DIPSY, ropes and shoving
Transcript of DIPSY, ropes and shoving
Introduction
Rope fragmentation
Rope Shovingˇ
DIPSY, ropes and shoving
Leif Lönnblad
(with Christian Bierlich and Gösta Gustafson)
Department of Astronomyand Theoretical Physics
Lund University
CERN 2017-06-15
Ropes and Shoving 1 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Nature Phys. 13 (2017) 535-539
Ropes and Shoving 2 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Outline
String hadronisation in dense environments
Understanding Impact parameter geometry
From pp to pA to AA
[arXiv:1412.6259, arXiv:1607.04434, arXiv:1612.05132]
Ropes and Shoving 3 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Outline
String hadronisation in dense environments
→ Ropes and Shoving
Understanding Impact parameter geometry
From pp to pA to AA
[arXiv:1412.6259, arXiv:1607.04434, arXiv:1612.05132]
Ropes and Shoving 3 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Outline
String hadronisation in dense environments
→ Ropes and Shoving
Understanding Impact parameter geometry
→ DIPSY vs. Pythia8
From pp to pA to AA
[arXiv:1412.6259, arXiv:1607.04434, arXiv:1612.05132]
Ropes and Shoving 3 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Outline
String hadronisation in dense environments
→ Ropes and Shoving
Understanding Impact parameter geometry
→ DIPSY vs. Pythia8
From pp to pA to AA
→ resurrecting Fritiof in Pythia8
[arXiv:1412.6259, arXiv:1607.04434, arXiv:1612.05132]
Ropes and Shoving 3 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Lund Model
The tunnelling mechanism: P ∝ e−πm2
q⊥κ ≡ e−
πm2q
κ e−πp2
⊥
κ
The fragmentation function: p(z) = N(1−z)a
z e−bm2⊥/z
Many parameters depends (implicitly) on κ.
Ropes and Shoving 4 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Lund Model (short version)
The tunnelling mechanism: P ∝ e−πm2
q⊥κ ≡ e−
πm2q
κ e−πp2
⊥
κ
The fragmentation function: p(z) = N(1−z)a
z e−bm2⊥/z
Many parameters depends (implicitly) on κ.
Ropes and Shoving 4 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Lund Model
The tunnelling mechanism: P ∝ e−πm2
q⊥κ ≡ e−
πm2q
κ e−πp2
⊥
κ
The fragmentation function: p(z) = N(1−z)a
z e−bm2⊥/z
Many parameters depends (implicitly) on κ.
Ropes and Shoving 4 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Lund Model
The tunnelling mechanism: P ∝ e−πm2
q⊥κ ≡ e−
πm2q
κ e−πp2
⊥
κ
The fragmentation function: p(z) = N(1−z)a
z e−bm2⊥/z
Many parameters depends (implicitly) on κ.
Ropes and Shoving 4 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Overlapping strings
How do we treat strings that overlap in space–time?
Ropes and Shoving 5 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Take the simplest case of two simple, un-correlated, completely
overlapping strings, with opposite colour flow.
•
•
•
•
q1
q2
q3
q4
1/9: A colour-singlet
8/9: A colour-octet
The string tension affects all details in the Lund string
fragmentation.
It is proportional to the Casimir operator C(8)2 = 9
4C
(3)2 .
Ropes and Shoving 6 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Take the simplest case of two simple, un-correlated, completely
overlapping strings, with opposite colour flow.
•
•
•
•
q1
q2
q3
q4
1/9: A colour-singlet
8/9: A colour-octet
The string tension affects all details in the Lund string
fragmentation.
It is proportional to the Casimir operator C(8)2 = 9
4C
(3)2 .
Ropes and Shoving 6 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
And for parallel colour flows:.
•
•
•
•
q1
q2
q3
q4
1/3: An anti-triplet
2/3: A sextet
C(6)2 = 5
2C(3)2
The anti-triplet case is related to string junctions and baryon
production (popcorn mechanism).
Ropes and Shoving 7 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
And for parallel colour flows:.
•
•
•
•
q1
q2
q3
q4
1/3: An anti-triplet
2/3: A sextet
C(6)2 = 5
2C(3)2
The anti-triplet case is related to string junctions and baryon
production (popcorn mechanism).
Ropes and Shoving 7 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
A random walk in colour-space
3
6
3
10
8
8
1
[Biro, Nielsen, Knoll (1984)]
Ropes and Shoving 8 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Rope Model
Partially overlapping string pieces in impact parameter and
rapidity.
Reconnect to get colour singlets.
Random walk for the rest to get higher colour multiplets
(ropes).
The rope will break one string at the time.
Calculate an effective string tension of a break-up, e.g.
the first string to break in a sextet has an effective
κeff ∝ C62 − C3
2 = 32C3
2
The second breakup has standard κ ∝ C32
Rescale the PYTHIA8 parameters accordingly.
Ropes and Shoving 9 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Rope Model
Partially overlapping string pieces in impact parameter and
rapidity.
Reconnect to get colour singlets.
Random walk for the rest to get higher colour multiplets
(ropes).
The rope will break one string at the time.
Calculate an effective string tension of a break-up, e.g.
the first string to break in a sextet has an effective
κeff ∝ C62 − C3
2 = 32C3
2
The second breakup has standard κ ∝ C32
Rescale the PYTHIA8 parameters accordingly.
Ropes and Shoving 9 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Rope Model
Partially overlapping string pieces in impact parameter and
rapidity.
Reconnect to get colour singlets.
Random walk for the rest to get higher colour multiplets
(ropes).
The rope will break one string at the time.
Calculate an effective string tension of a break-up, e.g.
the first string to break in a sextet has an effective
κeff ∝ C62 − C3
2 = 32C3
2
The second breakup has standard κ ∝ C32
Rescale the PYTHIA8 parameters accordingly.
Ropes and Shoving 9 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Rope Model
Partially overlapping string pieces in impact parameter and
rapidity.
Reconnect to get colour singlets.
Random walk for the rest to get higher colour multiplets
(ropes).
The rope will break one string at the time.
Calculate an effective string tension of a break-up, e.g.
the first string to break in a sextet has an effective
κeff ∝ C62 − C3
2 = 32C3
2
The second breakup has standard κ ∝ C32
Rescale the PYTHIA8 parameters accordingly.
Ropes and Shoving 9 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Rope Model
Partially overlapping string pieces in impact parameter and
rapidity.
Reconnect to get colour singlets.
Random walk for the rest to get higher colour multiplets
(ropes).
The rope will break one string at the time.
Calculate an effective string tension of a break-up, e.g.
the first string to break in a sextet has an effective
κeff ∝ C62 − C3
2 = 32C3
2
The second breakup has standard κ ∝ C32
Rescale the PYTHIA8 parameters accordingly.
Ropes and Shoving 9 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
The Rope Model
Partially overlapping string pieces in impact parameter and
rapidity.
Reconnect to get colour singlets.
Random walk for the rest to get higher colour multiplets
(ropes).
The rope will break one string at the time.
Calculate an effective string tension of a break-up, e.g.
the first string to break in a sextet has an effective
κeff ∝ C62 − C3
2 = 32C3
2
The second breakup has standard κ ∝ C32
Rescale the PYTHIA8 parameters accordingly.
Ropes and Shoving 9 Leif Lönnblad Lund University
Introduction
Rope fragmentation
Rope Shovingˇ
Ropes and Shoving 10 Leif Lönnblad Lund University
Rope fragmentationˆ
Rope Shoving
DIPSY vs. PYTHIA8ˇ
Will overlapping strings in high multiplets generate a transverse
pressure?
[Abramovsky, Gedalin, Gurvich, Kancheli (1988)]
Ropes and Shoving 11 Leif Lönnblad Lund University
Rope fragmentationˆ
Rope Shoving
DIPSY vs. PYTHIA8ˇ
Rope Shoving
All strings are sliced into dy slices.
In each (small) time–step dt , each string will get a kick
from other strings:
dp⊥
dydt=
C0td
R2exp
(
− d2
2R2
)
.
Momentum conservation is observed.
Transverse kicks resolved pairwise.
Longitudinal recoil absorbed by kicking dipole.
“kick” → “kink” = gluon
Ropes and Shoving 12 Leif Lönnblad Lund University
Rope fragmentationˆ
Rope Shoving
DIPSY vs. PYTHIA8ˇ
Rope Shoving
All strings are sliced into dy slices.
In each (small) time–step dt , each string will get a kick
from other strings:
dp⊥
dydt=
C0td
R2exp
(
− d2
2R2
)
.
Momentum conservation is observed.
Transverse kicks resolved pairwise.
Longitudinal recoil absorbed by kicking dipole.
This could give rise to a Ridge!
“kick” → “kink” = gluon
Ropes and Shoving 12 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
DIPSY
[Avsar, Flensburg, Gustafson, Lönnblad (2005–2011)]
Ropes and Shoving 13 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
DIPSY
Formulated in impact parameter space and rapidity.
Implements BFKL evolution to leading log(++).
Naturally treats saturation and MPI.
“Trivial” to extend to pA and AA.
Does not describe pp Minimum Bias very well.
[Mueller, Patel (1994)]
Ropes and Shoving 14 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
DIPSY
Formulated in impact parameter space and rapidity.
Implements BFKL evolution to leading log(++).
Naturally treats saturation and MPI.
“Trivial” to extend to pA and AA.
Does not describe pp Minimum Bias very well.
[Mueller, Patel (1994)]
Ropes and Shoving 14 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
PYTHIA8
Describes pp Minimum Bias very well.
As well as most other things.
Does not have explicit impact parameter dependence.
Now available with a UserHooks
Cannot do heavy ions.
Yet!
UserHook written by Bierlich
Ropes and Shoving 15 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
PYTHIA8
Describes pp Minimum Bias very well.
As well as most other things.
Does not have explicit impact parameter dependence.
Now available with a UserHooks
Cannot do heavy ions.
Yet!
UserHook written by Bierlich
Ropes and Shoving 15 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
PYTHIA8
Describes pp Minimum Bias very well.
As well as most other things.
Does not have explicit impact parameter dependence.
Now available with a UserHooks
Cannot do heavy ions.
Yet!
UserHook written by Bierlich
Ropes and Shoving 15 Leif Lönnblad Lund University
Rope Shovingˆ
DIPSY vs. PYTHIA8
Fritiofˇ
PYTHIA8
Describes pp Minimum Bias very well.
As well as most other things.
Does not have explicit impact parameter dependence.
Now available with a UserHooks
Cannot do heavy ions.
Yet!
UserHook written by Bierlich
Ropes and Shoving 15 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
Simple picture of pp collisions
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
Simple picture of pp collisions
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
Simple picture of pp collisions
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
?
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
multiple soft gluon exchanges
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
Longitudinal excitation of both protons
P+dQ−
Q−P−
dQ+
Q+
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
String ends evenly distributed in rapidity
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
Hadronises as if doubly diffractive excitation
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
The picture in pA
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
The picture in pA
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings.
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
Remember Fritiof?
The picture in pA
Flat rapidity plateau.
High mass diffractions dσ/dM2X ∝ M
−2(1+ǫ)X were ǫ is small.
Works surprisingly well for√
s ≤ ISR.
Fritiof + Glauber gives heavy Ion collisions.
Works very well at low energies.
But at higher energies we need to worry about multiple
(semi-)hard parton–parton scatterings. PYTHIA8!
Ropes and Shoving 16 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
p
ν1
ν2
ν3
ν4
ν5
Ropes and Shoving 17 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
p
ν1
ν2
ν3
ν4
ν5
Ropes and Shoving 17 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
p
ν1
ν2
ν3
ν4
ν5
Ropes and Shoving 17 Leif Lönnblad Lund University
DIPSY vs. PYTHIA8 ˆ
Fritiof
Resultsˇ
p
ν1
ν2
ν3
ν4
ν5
IP
Ropes and Shoving 17 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
Does it work?
Ropes and Shoving 18 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
Does it work?
YES!
Ropes and Shoving 18 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
The ALICE plot with nuclei (DIPSY)
101 102 103
Nch, 2<|η|<4, p⟂ > 0.15 GeV
10-3
10-2
10-1
ratio to π
+π−
2K 0s /π
±
6φ/π±
2(Λ+Λ)/π±
6(Ξ+Ξ)/π±
16(Ω+Ω)/π±
e+ e−
DIPSY pp
Pythia8 + ropes
DIPSY pPb
DIPSY PbPb
[http://home.thep.lu.se/dipsy]
Ropes and Shoving 19 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
The Ridge!
Pythia 8 default
Pythia 8 + shoving
0.5
0.6
0.7
0.8
0.9
1.0The ridge, 2 < |∆η| < 4
dN
d∆
φ
-1 0 1 2 3 40.50.60.70.80.91.01.11.21.31.4
∆φ
Ra
tio
Ropes and Shoving 20 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
Centrality-dependent pseudo-rapidity distribution
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b bb b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b b bb b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b
b b b b b b b b b b b b b b b bb b b b b b
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b bb b
ATLASb
Fritiof/Pythia8
-2 -1 0 1 20
10
20
30
40
50
60
70
80
90
Centrality-dependent η distribution, pPb,√
SNN = 5 TeV.
η
(1/
Nev)
dN
ch/
dη
[arXiv:1508.00848]
Ropes and Shoving 21 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
Outlook
We have all the ingredients: Rope hadronisation String shoving Heavy Ions with PYTHIA8-improved Fritiof
Currently being implemented as a plug-in to/in PYTHIA8.
Ropes and Shoving 22 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
extra plots
Ropes and Shoving 23 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
b bb b b b
b b b b b b b b b b b b b b b b b b b b b b b b bb b b b
b b b bb b b b b b b b b b b b b b b
Datab
FritiofP8
Absorptive
0
2
4
6
8
10
Centrality 60-90%
dN
/d
η
-2 -1 0 1 2
0.6
0.8
1
1.2
1.4
MC
/D
ata
Ropes and Shoving 24 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b b bDatab
FritiofP8
Absorptive
0
20
40
60
80
100
Centrality 0-1%d
N/
dη
-2 -1 0 1 2
0.6
0.8
1
1.2
1.4
MC
/D
ata
Ropes and Shoving 25 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
bb
bbbb b b
bbbbbb
b
b
b
b
bb
b
b
b
b
b
b
b
b
b
b
b
b
b
b
Datab
FritiofP8
Absorptive
10−5
10−4
10−3
10−2
10−1
1
10 1
pPb @ 5.02 TeV, Inclusive charged 1.3 < η < 1.81
/(2
πp⊥)d
2N
/d
p⊥
/d
η(G
eV2c2
)
1 10 1 10 2
0.6
0.8
1
1.2
1.4
p⊥ [GeV]
MC
/D
ata
Ropes and Shoving 26 Leif Lönnblad Lund University
Fritiofˆ
Results
Outlook
bb
bb b b b b
bbbbbb
b
b
b
b
bb
b
b
b
b
b
b
b
b
b
b
b
b
b
b
Datab
FritiofP8
Absorptive
10−5
10−4
10−3
10−2
10−1
1
10 1
pPb @ 5.02 TeV, Inclusive charged −1.3 < η < −0.81
/(2
πp⊥)d
2N
/d
p⊥
/d
η(G
eV2c2
)
1 10 1 10 2
0.6
0.8
1
1.2
1.4
p⊥ [GeV]
MC
/D
ata
Ropes and Shoving 27 Leif Lönnblad Lund University