Essential question
Do recent flow and jet quenching measurements at RHIC and the
LH give new constraints for
LHC
f characterization
h
of
f the
h Quark
k Gluon
Gl
Plasma (QGP)?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
1
QGP Characterization?
Characterization of the QGP produced in RHIC and LHC
collisions requires
I.
Development of experimental constraints to map the
topological thermodynamic and transport coefficients
topological,
T (τ ), c s ( T ), η ( T ), ζ ( T ), α s ( T ), qˆ ( T ), ± sep ( τ ), e tc ?
II Development of quantitative model descriptions of
II.
these properties
Experimental Access:
9 Temp/time-averaged constraints as
a function of √sNN
(II)
(with similar expansion dynamics)
T , cs ,
η
,
ζ
, qˆ , α s , etc ?
s
s
(I) Expect space-time averages
to evolve with √sNN
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
2
The LHC energy density lever arm
Lacey et. al, Phys.Rev.Lett.98:092301,2007
M. Malek, CIPANP 2012
RHIC (0.2 TeV) Æ LHC (2.76 TeV)
¾ Power law dependence (n ~ 0
2)
0.2)
¾
increase ~ 3.3
¾ Multiplicity density increase ~ 2.3
¾ Æ <Temp> increase ~ 30%
Essential questions:
¾ How do the transport coefficients
η
cs ,
, qˆ , α s evolve with T?
s
¾ Any indication for a change in
coupling close to To?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
3
The Flow Probe
Anisotropic p
Idealized Geometry
ε Bj =
1 1 dET
π R2 τ0 dy
~ 5 − 45
GeV
fm3
ε=
Isotropic p
y2 − x2
y 2 + x2
⎛
⎛ ∂ε Bj ⎞ ⎞
⎜ P = ρ² ⋅⎜
⎟ ⎟⎟
∂
ρ
⎜
⎝
⎠ s/ρ ⎠
⎝
ε , cs ,
Crucial parameters
Actual collision profiles
f
are not smooth,
due to fluctuations!
Acoustic viscous modulation of vn
⎛ 2η 2 t ⎞
δ Tμν ( t , k ) = exp ⎜
k ⎟ δ Tμν ( 0 )
3
s
T⎠
⎝
η
s
, δ f, T f
Initial Geometry characterized by many
shape harmonics (εn) Æ drive vn
r cos ( nϕ part ) + r sin ( nϕ part )
n
εn =
2
n
2
rn
I iti l eccentricity
Initial
t i it (and
( d its
it attendant
tt d t fluctuations)
fl t ti
) εn drive
di
momentum anisotropy vn with specific scaling properties
Staig & Shuryak arXiv:1008.3139
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
4
2
PID flow excitation function @ RHIC
Flow saturates for
√sNN = 39-200 GeV
Soft region
g
of
EOS?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
5
Flow is partonic @ RHIC
vn PID scaling
KET & ( n q ) scaling validated for vn
Æ Partonic flow
n/2
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
6
arXiv:1105.3782
Acoustic Constraint
⎛ 2η 2 t ⎞
k ⎟ δ Tμν ( 0 )
3
s
T⎠
⎝
δ Tμν ( t , k ) = exp ⎜
2π R = nλg
Deformation
k=
RHIC
LHC
n
R
Characteristic viscous damping
of the harmonics validated
ÆImportant constraint
vn
η
s
εn
~
= α ⋅ exp ( − β n 2 )
1
4π
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
7
Eccentricity Constraint
arXiv:1105.3782
9Scaling validated for vn
9 Similar scaling at LHC
vn ( pT ) ∝ ( v2 )
n /2
9Centrality dependence reflect
eccentricity ratio
9Constraints for εn
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
8
Flow @ RHIC and the LHC
¾ Charge hadron flow
similar @ RHIC & LHC
¾ Particle ratio-weighted
PIDed flow results
reproduce inclusive
charged hadron flow
results at RHIC and
LHC respectively
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
9
Flow increases from RHIC to LHC
¾Flow increases from RHIC
to LHC
9 Sensitivity to EOS
9 increase in <cs>
¾ Proton flow blueshifted
[hydro prediction]
9 Role of radial flow
9Role of hadronic rescattering?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
10
Flow is partonic @ the LHC
0.15 Pb+Pb @ 2.76 TeV
π
05-10%
10-20%
20-30%
40-50%
30-40%
0.15
K
p
0.10
v2//nq
0.10
0.05
0.05
0.00
0.00
0.5 1.0 1.5
0.5 1.0 1.5
0.5 1.0 1.5
0.5 1.0 1.5
0.5 1.0 1.5
KET (GeV)
Scaling for partonic flow validated after
accounting for proton blueshift
9 Larger partonic flow
f
at the LHC
C
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
11
vn
Constraint for η/s & δf
εn
= α ⋅ exp ( − β n 2 )
Pb+Pb - 2.76 TeV
0.7 GeV/c
1.3 GeV/c
1.9 GeV/c
2.3 GeV/c0.25
Pb+Pb - 2.76 TeV
20-30%
1
1
20-30%
0.15
0.1
β v /ε
n n
vn/εn
0.20
0.1
0.10
⎛ β 2⎞
= α ⋅ exp ⎜ −
n ⎟
⎜
⎟
εn
p
T
⎝
⎠
vn
0.01
0.05
0.01
0.00
2
4
6
2
4
6
2
4
6
n
1
2
4
pT (GeV/c)
2
6
β scales as 1/√pT
9Important constraint
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
12
Constraint for η/s & δf
0.30
Hydro - Schenke et al.
20-30%
4πη/s = 1.25
0.25
α(pT)-1/2
4πη/s = 0.0
1.5
4πη/s = 1.25 δf~pT
0.20
β((pT)
Deformation
eo a o
n
k=
R
δ Tμν ( t , k ) = exp ( β n2 ) δ Tμν ( 0 )
0.15
0.10
Particle Dist. f = f 0 + δ f ( pT )
pT2−α
δ f ( pT ) ~
Tf
0.05
Characteristic pT dependence of β
Æ reflects the influence of δf and η/s
0.00
0
9 <η/s> similar at LHC and RHIC ~ 1/4π
1
2
pT ((GeV/c))
3
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
13
Jet quenching
Probe
Radiative Energy loss:
dE
~ σρ L kT2
dx
Suppression for ∆L
N (Δφ , pT ) ∝ [1 + 2v2 ( pT ) cos(2
(2Δφ )]
RAA (90o , pT ) 1 − 2v2 ( pT )
Rv2 ( pT , ΔL) =
=
RAA (00 , pT ) 1 + 2v2 ( pT )
Suppression for L
R AA ( pT , L) =
Yield AA
⟨ N binaryy ⟩ AA Yield pp
, Phys.Lett.B519:199-206,2001
y
,
Jet quenching drives RAA & azimuthal anisotropy with specific
scaling properties
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
14
Geometric Quantities for scaling
Phys. Rev. C 81, 061901(R) (2010)
B
A
ε n = cos n (φ −ψ n* )
L=R
ΔL ~ ε R
arXiv:1203.3605
σx & σy Æ RMS widths of density distribution
¾ Geometric fluctuations included
¾ Geometric quantities constrained by multiplicity density.
density
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
15
RAA Measurements - CMS
Eur. Phys. J. C (2012) 72:1945
arXiv:1202.2554
Centrality
dependence
pT dependence
Specific pT and centrality dependencies – Do they scale?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
16
L scaling of Jet Quenching - LHC
, Phys.Lett.B519:199-206,2001
arXiv:1202.5537
RAA scales with L, slopes
p (S
( L) encodes info on αs and q
q̂
9Compatible with the dominance of radiative energy loss
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
17
L scaling of Jet Quenching - RHIC
Phys.Rev.C80:051901,2009
RAA scales with L, slopes
p (S
( L) encodes info on αs and q
9Compatible with the dominance of radiative energy loss
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
18
pT scaling of Jet Quenching
, Phys.Lett.B519:199-206,2001
arXiv:1202.5537
ˆ
RAA scales as 1/√pT ; slopes (SpT) encode info on αs and q
9 L and 1/√pT scaling Æ single universal
ni ersal curve
c r e
9Compatible with the dominance of radiative energy loss
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
19
High-pT v2 measurements - CMS
pT dependence
arXiv:1204.1850
Centrality
dependence
Specific pT and centrality dependencies – Do they scale?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
20
High-pT v2 measurements - PHENIX
Au+Au @ 0.2 TeV
0
π
π±
0.25
10 - 20%
30 - 40%
20 - 30%
0.25
0.20
v2
0.20
0.15
0.15
0 10
0.10
0 10
0.10
0.05
0.05
0.00
0.00
0
5
10
0
5
10
0
5
10
pT (GeV/c)
Specific pT and centrality dependencies – Do they scale?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
21
High-pT v2 scaling - LHC
arXiv:1203.3605
v2 follows the pT dependence observed for jet quenching
Note the expected inversion of the 1/√pT dependence
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
22
Jet v2 scaling - LHC
Pb+Pb @ 2.76 TeV
ATLAS
10-20 (%)
20-30
30-40
40-50
0.10
0.15
v2
Jet
Jett - ATLAS
J
Hadrons
CMS
Hadron - -CMS
Hadrons - scaled (z ~ .62)
0.10
0.05
0
05
v2
0.05
0.00
0.00
-0.05
0.1
0.2
-1/2
0.3
-1/2
pT -1/2 (GeV/c) -1/2
0.05
0.10
Jet -1/2
(pT )
0.15
(GeV/c)
-1/2
v2 for Jets follows the pT dependence for jet quenching
Similar magnitude and trend for Jet and hadron v2 after scaling
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
23
∆L Scaling of high-pT v2
arXiv:1203.3605
Au+Au @ 0.2 TeV
0.2
10 - 20 (%)
20 - 30
30 - 40
0.4
0
0.1
0.2
0.0
0.0
v2/ΔL (fm--1)
v2
π
0.2 0.3 0.4 0.5
0.2 0.3 0.4 0.5
-1/2
-1/2
pT (GeV/c)
Combined ∆L and 1/√pT scaling Æ single universal curve for v2
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
24
∆L Scaling of high-pT v2
Au+Au @ 0.2 TeV
0.2
10 - 20 (%)
20 - 30
30 - 40
6 < pT < 9 (GeV/c)
01
0.1
04
0.4
v2//ΔL
v2
pT > 9
0.0
v2/Δ
ΔL
0.2
0.5
0.0
0.0
0
100
200
Npart
300
0.2
0.4
-1/2
pT
(GeV/c)
0.6
-1/2
Combined ∆L and 1/√pT scaling Æ single universal curve for v2
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
25
Jet suppression from high-pT v2 - LHC
arXiv:1203.3605
N (Δφ , pT ) ∝ [1 + 2v2 ( pT ) cos(2Δφ )]
RAA (90o , pT ) 1 − 2v2 ( pT )
Rv2 ( pT , ΔL) =
=
RAA (00 , pT ) 1 + 2v2 ( pT )
Jet suppression obtained directly from v2
ˆ
RV2 scales as 1/√p
√ T , slopes encodes info on αs and q
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
26
RAA (90o , pT ) 1 − 2v2 ( pT )
Rv2 ( pT , ΔL) =
=
RAA (00 , pT ) 1 + 2v2 ( pT )
Au+Au @ 0
0.2
2 TeV
10 - 20%
ln(R
R2)
0.2
30 - 40%
20 - 30%
0
π
10 - 20 (%)
20 - 30
30 - 40
0.5
0.0
0.0
-0.2
-0.5
-0.4
-1.0
-0
0.6
6
15
-1.5
-0.8
-1
ln(R2)/Δ
ΔL [fm ]
Jet suppression from high-pT v2 - RHIC
-2.0
-1.0
0.2
0.4
0.2
0.4
pT-1/2 (GeV/c)-1/2
0.2
0.4
0.2
0.4
-1/2
-1/2
pT (GeV/c)
Jet suppression obtained directly from v2
RV2 scales as 1/√pT , slopes encodes info on αs and q̂
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
27
Heavy quark suppression
Pb+Pb @ 2.76 TeV
0.0
ALICE
D (prompt)
6 - 12 GeV/c
ln(RAAA)
-0.5
-1.0
-1.5
0.5
1.0
1.5
L (fm)
2.0
Consistent
ˆ LHC
q
obtained from D’s
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
28
Extracted stopping power
arXiv:1202.5537
qˆ LHC
arXiv:1203.3605
GeV 2
~ 0.56
0 56
fm
Phys.Rev.C80:051901,2009
qˆ RHIC
GeV 2
~ 0.75
fm
ˆ LHC obtained from high-pT v and R [same α ] Æ similar
¾q
2
AA
s
ˆ
q
>
q
¾ RHIC
LHC - medium produced in LHC collisions less opaque!
Conclusion similar to those of Liao, Betz, Horowitz,
Æ Stronger coupling near Tc?
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
29
Summary
Remarkable scaling have been observed for both Flow and Jet Quenching
They lend profound mechanistic insights,
insights, as well as New constraints for
estimates of the transport and thermodynamic coefficients!
coefficients!
What do we learn?
¾ RAA and high-pT azimuthal anisotropy ¾ Flow is acoustic
stem from the same energy loss
9Flow is pressure driven
mechanism
9 Obeys the dispersion relation
¾ Energy loss is dominantly radiative
for sound propagation
¾ RAA and anisotropy measurements
¾Flow is partonic
give consistent estimates for <ˆq >
9 exhibits v n,q ( KET ) ~ v n2,2 /2q or v nn /2
(nq )
¾ RAA for D’s give consistent
scaling
estimates for <ˆq >
¾Constraints for:
¾ Magnitude and trend of Jet v2 similar
9initial geometry
tto scaled
l dh
d
hadron
v2
9 η/s similar at LHC and RHIC
¾The QGP created in LHC collisions is
~ 1/4π
less opaque than that produced at RHIC
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
30
E d
End
Roy A. Lacey, Stony Brook University; Jet Modification, Aug. 20-23, Wayne State, Detroit
31