R -2.83 <-1.84 η2.2* < -2.02< η* < 0.91 R -2.83 < η* < -2.02 105 105 105 [pb/GeV] [pb/GeV] [pb/GeV] ATLAS T T T 2 E 104 E 104 1.4 E 104 1.4 1.4

Backward pPb Data /d /d /d σ σ σ

R 1.8 d 103 d 103 d 103 JETPHOX + CT14 + EPPS16 1.2 1.2 / 1.6 1.2 102 ATLAS 102 102 JETPHOX + CT14 s = 8.16 TeV p+Pb, 162 nb-1 1.4 10 10 10 Forward pPb

1 1 R 1 Data 1.2 1 1 1 JETPHOX + CT14 + EPPS16 1 10−1 10−1 0.8 10−1 0.8 0.8 2 2 2 P.L. B796 (2019) 230-252 P.L. 1.4 10 1.4 ATLAS10 1.4 10 0.8 E [GeV] E [GeV] E [GeV] T T -1 JETPHOXT + CT14 -1 1.2 1.2 0.6 s = 8.16 TeV p+Pb,1.2 165 nb 0.6 0.6 s = 8.16 TeV p+Pb, 165 nb 0.6 1 1 1 1.09JETPHOX < η* < 1.90 + / CT14-2.83 < +η *EPPS16 < -2.02 Data 0.4 0.8 0.8 0.4 0.8 0.4 30 40 50 60 102 0.42 102 3 102

Theory / Data Theory / Data Theory / Data × × 0.6 0.6 0.6 γ E T 30 40 102 2×102 γ 30 40 30 4010502 2×102102γ 2 10302 40 10230 402×10502 γ 102 2 102 30 40 50 102 2 102 ET [GeV] ET [GeV] × γ ET [GeV] × γ × γ ET [GeV] ET [GeV] ET [GeV]

• Cross-section measurements larger than nPDF NLO calculations by ~20% at low ET. • However, RpPb and FB ratio well described by EPPS16 and CT14 calculations.

9 Snowmass meeting: EW & nPDF in HIC JETPHOX23/11/2020 Prompt photons in pPb ATLAS @ 8.16 TeV

106 106 106 1.09 < η* < 1.90 2.2 -1.84 < η* < 0.91 -2.83 < η2.2* < -2.02 105 105 105 [pb/GeV] [pb/GeV] ATLAS [pb/GeV] ATLAS T T 2 T 2 E 104 E 104 E 104 Backward pPb Backward pPb Data Data /d /d /d σ σ σ R R 1.8 1.8 d 103 d 103 JETPHOX + CT14 + EPPS16d 103 JETPHOX + nCTEQ15 / / 1.6 1.6 102 ATLAS 102 JETPHOX + CT14 102 JETPHOX + CT14 s = 8.16 TeV p+Pb, 162 nb-1 1.4 1.4 Forward pPb 10 10 Forward pPb 10 R R

Data 1.2 1.2 1 1 1 JETPHOX + CT14 + EPPS16 1 1 10−1 10−1 10−1 2 2 2 P.L. B796 (2019) 230-252 P.L. 1.4 10 1.4 0.8 10 1.4 10 0.8 E T [GeV] E T [GeV]-1 E T [GeV] -1 1.2 1.2 0.6 s = 8.16 TeV p+Pb, 165 nb1.2 0.6 s = 8.16 TeV p+Pb, 165 nb 1 1 1.09 < η* < 1.90 / -2.83 < η* < 1-2.02 1.09 < η* < 1.90 / -2.83 < η* < -2.02 0.4 0.4 0.8 0.8 30 40 50 60 100.82 2 102 3 102 30 40 50 60 102 2 102 3 102

Theory / Data Theory / Data Theory / Data × × × × 0.6 0.6 0.6 γ γ E T E T 30 40 102 2 102 γ 30 40 102 2 102 γ 30 40 102 2 102 γ × ET [GeV] × ET [GeV] × ET [GeV]

• Cross-section measurements larger than nPDF NLO calculations by ~20% at low ET. • However, RpPb and FB ratio well described by EPPS16 and CT14 calculations. • nCTEQ15 slightly under-predicts FB ratio at low ET.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 9 Direct photons in PbPb ALICE @ 2.76 TeV

) 5 2 10 c s Pb-Pb NN = 2.76 TeV -2 104 0-20% ALICE PDF: CTEQ6M5, FF: GRV 20-40% ALICE (n)PDF: CTEQ6.1M/EPS09,

(GeV 3 40-80% ALICE FF: BFG2

y 10 dir d γ T JETPHOX p N 2 2 d 10 PDF: CT10, FF: BFG2 T d

p nPDF: EPS09, FF: BFG2

10 (all scaled by N ) ev. coll N 1

π 1 2

10−1

Thermal photons 10−2 x 102 10−3

10−4 x 101

10−5

0 10−6 x 10

10−7 P.L. B754 (2016) 235-248

1 10 p (GeV/c) T

• Excess observed by ALICE at low pT compared to pQCD calculations.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 10 Prompt photons in PbPb ALICE @ 2.76 TeV ATLAS @ 2.76 TeV ) ) ) ) ) 5 2 2 2 2 2 10 JETPHOX err. c s ATLAS Pb-Pb NN = 2.76 TeV pp pp JETPHOX Pb+Pb/pp pp pp -2 JETPHOX EPS09/pp Pb+Pb sNN=2.76 TeV 4 0-20% ALICE PDF: CTEQ6M5, FF: GRV -1 10 uncertainty L = 0.14 nb 20-40% ALICE (n)PDF: CTEQ6.1M/EPS09, 1.5 1.5 1.5 1.5 int (GeV 3 40-80% ALICE FF: BFG2

y 10 dir d γ T JETPHOX p N 2 2 d 10 PDF: CT10, FF: BFG2 1 1 1 1 T d

p nPDF: EPS09, FF: BFG2

10 (all scaled by N ) ev. coll N 1

0.5 0.5 0.5 0.5

π 1 Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX ( 2 40-80%, |η| < 1.37 20-40%, |η| < 1.37 10-20%, |η| < 1.37 0-10%, |η| < 1.37 10−1

) 20 ) 20 ) 20 ) 20 −2 10 pp Photon p [GeV]pp Photon p [GeV]pp Photon p [GeV]pp Photon p [GeV] x 102 P.R. C93 (2016)T no.3, 034914 T T T 10−3 1.5 1.5 1.5 1.5

10−4 x 101 1 1 1 1 10−5

0 10−6 x 10 0.5 0.5 0.5 0.5

−7 P.L. B754 (2016) 235-248 Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX ( 10 40-80%, 1.52 ≤ |η| < 2.37 20-40%, 1.52 ≤ |η| < 2.37 10-20%, 1.52 ≤ |η| < 2.37 0-10%, 1.52 ≤ |η| < 2.37

1 10 0 0 0 0 p (GeV/c) 30 50 100 30 50 100 30 50 100 30 50 100 T Photon p [GeV] Photon p [GeV] Photon p [GeV] Photon p [GeV] T T T T

• Excess observed by ALICE at low pT compared to pQCD calculations. • Good agreement between ATLAS data and (n)PDF calculations across all bins.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 10 Prompt photons in PbPb ALICE @ 2.76 TeV ATLAS @ 2.76 TeV CMS @ 5.02 TeV 404 µb-1 PbPb / 27.4 pb-1 pp (5.02 TeV) ) ) ) ) ) 5 2 2 2 2 2 10 JETPHOX err. 2 c s ATLAS Pb-Pb NN = 2.76 TeV pp pp JETPHOX Pb+Pb/pp pp pp -2 JETPHOX EPS09/pp Pb+Pb sNN=2.76 TeV 4 0-20% ALICE PDF: CTEQ6M5, FF: GRV CMS -1 0-100 % 10 uncertainty L = 0.14 nb 20-40% ALICE (n)PDF: CTEQ6.1M/EPS09, 1.5 1.5 1.5 1.8 1.5 int γ (GeV 3 40-80% ALICE FF: BFG2 |η | < 1.44

y 10 dir d γ T JETPHOX 1.6 p N 2 T uncertainty 2 d 10 PDF: CT10, FF: BFG2 1 1 1 1 AA T d JHEP 07 (2020) 116 p nPDF: EPS09, FF: BFG2 Luminosity uncertainty

10 (all scaled by N ) 1.4 ev. coll N 1

0.5 0.5 0.5 0.5

π 1 Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX (

2 1.2 40-80%, |η| < 1.37 20-40%, |η| < 1.37 10-20%, |η| < 1.37 0-10%, |η| < 1.37 10−1 AA ) 20 ) 20 ) 20 1 ) 20

−2 R 10 pp Photon p [GeV]pp Photon p [GeV]pp Photon p [GeV]pp Photon p [GeV] x 102 P.R. C93 (2016)T no.3, 034914 T 0.8 T T 10−3 1.5 1.5 1.5 1.5 Data

10−4 x 101 0.6 Systematic uncertainty 1 1 1 1 −5 10 0.4 JETPHOX PbPb(EPPS16+CT14)/pp(CT14) 0 10−6 x 10 JETPHOX PbPb(nCTEQ15)/pp(CT14) 0.5 0.5 0.5 0.5

Ratio to JETPHOX ( Ratio to JETPHOX ( Ratio to JETPHOX ( 0.2 Ratio to JETPHOX ( −7 P.L. B754 (2016) 235-248 10 40-80%, 1.52 ≤ |η| < 2.37 20-40%, 1.52 ≤ |η| < 2.37 10-20%, 1.52 ≤ |η| < 2.37 0-10%,JETPHOX 1.52 ≤ PbPb(CT14)/pp(CT14)|η| < 2.37

1 10 0 0 0 0 0 p (GeV/c) 30 50 100 30 50 100 30 50 10020 40 6030 5080 100100 120 140 160 180 200 T Photon p [GeV] Photon p [GeV] Photon p [GeV] Photonγ p [GeV] T T T T ET [GeV]

• Excess observed by ALICE at low pT compared to pQCD calculations. • Good agreement between ATLAS high pT data and (n)PDF calculations. • CMS RAA at high ET compatible with unity: photons not significantly modified.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 10 Direct photons at RHIC PHENIX @ 200 GeV

P.R.L. 123 (2019) 022301

• Low pT photon yield shows scaling with (dNch/dη)1.25 regardless of collision system or energy.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 11 Direct photons at RHIC RHIC @ 200 GeV P.R.L. 022301 (2019) 123

• Low pT photon yield shows scaling with (dNch/dη)1.25 regardless of collision system or energy. • STAR results also show scaling but at much lower magnitude → STAR / PHENIX tension. • Intermediate pT results also show scaling for same collision energy, in agreement with pQCD.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 11 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects: CMS/ATLAS ➢ CERN: ALICE 2 ➢ LHC upgrades Q ➢ Future Circular Collider Top ➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US LHCb x Snowmass meeting: EW & nPDF in HIC 23/11/2020 Top quarks in HI CMS pPb @ 8.16 TeV CMS PbPb @ 5.02 TeV

-1 pp, 19.6 fb , ( s=8 TeV) CT10 CMS CMS σ (8.16 TeV) NNLO+NNLL Top++ -1 Data scaled by A ⋅ NNLO+NNLL PbPb, 1.7 nb , ( s = 5.02 TeV) σ (8 TeV) NN NNLO+NNLL CT14 2l +N EPPS16 NLO l+jets EPJC 77 (2017) 15 NNLO+NNLL Top++ OS b-tag CT14 NNLO x CT14 NLO NNLO+NNLL TOP++ eµ JHEP 1608 (2016) 029 2lOS

P.R.L. 119 (2017) 242001 arXiv:2006.11110

-1 pPb, 174 nb , ( s =8.16 TeV) CT10+EPS09 NN ⋅ K (Top++) NLO MCFM NNLO+NNLL -1 pp, 27.4 pb , ( s = 5.02 TeV) CT14 NNLO CT14+EPPS16 2 ⋅ K (Top++) (scaled by A ) NNLO+NNLL TOP++ l+jets NLO MCFM NNLO+NNLL NNPDF30 NNLO 2l +jets/l+N NNLO+NNLL TOP++ µ+jets OS b-tag JHEP 03 (2018) 115 e+jets Exp unc: stat, stat⊕syst Exp. unc.: stat stat ⊕syst Th unc: PDF, PDF⊕scale Th. unc.: pdf pdf ⊕scales

0 20 40 60 80 100 −2 0 2 4 6 8 σ [nb] σ [µb]

• First measurements of top quarks in HIC. • Current results in agreement with both PDF and nPDF models. • Large uncertainties due to lack of statistics. • Will be significantly improved with future high luminosity LHC and FCC.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 12 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects:

➢ CERN: ➢ LHC upgrades ➢ Future Circular Collider

➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US EIC

Snowmass meeting: EW & nPDF in HIC 23/11/2020 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects:

➢ CERN: ➢ LHC upgrades ➢ Future Circular Collider

➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US EIC

Snowmass meeting: EW & nPDF in HIC 23/11/2020 Future plans: LHC

• A Fixed Target Experiment (AFTER) at LHC: arXiv:1807.00603 • Build joint programme between LHCb and ALICE collaborations. • LHCb currently use gas targets injected in LHC beam pipe through SMOG. • Goal to collide p (Pb) beams against polarised gas targets at 115 (72) GeV.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 13 Future plans: LHC

• High Luminosity LHC (2028+): CERN-2017-007-M R1 R2 R3 R4 R5 • Major LHC upgrade to increase pp luminosity by ~x10 beyond design value. • Major detector upgrades: ALICE/LHCb in LS2 and CMS/ATLAS in LS3. • Increase of 2-3x HI data in first HL-LHC run (R4) compared to Run 1+2. • Proposal to increase LHC beam energy (pp 27 TeV, 17 pPb, HE-LHC).

Snowmass meeting: EW & nPDF in HIC 23/11/2020 13 Future plans: LHC

• Large Hadron electron Collider (LHeC, 2031+): CERN-ACC-2020-2 • Add a 60 GeV electron beam to LHC using an Energy Recovery Linac. • Proposal to install in 2 years at earliest LS4 (2031). • Expected e-A luminosity: ~6x1032cm-2s-1 (O(10) fb-1 for HL-LHC).

Snowmass meeting: EW & nPDF in HIC 23/11/2020 13 Future plans: LHC DY arXiv:1807.00603 • A Fixed Target Experiment (AFTER) at LHC: arXiv:1807.00603 nCTEQ15 AFTER@LHC • Build joint programme between LHCb and ALICE collaborations.

• LHCb currently use gas targets injected in LHC beam pipe through SMOG. 4 < M < 5 GeV 10 GeV < M • Goal to collide p (Pb) beams against polarised gas targets at 115 (72) GeV. W • High Luminosity LHC (2028+): CERN-2017-007-M EPPS16 • Major LHC upgrade to increase pp luminosity by ~x10 beyond design value. CMS • Major detector upgrades: ALICE/LHCb in LS2 and CMS/ATLAS in LS3. Run 3+4 • Increase of 2-3x HI data in first HL-LHC run (R4) compared to Run 1+2. CERN-LPCC-2018-07 • Proposal to increase LHC beam energy (pp 27 TeV, 17 pPb, HE-LHC).

• Large Hadron electron Collider (LHeC, 2031+): CERN-ACC-2020-2 LHeC • Add a 60 GeV electron beam to LHC using an Energy Recovery Linac. • Proposal to install in 2 years at earliest LS4 (2031). • Expected e-A luminosity: ~6x1032cm-2s-1 (O(10) fb-1 for HL-LHC). CERN-ACC-2020-2

Snowmass meeting: EW & nPDF in HIC 23/11/2020 13 Future Circular Collider (FCC)

• Several options been studied: • FCC-ee (2040-2060): E.P.J.S.T. 228 (2019), 261-623 • FCC-hh (pp and ions, 2060+): E.P.J.S.T. 228 (2019), 755–1107 • FCC-eh (ep and aA): LHeC + FCC, 2040+

Snowmass meeting: EW & nPDF in HIC 23/11/2020 14 Future Circular Collider (FCC)

• Several options been studied: • FCC-ee (2040-2060): E.P.J.S.T. 228 (2019), 261-623 • FCC-hh (pp and ions, 2060+): E.P.J.S.T. 228 (2019), 755–1107 • FCC-eh (ep and aA): LHeC + FCC, 2040+ • FCC design: • 100 km circular collider linked to CERN. • Require magnets of 16 T for pp @ 100 TeV / pPb @ 63 TeV / PbPb @ 39 TeV • PbPb luminosity (35 nb-1) per month up to ~3x full LHC PbPb programme.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 14 Future Circular Collider (FCC)

Milhano, HP2020 • Large increase of all pQCD cross-sections vs LHC: • Beauty increase by 6-fold • W/Z increases by 7-fold • top increases by 80-fold

Snowmass meeting: EW & nPDF in HIC 23/11/2020 14 Future Circular Collider (FCC)

FCC FCC

Milhano, HP2020

• Substantial increase of kinematic coverage in x-Q2 plane. • Reach small x region probing saturation at perturbative scales.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 15 Future Circular Collider (FCC)

FCC

Milhano, HP2020

• Substantial increase of kinematic coverage in x-Q2 plane. • Reach small x region probing saturation at perturbative scales. • Complementarity with LHeC providing full constraints to nPDFs.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 15 Future Circular Collider (FCC)

P.L. B746 (2015) 64-72

PbPb PbPb EMC pPb EMC

• Substantial increase of kinematic coverage in x-Q2 plane. • Reach small x region probing saturation at perturbative scales. • Complementarity with LHeC providing full constraints to nPDFs.

• Top quarks in HI provide strong constraints to gluon nPDF at Q=mtop.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 15 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects:

➢ CERN: ➢ LHC upgrades ➢ Future Circular Collider

➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US EIC

Snowmass meeting: EW & nPDF in HIC 23/11/2020 Electron Ion Collider in China (EicC)

Yuxiang Zhao, DIS 2019

• To be installed in the High Intensity Heavy-Ion Accelerator Facility in Huizhou city. • Use polarised beams of e (3.5 GeV) and p (ions) (20 GeV/u). • Precise measurements for nucleon spin structure with flavour separations. • Complimentary to the US EIC with higher CM energies. • Plan to start data taking in 2032.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 16 Outline

● EW boson and top quark measurements in HIC

➢ W boson ➢ Z boson and Drell-Yan ➢ Prompt photons ➢ Top quarks

● Future HIC facilities and nPDF prospects:

➢ CERN: ➢ LHC upgrades ➢ Future Circular Collider

➢ China: ➢ Electron Ion Collider in China

➢ USA: ➢ RHIC upgrades ➢ Electron Ion Collider in US EIC

Snowmass meeting: EW & nPDF in HIC 23/11/2020 Future plans: RHIC

• sPHENIX (2023+): arXiv:1501.06197 • Includes a Si tracker, Ecal, Hcal, TPC, vertex detectors and 1.5T B field. • Plan to start data taking in early 2023: p+p, p+Au and Au+Au. • Goal to collect 145B minbias Au+Au events → ~30x more than current data. • Focus on jet structure, quarkonium spectroscopy, parton energy loss and cold QCD matter studies.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 17 Future plans: RHIC

• STAR Forward Upgrade programme (2021+): SN0648 • Extend tracking system to forward region (2.5 < η < 4). • Reuse PHENIX Ecal and add new forward hadronic calorimeter. • Plan to start data taking in 2021 and run in parallel with sPHENIX. • Focus on forward jet (|η|>1), direct photon and Drell-Yan measurements.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 17 Future plans: RHIC P.R. D100 (2019) 014004

• sPHENIX (2023+): arXiv:1501.06197 EPPS16 • Includes a Si tracker, Ecal, Hcal, TPC, vertex detectors and 1.5T B field. • Plan to start data taking in early 2023: p+p, p+Au and Au+Au. • Goal to collect 145B minbias Au+Au events → ~30x more than current data. sPHENIX • Focus on jet structure, quarkonium spectroscopy, parton energy loss and cold QCD matter studies.

Zhenyu Ye, DIS 2019

• STAR Forward Upgrade programme (2021+): SN0648 EPPS16 • Extend tracking system to forward region (2.5 < η < 4). • Reuse PHENIX Ecal and add new forward hadronic calorimeter. • Plan to start data taking in 2021 and run in parallel with sPHENIX. STAR • Focus on forward jet (|η|>1), direct photon and Drell-Yan measurements.

• Both STAR and sPHENIX data will constrain the gluon nPDFs for Au.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 17 US Electron Ion Collider (EIC) arXiv:1212.1701 • EIC project (2030+): arXiv:1212.1701 • Accelerate polarised beams of: electrons using 400 MeV Linac and ions using AGS. • Collide e-A beams at ~20-140 GeV CME and ~1033-34 cm-2s-2 luminosity. • Ion species ranging from proton to Uranium. • Consider 2 IPs with general-purpose hermetic detectors.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 18 US Electron Ion Collider (EIC) arXiv:1212.1701 • EIC project (2030+): arXiv:1212.1701 • Accelerate polarised beams of: electrons using 400 MeV Linac and ions using AGS. • Collide e-A beams at ~20-140 GeV CME and ~1033-34 cm-2s-2 luminosity. • Ion species ranging from proton to Uranium. • Consider 2 IPs with general-purpose hermetic detectors.

• Main physics programme: • Hadron and nuclear matter tomography: TMD and spatial imaging.

• Main physics programme: • Hadron and nuclear matter tomography: TMD and spatial imaging. • Spin and flavour structure of nucleon.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 18 US Electron Ion Collider (EIC)

• EIC project (2030+): arXiv:1212.1701 • Accelerate polarised beams of: electrons using 400 MeV Linac and ions using AGS. • Collide e-A beams at ~20-140 GeV CME and ~1033-34 cm-2s-2 luminosity. • Ion species ranging from proton to Uranium. • Consider 2 IPs with general-purpose hermetic detectors.

• Main physics programme: P.R. D 96 (2017) 114005 • Hadron and nuclear matter tomography: TMD and spatial imaging. • Spin and flavour structure of nucleon. • Parton distributions in nuclei covering a wide range of x and Q2. • QCD at extreme parton densities: saturation.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 18 SUMMARY • Electroweak and nPDF measurements: • Observation of nuclear PDF effects in W boson production. • LHC pPb data provide constrains to current nPDF models. • First measurements of top quarks and Drell-Yan in HIC open new opportunities.

• High pT photon yields consistent with pQCD while low pT follow scales with charged particle multiplicity (tension between PHENIX and STAR). • Z/W bosons in PbPb sensitive to collision geometry (tension between ATLAS and CMS).

• Long-term of QCD global analysis: • Exploit data from future HIC facilities (HL-LHC, LHeC, FCC, EicC, EIC). • Several collision modes proposed: e-A, p-A, A-A and fixed target. • Scan over multiple dimensions: nPDFs, TMDs, flavour, spin, … • Extension to forward physics and low x-regime, probing gluon saturation.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 19 Thank you for your attention!

Snowmass meeting: EW & nPDF in HIC 23/11/2020 BACKUP

Snowmass meeting: EW & nPDF in HIC 23/11/2020 Dijet in pPb CMS @ 5.02 TeV -1 -1 55 < pave < 75 GeV 75 < pave < 95 GeV CMS pPb (35 nb ), pp (27.4 pb ) 1.4 T 1.4 T sNN = 5.02 TeV

P.R.L. 121 (2018) no.6, 062002 anti-kT R = 0.3 jets 1.2 1.2 p > 90 GeV, p > 20 GeV T,1 T,2 Δφ > 2π/3 1,2

pp 1 pp 1 pp NLO pQCD: CT14 pPb pPb Data DSSZ 0.8 0.8 Syst. uncert. EPS09 (ηj1 + ηj2) 1 xp ηdijet = ∼ ln 0.6 0.6 2 2 ( xPb ) −2 ave−1 0 1 2 −2 ave−1 0 1 2 ave 1.4 95 < p < 115η GeV 1.4 115 < p < η150 GeV 1.4 p > 150 GeV T dijet T dijet T ave (pT,j1 + pT,j2) p = ∼ Q 1.2 1.2 1.2 T 2

pp 1 pp 1 pp 1 pPb pPb pPb 0.8 0.8 0.8

0.6 0.6 0.6 −2 −1 0 1 2 −2 −1 0 1 2 −2 −1 0 1 2 EMC η η η Shadowing dijet dijet dijet • pPb/pp ratio deviate from unity in the small and large ηdijet regions.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 1 Dijet in pPb CMS @ 5.02 TeV -1 -1 55 < pave < 75 GeV 75 < pave < 95 GeV CMS pPb (35 nb ), pp (27.4 pb ) 1.4 T 1.4 T sNN = 5.02 TeV

P.R.L. 121 (2018) no.6, 062002 anti-kT R = 0.3 jets 1.2 1.2 p > 90 GeV, p > 20 GeV T,1 T,2 Δφ > 2π/3 1,2

pp 1 pp 1 pp 1 pPb pPb pPb 0.8 0.8 0.8 EPS09 0.6 0.6 0.6 −2 −1 0 1 2 −2 −1 0 1 2 −2 −1 0 1 2 EMC η η η Shadowing dijet dijet dijet • pPb/pp ratio deviate from unity in the small and large ηdijet regions. • EPS09 calculations match data at ηdijet < 1 , while DSSZ overpredict the results.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 1 Dijet in pPb

CMS @ 5.02 TeV -1 -1 pPb (35 nb ), pp (27.4 pb ) sNN = 5.02 TeV -1 -1 55 < pave < 75 GeV 75 < pave < 95 GeV CMS pPb (35 nb ), pp (27.4ave pb ) 1.4 T 1.4 T 115s < = 5.02p TeV < 150 GeV NN T CMS P.R.L. 121 (2018) no.6, 062002 anti-kT R = 0.31.4 jets 1.2 1.2 p > 90 GeV, p > 20anti-k GeV T R = 0.3 jets T,1 T,2 Δφ > 2π/3 p > 90 GeV, p > 20 GeV, Δφ > 2π/3 1,2 T,1 T,2 1,2

pp 1 pp 1 pp NLO pQCD: CT14 pPb pPb 1.2 DSSZ EPPS16 Data DSSZ 0.8 0.8 Syst. uncert. EPS09 EPS09 (ηj1 + ηj2) 1 xp ηdijet = ∼ ln 0.6 0.6 2 2 ( xPb ) 1 −2 ave−1 0 1 2 −2 ave−1 0 1 2 ave 1.4 95 < p < 115η GeV 1.4 115 < p < η150 GeV 1.4 p > 150 GeV T dijet T dijet T (pT,j1 + pT,j2) pp NLO pQCD: CT14 ave 1.2 1.2 1.2 Data (pPb/pp) 0.8 pT = ∼ Q Theory (pPb/pp) 2 Data uncert. DSSZ

pp 1 pp 1 pp 1

pPb pPb pPb EPS09 0.8 0.8 0.8 nCTEQ15 nCTEQ15 0.6 EPPS16 0.6 0.6 0.6 −2 −1 0 1 2 −2 −1 0 1 2 −2 −1 0 1 2 −2 −1 0 1 2 η η ηEMC η Shadowing dijet dijet dijet dijet • pPb/pp ratio deviate from unity in the small and large ηdijet regions. • EPS09 calculations match data at ηdijet < 1 , while DSSZ overpredicts the results. • Data incompatible with DSSZ and nCTEQ15, while agrees with EPS09 and EPPS16.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 1 Dijet in pPb ATLAS @ 5.02 TeV

pPb I 28 < p < 35 GeV, 28 < p < 35 GeV

ρ ATLAS sNN = 5.02 TeV T,1 T,2 1.6 35 < p < 45 GeV, 28 < p < 35 GeV

-1 T,1 T,2 P.R. no.3, (2019) 034903 C100 2015 pp data, 25 pb anti-k t R = 0.4 jets 35 < p < 45 GeV, 35 < p < 45 GeV T,1 T,2 2016 p+Pb data, 360 µb-1 2.7 < y * < 4 45 < p < 90 GeV, 28 < p < 35 GeV 1.4 1 T,1 T,2 45 < p < 90 GeV, 35 < p < 45 GeV T,1 T,2 45 < p < 90 GeV, 45 < p < 90 GeV 1.2 T,1 T,2

0.8

−3 −2 −1 0 1 2 3 y * 2

• pPb/pp ratio of jet pair yields is suppressed by 20% when sub-leading jet y2 > 0.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 2 Dijet in pPb ATLAS @ 5.02 TeV

pPb I 28 < p < 35 GeV, 28 < p < 35 GeV

ρ ATLAS sNN = 5.02 TeV T,1 T,2 1.6 35 < p < 45 GeV, 28 < p < 35 GeV

0.8

−3 −2 −1 0 1 2 3 y * Shadowing 2

• pPb/pp ratio of jet pair yields is suppressed by 20% when sub-leading jet y2 > 0. • Suppression observed in a rapidity region where nuclear shadowing is predicted.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 2 Impact of dijet pPb data on nPDFs EPPS16 with CMS dijet data E.P.J. C79 (2019) no.6, 511

• Significant reduction of EPPS16 uncertainties, specially in the forward region.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 3 Impact of dijet pPb data on nPDFs EPPS16 with CMS dijet data E.P.J. C79 (2019) no.6, 511

• Significant reduction of EPPS16 uncertainties, specially in the forward region. • Mainly impact the gluon nPDF, adding strong constrains across a large x range.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 3 Prompt D in pPb LHCb @ 5.02 TeV 2 2 pPb LHCb LHCb pPb LHCb LHCb R R EPS09LO sNN = 5 TeV EPS09LO sNN = 5 TeV 1.5 EPS09NLO 1.5 EPS09NLO nCTEQ15 nCTEQ15 JHEP 1710 (2017) 090 CGC 1 1

JHEP 1710 (2017) 090 0.5 0.5 -4.0 < y* < -2.5 2.5 < y* < 4.0 Backward Forward 0 0 0 2 4 6 8 10 0 2 4 6 8 10 p [GeV/c] p [GeV/c] T T

• LHCb data compatible with nPDF calculations both in forward and backward rapidities.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 4 Prompt D in pPb LHCb @ 5.02 TeV ALICE @ 5.02 TeV LHCb @ 5.02 TeV 2 2 pPb ALICEp−Pb, s =5.02 TeV pPb

NN pPb LHCb LHCb R 1.6 LHCb LHCb R s = 5 TeV Prompt D mesons, −0.96 < y < 0.04 R EPS09LO NN cms EPS09LO sNN = 5 TeV 1.4 Average D0, D+, D*+ 1.5 EPS09NLO 0 EPS09NLO D 1.5 1.2 nCTEQ15 nCTEQ15 JHEP 1710 (2017) 090 CGC 1 1 1 0.8 JHEP 1912 (2019) 092 JHEP 1710 (2017) 090 0.6 -0.96 < y* < 0.04

CGC (Fujii-Watanabe) 0.5 0.4 0.5 -4.0 < y* < -2.5 FONLL with EPPS16 nPDF 2.5 < y* < 4.0 Vitev et al.: power corr. + k broad + CNM Eloss Backward 0.2 T Forward

Kang et al.: incoherent multiple scattering 0 0 0 0 2 4 6 8 10 0 5 10 15 20 25 30 35 0 2 4 6 8 10 p (GeV/c) p [GeV/c] T p [GeV/c] T T

• LHCb data compatible with nPDF calculations both in forward and backward rapidities. • ALICE mid-rapidity measurements described EPPS16 nPDF results. • Significant deviation of RpPb from unity at low pT and at forward rapidity.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 4 Prompt D0 in pPb ATLAS @ 8.16 TeV LHCb @ 8.16 TeV 2 FB FB

R ATLAS Preliminary

1.8 R LHCb 8.16 TeV LHCb preliminary p+Pb s = 8.16 TeV NN EPPS16 0 1.6 0 D pPb Prompt D →K π nCTEQ15 1.4 LHCb 5 TeV LHCb-CONF-2019-004 1.2 1 1 0.8 0.6 -0.5 < |y*| < 0.5

ATLAS-CONF-2017-073 0.4 Forward, 0 < y* < 0.5 0.2 Backward, -0.5 < y* < 0 0.5 2.5 < |y*| < 4.0 0 5 10 15 20 25 30 0 2 4 6 8 10 p [GeV] p [GeV/c] T T

• ATLAS RFB at mid-rapidity shows no significant deviations from unity.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 5 Prompt D0 in pPb ATLAS @ 8.16 TeV LHCb @ 8.16 TeV 2 FB FB

R ATLAS Preliminary

1.8 R LHCb 8.16 TeV LHCb preliminary p+Pb s = 8.16 TeV NN EPPS16 0 1.6 0 D pPb Prompt D →K π nCTEQ15 1.4 LHCb 5 TeV LHCb-CONF-2019-004 1.2 1 1 0.8 0.6 -0.5 < |y*| < 0.5

ATLAS-CONF-2017-073 0.4 Forward, 0 < y* < 0.5 0.2 Backward, -0.5 < y* < 0 0.5 2.5 < |y*| < 4.0 0 5 10 15 20 25 30 0 2 4 6 8 10 p [GeV] p [GeV/c] T T

• ATLAS RFB at mid-rapidity shows no significant deviations from unity. • RFB from LHCb show a rising trend with pT, deviating from nPDF results at high pT.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 5 Impact of D meson pPb data on nPDFs nPDF with LHCb D meson data -4.5 < y* < -4.0 3.5 < y* < 4.0 arXiv:1906.02512 EPPS16 nCTEQ15

EPPS16 nCTEQ15

• Reduction of EPPS16 and nCTEQ15 uncertainties at forward and backward rapidities.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 6 Impact of D meson pPb data on nPDFs nPDF with LHCb D meson data arXiv:1906.02512

EPPS16 nCTEQ15

• Reduction of EPPS16 and nCTEQ15 uncertainties at forward and backward rapidities. • Impose tight constrains on the gluon densities, mainly at low x.

Snowmass meeting: EW & nPDF in HIC 23/11/2020 6