lpcc: lhec miniworkshop cern, april 18th...
TRANSCRIPT
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LHeC - Low x Kinematics
10-1
1
10
102
10-7
10-6
10-5
x
Q2/G
eV
2
x-610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q-110
1
10
210
310
410
510
610 )2(x,Q2,Anuclear DIS - F
Proposed facilities:
LHeC
Fixed-target data:
NMC
E772
E139
E665
EMC
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
(70 GeV - 2.75 TeV)
e-Pb (LHeC)
Electron-ion physics with
the LHeCNéstor Armesto
Departamento de Física de Partículas and IGFAEUniversidade de Santiago de Compostela
for the LHeC Study group, http://cern.ch/lhec 1
LPCC: LHeC miniworkshopCERN, April 18th 2013
Contents:
Electron-ion physics with the LHeC. 2
I. Introduction.
2. eA at the LHeC and comparison to the LHC.
3. Physics case in eA:● Inclusive measurements and nuclear PDFs.● Diffraction.● Final states: dynamics of QCD radiation and hadronization.
4. Summary and outlook.
CDR, arXiv:1206.2913, J. Phys. G 39 (2012) 075001;arXiv:1211.4831; arXiv:1211.5102
nPDFs:
3
Yellow Report on Hard Probes, 2004
● Lack of data ⇒ models give vastly different
results for the nuclear glue at small scales and x: problem for benchmarking in HIC.
● Available DGLAP analysis at NLO show large uncertainties at small scales and x.
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,1.69 GeVvu
PbR
EPS09nDSHKN07
DSSZFGS10
)2=4 GeV2(Q
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,1.69 GeVuPbR
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,1.69 GeVgPbR
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,100 GeVvu
PbR
EPS09nDSHKN07
DSSZFGS10
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,100 GeVuPbR
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,100 GeVgPbR
NLO analysis
Electron-ion physics with the LHeC: 1. Introduction.
R =fi/AAfi/p
≈ measuredexpected if no nuclear effects
nPDFs:
3
Yellow Report on Hard Probes, 2004
● Lack of data ⇒ models give vastly different
results for the nuclear glue at small scales and x: problem for benchmarking in HIC.
● Available DGLAP analysis at NLO show large uncertainties at small scales and x.
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,1.69 GeVvu
PbR
EPS09nDSHKN07
DSSZFGS10
)2=4 GeV2(Q
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,1.69 GeVuPbR
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,1.69 GeVgPbR
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,100 GeVvu
PbR
EPS09nDSHKN07
DSSZFGS10
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,100 GeVuPbR
-610 -510 -410 -310 -210 -110 10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
x
)2(x,100 GeVgPbR
NLO analysis
Inclusive J/ψ, 1202.1383Electron-ion physics with the LHeC: 1. Introduction.
R =fi/AAfi/p
≈ measuredexpected if no nuclear effects
4
Small x and saturation:
● QCD radiation of partons when x decreases leads to a large number of partons (gluons), provided each parton evolves independently (linearly, Δ[xg] ∝ xg).● This independent evolution breaks at high densities (small x or high mass number A): non-linear effects (gg→g, Δ[xg] ∝ xg - k(xg)2).
Electron-ion physics with the LHeC: 1. Introduction.
xGA(x,Q2s)
�R2AQ2
s
� 1 =⇥ Q2s ⇤ A1/3x⇥�0.3
4
Small x and saturation:
● QCD radiation of partons when x decreases leads to a large number of partons (gluons), provided each parton evolves independently (linearly, Δ[xg] ∝ xg).● This independent evolution breaks at high densities (small x or high mass number A): non-linear effects (gg→g, Δ[xg] ∝ xg - k(xg)2).
Electron-ion physics with the LHeC: 1. Introduction.
xGA(x,Q2s)
�R2AQ2
s
� 1 =⇥ Q2s ⇤ A1/3x⇥�0.3
DGLAP
BFKL
BK/JIMWLK
DILUTEREGION
DENSEREGION
saturat
ion scale
Q s(x)
ln Q
ln 1
/x
ln ,QCD
non-
pert
urba
tive
regi
on
DILUTEREGION
DENSEREGION
ln A
ln 1
/x
eAep
[fixed Q]
Status of small-x physics:● Three pQCD-based alternatives to describe small-x ep and eA data (differences at moderate Q2(>Λ2QCD) and small x):→ DGLAP evolution (fixed order perturbation theory).→ Resummation schemes: BFKL, CCFM, ABF, CCSS.→ Saturation (CGC, dipole models).● Non-linear effects (unitarity constraints) are density effects: where? ⇒ two-pronged approach at the LHeC: ↓ x / ↑ A.
5Electron-ion physics with the LHeC: 1. Introduction.
Relevance for the HI program:
6Electron-ion physics with the LHeC: 1. Introduction.
Relevance for the HI program:
6
● Nuclear wave function at small x: nuclear structure functions.
Electron-ion physics with the LHeC: 1. Introduction.
Relevance for the HI program:
6
● Nuclear wave function at small x: nuclear structure functions.
● Particle production at the very beginning: which factorisation in eA?
● How does the system behave as ∼ isotropised so fast?: initial conditions for plasma formation to be studied in eA.
Electron-ion physics with the LHeC: 1. Introduction.
Relevance for the HI program:
6
● Nuclear wave function at small x: nuclear structure functions.
● Particle production at the very beginning: which factorisation in eA?
● How does the system behave as ∼ isotropised so fast?: initial conditions for plasma formation to be studied in eA.
Electron-ion physics with the LHeC: 1. Introduction.
● Probing the medium through energetic particles (jet quenching etc.): modification of QCD radiation and hadronization in the nuclear medium.
Contents:
Electron-ion physics with the LHeC. 7
I. Introduction.
2. eA at the LHeC and comparison to the LHC.
3. Physics case in eA:● Inclusive measurements and nuclear PDFs.● Diffraction.● Final states: dynamics of QCD radiation and hadronization.
4. Summary and outlook.
CDR, arXiv:1206.2913, J. Phys. G 39 (2012) 075001;arXiv:1211.4831; arXiv:1211.5102
Accelerator:
8
eD: LeN=ALeA>∼3×1031 cm-2s-1
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
CDR numbers for luminosity, to be
considered now as lower bounds.
√s≃0.8 TeV/nucleon
Luminosity per nucleon
Kinematics:
9Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.Black: HERA Green:100+20
Q2sat,GB
2081/3Q2sat,GB
● Small-x demands 1 degree acceptance.● Higher luminosity would benefit high-x and Q2 studies.
Kinematics:
9Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.Black: HERA Green:100+20
Q2sat,GB
2081/3Q2sat,GB
● Small-x demands 1 degree acceptance.● Higher luminosity would benefit high-x and Q2 studies.
x-610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-110
1
10
210
310
410
510
610 )2(x,Q2,Anuclear DIS - F
Proposed facilities:
LHeCFixed-target data:
NMC
E772
E139
E665
EMC
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
(70 GeV - 2.75 TeV)
e-Pb (LHeC)
LHC vs. LHeC:
10x
-610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-210
-110
1
10
210
310
410
510 : QUltra-peripheral Q (|y| < 2.5)ΥLHC
(|y| < 2.5)ΨLHC J/
Nuclear DIS & DY data:NMC (DIS)SLAC-E139 (DIS)FNAL-E665 (DIS)EMC (DIS)FNAL-E772 (DY)
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
PbPb@LHC
Ax-710 -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
1
10
210
310
410
510
610
710
810
(x)2sat,PbQ
PresentDIS+DY
p+Pb LHC (7 TeV+2.75 TeV)
Present nuclear DISand Drell-Yan in p+A
= 6laby
= 4laby
= 2laby
= 0laby
pPb@LHC
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
x-610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-110
1
10
210
310
410
510
610 )2(x,Q2,Anuclear DIS - F
Proposed facilities:
LHeC
Fixed-target data:
NMC
E772
E139
E665
EMC
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
(70 GeV - 2.75 TeV)
e-Pb (LHeC)
ePb@LHeC
LHC vs. LHeC:
10
● The LHeC will explore a region overlapping with the LHC:➜ in a cleaner experimental setup;➜ on firmer theoretical grounds.
x -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-210
-110
1
10
210
310
410
510 : QUltra-peripheral Q (|y| < 2.5)ΥLHC
(|y| < 2.5)ΨLHC J/
Nuclear DIS & DY data:NMC (DIS)SLAC-E139 (DIS)FNAL-E665 (DIS)EMC (DIS)FNAL-E772 (DY)
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
PbPb@LHC
Ax-710 -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
1
10
210
310
410
510
610
710
810
(x)2sat,PbQ
PresentDIS+DY
p+Pb LHC (7 TeV+2.75 TeV)
Present nuclear DISand Drell-Yan in p+A
= 6laby
= 4laby
= 2laby
= 0laby
pPb@LHC
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
x-610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-110
1
10
210
310
410
510
610 )2(x,Q2,Anuclear DIS - F
Proposed facilities:
LHeC
Fixed-target data:
NMC
E772
E139
E665
EMC
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
(70 GeV - 2.75 TeV)
e-Pb (LHeC)
ePb@LHeC
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
11
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
11
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
ALICE, 1210.3615
ALICE, 1210.4520● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
11
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
CMS, 1210.5482
ALICE, 1212.2001
ATLAS, 1212.5198
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
11
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
ATLAS, 1303.2084
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
11
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
ATLAS, 1303.2084
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
● The existence of collective effects in pPb is somewhat unexpected.● Are they really final state? Do they exist also in eA?
Contents:
Electron-ion physics with the LHeC. 12
I. Introduction.
2. eA at the LHeC and comparison to the LHC.
3. Physics case in eA:● Inclusive measurements and nuclear PDFs.● Diffraction.● Final states: dynamics of QCD radiation and hadronization.
4. Summary and outlook.
CDR, arXiv:1206.2913, J. Phys. G 39 (2012) 075001;arXiv:1211.4831; arXiv:1211.5102
eA inclusive: comparison
13
● Good precision can be obtained for F2(c,b) and FL at small x (Glauberized 3-5 flavor GBW model, NA ’02).
F2cPb F2bPb
-510 -410 -310 -210 -1100
0.2
0.4
0.6
0.8
1
1.2
x
)2(x,5 GeVLF
PbR
EPS09nDSHKN07
FGS10AKST
Data: LHeC-510 -410 -310 -210 -110
0
0.2
0.4
0.6
0.8
1
1.2
x
)2(x,5 GeV2F
PbR
EPS09nDSHKN07
DSSZFGS10AKST
Data: LHeC
Electron-ion physics with the LHeC: 3. Physics case in eA.
Note the
scale!!!
Not optimized!
Nuclear PDFs at small x:
14
● F2 data substantially reduce the uncertainties in DGLAP analysis; inclusion of charm, beauty (new!); and FL (new!) also give constraints.
Electron-ion physics with the LHeC: 3. Physics case in eA.
Nuclear PDFs at small x:
14
● F2 data substantially reduce the uncertainties in DGLAP analysis; inclusion of charm, beauty (new!); and FL (new!) also give constraints.
0.20.40.60.81.01.21.4
0.20.40.60.81.01.21.4
0.00.20.40.60.81.01.21.4
10-4 10-3 10-2 10-1 110-4 10-3 10-2 10-1 110-4 10-3 10-2 10-110-4 10-3 10-2 10-10.00.20.40.60.81.01.21.4
10-4 10-3 10-2 10-110-4 10-3 10-2 10-1
Q2=100 GeV2
Q2=1.69 GeV2
EPS09NLOFit 1
EPS09NLOFit 1
Pb Pb Pb
(,
2 =100GeV
2 )Pb
(,
2 =1.69GeV
2 )Pb
F2 only
Valence
Sea
Glue
Electron-ion physics with the LHeC: 3. Physics case in eA.
Nuclear PDFs at small x:
14
● F2 data substantially reduce the uncertainties in DGLAP analysis; inclusion of charm, beauty (new!); and FL (new!) also give constraints.
0.20.40.60.81.01.21.4
0.20.40.60.81.01.21.4
0.00.20.40.60.81.01.21.4
10-4 10-3 10-2 10-1 110-4 10-3 10-2 10-1 110-4 10-3 10-2 10-110-4 10-3 10-2 10-10.00.20.40.60.81.01.21.4
10-4 10-3 10-2 10-110-4 10-3 10-2 10-1
Q2=100 GeV2
Q2=1.69 GeV2
EPS09NLOFit 1
EPS09NLOFit 1
Pb Pb Pb
(,
2 =100GeV
2 )Pb
(,
2 =1.69GeV
2 )Pb
F2 only
Valence
Sea
GlueF2 + F2c,b + FL
F2 only
Electron-ion physics with the LHeC: 3. Physics case in eA.
Diffraction in ep and shadowing:
15
e
● Diffraction is linked to nuclear shadowing through basic QFT (Gribov): eD to test and set the ‘benchmark’ for new effects.
1106.2019
Electron-ion physics with the LHeC: 3. Physics case in eA.
Diffraction in ep and shadowing:
15
e
● Diffraction is linked to nuclear shadowing through basic QFT (Gribov): eD to test and set the ‘benchmark’ for new effects.
1106.2019
Electron-ion physics with the LHeC: 3. Physics case in eA.
Elastic VM production in eA:
16
● For the coherent case, predictions available.
● Challenging experimental problem (neutron tagging in ZDC?).
coherent
incoherent
!*A " J/# A
W (GeV)
1/A
2 d
$/d
t (
µb
/GeV
2)
0
0.5
1
1.5
2
2.5
0 200 400 600 800 1000
Saturationeffects
Electron-ion physics with the LHeC: 3. Physics case in eA.
Transverse scan: elastic VM
17
● t-differential measurements give a gluon tranverse mapping of the hadron/nucleus.
Electron-ion physics with the LHeC: 3. Physics case in eA.
Transverse scan: elastic VM
17
● t-differential measurements give a gluon tranverse mapping of the hadron/nucleus.
● Large extent in t with good precision.● Sizable saturation effects expected.
Electron-ion physics with the LHeC: 3. Physics case in eA.
Dihadron azimuthal decorrelation:
18
● Dihadron azimuthal decorrelation:currently discussed at RHIC assuggestive of saturation.● At the LHeC it could be studied far from the kinematical limits.
Albacete-Marquet ’10 pTlead>3 GeVpTass>2 GeVzlead=zass=0.3
y=0.7Q2=4 GeV2
Electron-ion physics with the LHeC: 3. Physics case in eA.
xA<<xp
ΔΦ=Φ12
19
● Low energy: hadronization inside → formation time, (pre-)hadronic absorption,...
● LHeC: dynamics of QCD radiation and hadronization.● Most relevant for particle production off nuclei and for QGP analysis in HIC.
Radiation and hadronization:
● High energy: partonic evolution altered in the nuclear medium.
Electron-ion physics with the LHeC: 3. Physics case in eA.
∼ratio of FFs A/pz=phadr/pparton
ν=Estruck partonhadron rest frame
19
● Low energy: hadronization inside → formation time, (pre-)hadronic absorption,...
● LHeC: dynamics of QCD radiation and hadronization.● Most relevant for particle production off nuclei and for QGP analysis in HIC.
Radiation and hadronization:
● High energy: partonic evolution altered in the nuclear medium.
Electron-ion physics with the LHeC: 3. Physics case in eA.Fixed-target LHeC
∼ratio of FFs A/pz=phadr/pparton
ν=Estruck partonhadron rest frame
Jets:
20
● Jets: large ET even in eA.● Useful for studies of parton dynamics in nuclei (hard probes), and for photon structure.● Background subtraction, detailed reconstruction pending.
Electron-ion physics with the LHeC: 3. Physics case in eA.
DGLAP
BFKL
BK/JIMWLK
DILUTEREGION
DENSEREGION
saturat
ion scale
Q s(x)
ln Q
ln 1
/x
ln ,QCD
non-
pert
urba
tive
regi
on
DILUTEREGION
DENSEREGION
ln A
ln 1
/x
eAep
[fixed Q]
Summary:
21
● At an LHeC@CERN:➜ High-precision tests of collinear factorization(s) and determination of PDFs.➜ Unprecedented access to small x in p and A.➜ Novel sensitivity to physics beyond standard pQCD.➜ Stringent tests of QCD radiation and hadronization.➜ Transverse scan of the hadron/nucleus at small x.➜ ... with implications on our understanding of QGP.
● The LHeC will answer the question of saturation/non-linear dynamics. For that, ep AND eA essential!!!
Electron-ion physics with the LHeC.
Outlook:
22
● With CERN and NuPECC mandate to further motivate the physics case and produce a TDR around 2015, several items have to be done/improved:
➜ Refine DGLAP fits with flavour decomposition (include neutrino data, relax assumptions) and optimized FL scenarios, and LHC data.➜ Monte Carlo generators!!!➜ Studies on diffraction: separation of coherent from incoherent, ndPDFs, dijets,...➜ Large x, EW bosons.➜ Nuclear GPDs: nuclear DVCS etc.➜ eD.➜ Jet reconstruction, angular decorrelation...➜ ...
➝ Cooperation with EIC in some of these items desirable.Electron-ion physics with the LHeC.
Outlook:
22
● With CERN and NuPECC mandate to further motivate the physics case and produce a TDR around 2015, several items have to be done/improved:
➜ Refine DGLAP fits with flavour decomposition (include neutrino data, relax assumptions) and optimized FL scenarios, and LHC data.➜ Monte Carlo generators!!!➜ Studies on diffraction: separation of coherent from incoherent, ndPDFs, dijets,...➜ Large x, EW bosons.➜ Nuclear GPDs: nuclear DVCS etc.➜ eD.➜ Jet reconstruction, angular decorrelation...➜ ...
➝ Cooperation with EIC in some of these items desirable.Electron-ion physics with the LHeC.
Thanks for your attention!
Backup:
23Electron-ion physics with the LHeC.
LHC vs. LHeC:
24
ePb@LHeC
x -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-210
-110
1
10
210
310
410
510 : QUltra-peripheral Q (|y| < 2.5)ΥLHC
(|y| < 2.5)ΨLHC J/
Nuclear DIS & DY data:NMC (DIS)SLAC-E139 (DIS)FNAL-E665 (DIS)EMC (DIS)FNAL-E772 (DY)
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
PbPb@LHC
Ax-710 -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
1
10
210
310
410
510
610
710
810
(x)2sat,PbQ
PresentDIS+DY
p+Pb LHC (7 TeV+2.75 TeV)
Present nuclear DISand Drell-Yan in p+A
= 6laby
= 4laby
= 2laby
= 0laby
pPb@LHC
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
LHC vs. LHeC:
24
● The LHeC will explore a region overlapping with the LHC:➜ in a cleaner experimental setup;➜ on firmer theoretical grounds.
ePb@LHeC
x -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
-210
-110
1
10
210
310
410
510 : QUltra-peripheral Q (|y| < 2.5)ΥLHC
(|y| < 2.5)ΨLHC J/
Nuclear DIS & DY data:NMC (DIS)SLAC-E139 (DIS)FNAL-E665 (DIS)EMC (DIS)FNAL-E772 (DY)
(Pb, b=0 fm)2sQ
perturbative
non-perturbative
PbPb@LHC
Ax-710 -610 -510 -410 -310 -210 -110 1
)2 (G
eV2
Q
1
10
210
310
410
510
610
710
810
(x)2sat,PbQ
PresentDIS+DY
p+Pb LHC (7 TeV+2.75 TeV)
Present nuclear DISand Drell-Yan in p+A
= 6laby
= 4laby
= 2laby
= 0laby
pPb@LHC
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
CMS, 1201.3093
CMS, 1205.6334
ATLAS, 1210.6486
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
CMS, 1102.5435
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
ALICE, 1209.3715
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
CMS, 1105.2438
ALICE, 1109.2501
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
ALICE, 1210.3615
ALICE, 1210.4520● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
CMS, 1210.5482
ALICE, 1212.2001
ATLAS, 1212.5198
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
ATLAS, 1303.2084
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
LHC studies:
25
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
Electron-ion physics with the LHeC: 2. eA at the LHeC and comparison to the LHC.
ATLAS, 1303.2084
● PbPb:➜ EW bosons.➜ VMs in UPCs.➜ Ridge.➜ ...
● pPb:➜ Charged particles.➜ Ridge.➜ Flow.➜ Back-to-back correlations, central-forward and forward-forward?➜ EW bosons, DY?➜ VMs, HF?➜ UPCs?➜ Jets and interjet activity?➜ ...
● The existence of collective effects in pPb is somewhat unexpected.● Are they really final state? Do they exist also in eA?
LHeC scenarios:
26
● For FL: 10, 25, 50 + 2750 (7000); Q2≤sx; Lumi=5,10,100 pb-1 respectively; charm and beauty: same efficiencies in ep and eA.
10-310-310-3
I 50 3.5 Ca 5⋅10-3 ? 5⋅10-3 ? ? eCa
For F2
Electron-ion physics with the LHeC: 3. Physics case in eA.
Note: FL in eA
27
● FL traces the nuclear effects on the glue (Cazarotto et al ’08).● Uncertainties in the extraction of F2 due to the unknown nuclear effects on FL of order 5 % (larger than expected stat.+syst.) ⇒
measure FL or use the reduced cross section (but then ratios at two energies...).
NA, Paukkunen, Salgado, Tywoniuk, ‘10
Electron-ion physics with the LHeC: 3 Physics case in eA.
Elastic VM production in ep:
28
● Elastic J/ψ production appears as a candidate to signal saturation effects at work!!!
p p!
!r
!bx x!
z
(1 " z)!r1 " z
"# E
Linear, sensitivity to (xg)2.
Non-linear, saturation.
Electron-ion physics with the LHeC: 3 Physics case in eA.
Diffractive DIS on nuclear targets:
29
● Challenging experimental problem, requires Monte Carlo simulation with detailed understanding of the nuclear break-up.
● For the coherent case, predictions available.
0
0.05
0.1
0.15
10 -2
xIP=0.00001Q2=3 GeV2x IP
F 2D
10 -2
xIP=0.0001Q2=3 GeV2
10 -3 10 -1
xIP=0.001Q2=3 GeV2
10 -3 10 -1
xIP=0.01Q2=3 GeV2
00.020.040.060.08
0.1
10 -1 10 -1
xIP=0.0001Q2=30 GeV2
10 -2
xIP=0.001Q2=30 GeV2
10 -2
xIP=0.01Q2=30 GeV2
00.020.040.060.08
0.1
10 -1 10 -1 10 -2
xIP=0.001Q2=300 GeV2
10 -2
xIP=0.01Q2=300 GeV2
00.010.020.030.040.05
10-1
H1 fit BipsatbCGC
10-1
Pb
10-1
10-1
xIP=0.01Q2=3000 GeV2
βElectron-ion physics with the LHeC: 3 Physics case in eA.
5o<θπ<25o, xπ>0.01
Daleo et al. ’04Data: H1 ’04
formation timeeffects
Radiation and hadronization:
30
● Large (NLO) yields at small-x (H1 cuts, 3 times higher if relaxed).● Nuclear effects in hadronization at small ν (LO plus QW, Arleo ’03).
Electron-ion physics with the LHeC: 3 Physics case in eA.
Radiation and hadronization:
30
● Large (NLO) yields at small-x (H1 cuts, 3 times higher if relaxed).● Nuclear effects in hadronization at small ν (LO plus QW, Arleo ’03).
0
1500
3000
4500
6000
0
200
400
600
d!
"/d
xB
(nb
)
2 # Q2 # 8 GeV
2MSTW-DSS (ep)
MSTW-DSS (ePb)
nDS-DSS (ePb)
nDS-nFF (ePb)
EPS09-DSS (ePb)
60+7000
60+2750
8 # Q2 # 20 GeV
2
xBj
20 # Q2 # 70 GeV
2
pT $ 3.5 GeV0
70
140
10-6
10-5
10-4
d!
"/d
pT
(pb
/GeV
)
2 # Q2 # 4.5 GeV
2
1
10
MSTW-DSS
MSTW-DSS (Pb)
nDSS-DSS (Pb)
nDS-nFF (Pb)
EPS-DSS (Pb)
60+7000
60+2750
4.5 # Q2 # 15 GeV
2
1
10
pT (GeV)
15 # Q2 #70 GeV
2
1
10
3 4 5 6 7 8 9 10 15
Electron-ion physics with the LHeC: 3 Physics case in eA.
Radiation and hadronization:
30
● Large (NLO) yields at small-x (H1 cuts, 3 times higher if relaxed).● Nuclear effects in hadronization at small ν (LO plus QW, Arleo ’03).
Electron-ion physics with the LHeC: 3 Physics case in eA.
Outlook:
31
● With CERN and NuPECC mandate to further motivate the physics case and produce a TDR around 2015, several items have to be done/improved:
➜ Refine DGLAP fits with flavour decomposition (include neutrino data, relax assumptions) and optimized FL scenarios, and LHC data.➜ Monte Carlo generators!!!➜ Studies on diffraction: separation of coherent from incoherent, ndPDFs, dijets,...➜ Large x, EW bosons.➜ Nuclear GPDs: nuclear DVCS etc.➜ eD.➜ Jet reconstruction, angular decorrelation...➜ ...
➝ Cooperation with EIC in some of these items desirable.Electron-ion physics with the LHeC.
Outlook:
31
● With CERN and NuPECC mandate to further motivate the physics case and produce a TDR around 2015, several items have to be done/improved:
➜ Refine DGLAP fits with flavour decomposition (include neutrino data, relax assumptions) and optimized FL scenarios, and LHC data.➜ Monte Carlo generators!!!➜ Studies on diffraction: separation of coherent from incoherent, ndPDFs, dijets,...➜ Large x, EW bosons.➜ Nuclear GPDs: nuclear DVCS etc.➜ eD.➜ Jet reconstruction, angular decorrelation...➜ ...
➝ Cooperation with EIC in some of these items desirable.Electron-ion physics with the LHeC.
NuPECC LRP
Outlook:
31
● With CERN and NuPECC mandate to further motivate the physics case and produce a TDR around 2015, several items have to be done/improved:
➜ Refine DGLAP fits with flavour decomposition (include neutrino data, relax assumptions) and optimized FL scenarios, and LHC data.➜ Monte Carlo generators!!!➜ Studies on diffraction: separation of coherent from incoherent, ndPDFs, dijets,...➜ Large x, EW bosons.➜ Nuclear GPDs: nuclear DVCS etc.➜ eD.➜ Jet reconstruction, angular decorrelation...➜ ...
➝ Cooperation with EIC in some of these items desirable.Electron-ion physics with the LHeC.
Outlook:
31
● With CERN and NuPECC mandate to further motivate the physics case and produce a TDR around 2015, several items have to be done/improved:
➜ Refine DGLAP fits with flavour decomposition (include neutrino data, relax assumptions) and optimized FL scenarios, and LHC data.➜ Monte Carlo generators!!!➜ Studies on diffraction: separation of coherent from incoherent, ndPDFs, dijets,...➜ Large x, EW bosons.➜ Nuclear GPDs: nuclear DVCS etc.➜ eD.➜ Jet reconstruction, angular decorrelation...➜ ...
➝ Cooperation with EIC in some of these items desirable.Electron-ion physics with the LHeC.
Thanks for your attention!