Kent_2007

Hot matter at RHIC: hot physics
at Kent, STAR, PHENIX
Given at the Physics Department, Kent State University,
Ohio.
Mikhail Kopytine
Kent State University
http://www.star.bnl.gov/~kopytin/
April 10, 2007
1

1 Outline
What:
• Motivation
• Data and future directions
• Conclusions
2

1 Outline
What:
• Motivation
• Data and future directions
• Conclusions
How:
• Focus on recent developments (2005 →)
• Place them in historical and conceptual
context
2

3 Au+Au collisions at RHIC...
4

...look beautiful but messy – why make this mess?
4

...look beautiful but messy – why make this mess? are they complex or
simple?
4

simple? can we apply a perfect theory?
4

simple? can we apply a perfect theory? what do we learn from them?
4

4 A perfect theory approach may work in
QED/electro-weak realm...
Expansion in powers of α ≈ 1/137, higher orders matter less...
5

5 Coming to QCD...
Hard to get matrix elements:
• with αS ∼ 1, comparable contributions in all orders, series converge slowly
(if at all)
6

6 E.Fermi – an extreme view: forget about matrix
elements!
E.Fermi, ”High
Energy Nuclear
Events”, Progr.
Theor. Phys. 5,
No.4, 1950
(Yukawa theory,
no QCD!)
”When two nucleons collide with
very great energy in their center of
mass system this energy will be
suddenly released in a small volume
surrounding the two nucleons. ...
Since the interactions of the pion
ﬁeld are strong we may expect that
rapidly this energy will be distributed
among the various degrees of
freedom ... according to statistical
laws. ... It is realized that this
description of the phenomenon is
probably as extreme, although in the
opposite direction, as is the
perturbation theory approach.”
7

7 I.Ya.Pomeranchuk (1951), L.D.Landau (1953) – forget
about ”individual” particles!
Time evolution of non-viscous hydro with
freeze-out.
• ”Hot and dense” phase – no ”particles”,
mean free path λ ≪ L ⇒ relativistic
hydrodynamics of an ideal (non-viscous
and non-heat-conducting) liquid is
applicable.
• Free separation at temperature T ∼ mπ
and λ ∼ L, particles reappear.
8

8 QCD running coupling: ifrared slavery and asymptotic
freedom
Gross, Politzer, Wilczek
Remember ∆px∆x ≈ ¯h! Asymptotic freedom as seen in particle physics
experiments (F.Wilczek’s Nobel Lecture 2004)
9

9 Deconﬁnement
0
0.1
0.2
0.3
0.4
0.5
0.6
0.01 0.1 0.5
r [fm]
αqq (r,T)
912
3
lattice, T/Tc=
lattice (T=0)
Kaczmarek, Karsch, Zantow, Petreczky PRD70(074505) 2004
pQCD
1.05
1.5
6
QCD running coupling at T > Tc, showing screening of strong force, albeit at
relatively large distances.
10

10 A more intuitive picture...
11

10 A more intuitive picture...
Screening leads to deconﬁnement at high density or temperature. Analogous to
Debye screening in ordinary plasma, there is rD.
11

11 Phase transition ⇒ increase in the number of degrees of
freedom, EOS change
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
1.0 1.5 2.0 2.5 3.0 3.5 4.0
T/Tc
ε/T4 εSB/T4
3 flavour
2+1 flavour
2 flavour
F. Karsch Lect. Notes Phys. 583 (2002) 209 Pressure becomes excessive after
phase transition back to ordinary matter ⇒ ﬁreball may ”explode”.
12

12 Approaches in theory
• ”Freedom”: test the nature of the medium by falsifying
perturbative predictions. High pt, ”jet tomography”,
photons, leptons. Work with a subset of speciﬁc particles or
even expect QGP itself to be ”asymptotically free” ⇒
perturbative.
13

perturbative.
• ”Collectivism”: test the nature of the medium by falsifying
quasi-classical predictions. Bulk pt, collective excitation
modes (ﬂows), correlations, hydrodynamics. Expect QGP to
be a highly-excited quasi-macroscopic system.
13

perturbative.
• ”Collectivism”: test the nature of the medium by falsifying
quasi-classical predictions. Bulk pt, collective excitation
modes (ﬂows), correlations, hydrodynamics. Expect QGP to
be a highly-excited quasi-macroscopic system.
• Lattice QCD is not considered a ”paradigm”, it’s heavy
artillery, ultima ratio regum
13

13 Coming next...
• Experimental strategies
14

13 Coming next...
• Perturbative diagnostics
– high pt spectra (hadrons, γ)
– charm
14

13 Coming next...
• Perturbative diagnostics
– high pt spectra (hadrons, γ)
– charm
• Quasi-classical diagnostics
– ﬂow (hydro)
– mini-jets in the medium (dissipation ?!)
– hadro-chemistry
14

14 Strategy dilemmas in experiment
sacrifice
including leptons and gamma
rare = irrelevantphysics is in hadrons,
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
identify many particle IDs
15

PHOBOS
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
15

PHOBOS
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
BRAHMS
15

15 STAR — subsystems
recent Kent contributions: EEMC, ZDC SMD, computing infrastructure
16

16 STAR — strategy
PHOBOS
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
BRAHMS
17

16 STAR — strategy
STAR
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
BRAHMSPHOBOS
TPC is the key; relatively infrequent large events
17

18 STAR — computing challenges
• high volume of data → 109
events next year
• distributed resources and users
Solution: distributed computing (grid).
Projects with Kent contribution:
• grid collector (event catalog) – Wei-Ming Zhang
• database API, load-balancer – Mikhail Kopytine
19

19 STAR — Particle identiﬁcation — by dE/ dx
20

20 STAR — Particle identiﬁcation — by topology
About 10% of a central event.
V 0
:
K0
→ π+
π−
(1)
Λ → pπ−
(2)
¯Λ → ¯pπ+
(3)
and by extension:
Σ−
→ Λπ−
(4)
Ω−
→ ΛK−
(5)
Kinks:
K±
→ µ±
ν (6)
K±
→ π±
π0
(7)
21

22 PHENIX — photograph
Accepts θ = (90 ± 20)◦
, highly inhomogeneous B-ﬁeld up to 0.8T.
23

23 PHENIX — strategy
STAR
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
BRAHMSPHOBOS
24

23 PHENIX — strategy
STAR
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
PHENIX
BRAHMSPHOBOS
Technologically heterogeneous, high rate, limited acceptance, +
leptons and γ
24

24 Stopping — Longitudinal expansion — Energy density
25

dN/dy
y
y =
1
2
ln
„
1 + v
1 − v
«
= v + O(v3
) (8)
25

dN/dy
y ∆
000
000
000000
000
000
000000
000
000
000
000000
111
111
111111
111
111
111111
111
111
111
111111
z
t
v+ ∆ v
z
y =
1
2
ln
„
1 + v
1 − v
«
= v + O(v3
) (8)
Bjorken:
∆y ≈ ∆v =
∆z
t
(9)
25

dN/dy
y ∆
000
000
000000
000
000
000000
000
000
000
000000
111
111
111111
111
111
111111
111
111
111
111111
z
t
v+ ∆ v
z
y =
1
2
ln
„
1 + v
1 − v
«
= v + O(v3
) (8)
Bjorken:
∆y ≈ ∆v =
∆z
t
(9)
E = N
d E
dy
∆y = N
d E
dy
∆z
t
(10)
ǫ(t = tform) =
E
S∆z
=
N
Stform
d E
dy
≈
dN
dy
mt
Stform
(11)
25

25 Energy density
Np is number of participants. Energy density
> 1GeV/fm3
is believed to be adequate for the
phase transition.
26

25 Energy density
0 100 200 300
2
4
)yσxσ~PHENIX (A
)2/3
p~ NPHENIX (A
)2/3
p~ NSTAR (A
pN
130 GeV
/c]
2
[GeV/fmτBj
∈
PHENIX PRC71(2005)034908, STARnucl−ex/0311017
> 1GeV/fm3
phase transition.
26

25 Energy density
0 100 200 300
2
4
)yσxσ~PHENIX (A
)2/3
p~ NPHENIX (A
)2/3
p~ NSTAR (A
pN
130 GeV
/c]
2
[GeV/fmτBj
∈
PHENIX PRC71(2005)034908, STARnucl−ex/0311017
1 10 10
2
10
3
0
5
LHC
PHENIX [5%]
STAR [5%]
NA49 recalc. [<7%]
WA98 recalc. [5%]
E802/E917 recalc. [5%]
FOPI estimate [1%]
[GeV]NNs
)[GeV]p/(0.5Nη/dTdE
PHENIX PRC71 (2005) 034908
> 1GeV/fm3
phase transition.
26

26 High pt suppression — hadrons
27

27 High pt suppression — alternatives
RAA(pt) =
1
nevt
d2
NAA
dpt dy
Ncoll
σinel
pp
d2σpp
dpt dy
(12)
28

28 High pt suppression — hadrons — STAR and PHENIX
29

28 High pt suppression — hadrons — STAR and PHENIXR
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Au-Au 0-10% centralAAR
d-Au min. biasdAR
= 200 GeVNNs
charged hadrons
(GeV/c)Tp
0 1 2 3 4 5 6 7 8 9 10
dAR
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
neutral pions
charged hadrons
PHENIX
29

28 High pt suppression — hadrons — STAR and PHENIXR
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Au-Au 0-10% centralAAR
d-Au min. biasdAR
= 200 GeVNNs
charged hadrons
(GeV/c)Tp
0 1 2 3 4 5 6 7 8 9 10
dAR
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
neutral pions
charged hadrons
PHENIX
0 2
(GeV/c)Tp
4 6 8 10
0
0.5
1
1.5
2
d+Au FTPC-Au 0-20%
d+Au Minimum Bias
pT
(GeV/c)
Au+Au Central
RAB
(pT
)
STAR
29

29 High pt suppression — photons — spectra
(GeV/c)Tp
0 2 4 6 8 10 12 14 16 18
−25
10
−22
10
−19
10
−16
10
−13
10
−10
10
−7
10
−4
10
−1
10
2
10
PHENIXPRL94,232301(2005)
3
MinBias x 10
0
0 −10% x 10
−2
10−20% x 10
−4
20−30% x 10
−6
30−40% x 10
−8
40−50% x 10
−10
50−60% x 10
−12
60−70% x 10
−14
70−80% x 10
−16
80−92% x 10
200 GeV Au+Au Direct Photon
> scaled NLO pQCDcoll<N
dyTdpevtNTpπ2
γN2
1d2
(c/GeV)
Binary-collision scaled pQCD gets it
right
part
N
0 50 100 150 200 250 300 350
>6.0GeV/c)T(pAAR
0
0.5
1
1.5
2 200 GeV Au+Au Direct Photon
0π200 GeV Au+Au
PRL 94, 232301 (2005)
PHENIX
Photons are produced in participant
NN collisions with no initial state
modiﬁcation. The high pt
suppression in hadronic sector is not
an initial state eﬀect.
30

30 Charm
Matsui, Satz
mechanism of J/Ψ
suppression. PLB
178:416, 1986.
31

30 Charm
Matsui, Satz
mechanism of J/Ψ
suppression. PLB
178:416, 1986.
0
0.2
0.4
0.6
0.8
1 1.5 2
T/Tc
r [fm]
J/Ψ
Ψ’
χc
Y
Y’
χb
rD
rmed
Karsch Ericeira 2005
Open/closed SU(3)/SU(2); for r > rmed the q¯q force
is strongly modiﬁed by the colored medium; rD is
the Debye screening radius. Horizontal lines areq
r2
q¯q for charmonium states.
31

31 PHENIX — sources of electrons
32

photonic (calibrated out using γ converter of known thickness):
π0
→ γe+
e−
→ γ − conversion (13)
η, η′
, ρ, ω, φ → π0
→ γe+
e−
32

photonic (calibrated out using γ converter of known thickness):
π0
→ γe+
e−
η, η′
, ρ, ω, φ → π0
→ γe+
e−
non-photonic (wanted):
D+
→ e+
X (15)
D0
→ e+
X (16)
B → (17)
non-photonic (unwanted):
K → πeν (18)
(GEANT)
ρ, ω, φ → e+
e−
(19)
mt scaling of measured π0
spectra
32

32 PHENIX — non-photonic single electrons
33

(GeV/c)Tp
0 0.5 1 1.5 2 2.5 3 3.5 4
]
2
dy[(c/GeV)T)dN/dpTpπ(1/2
10
−8
10
−7
10
−6
10
−5
10
−4
10
−3
10
−2
10
−1
1
10
10
2
10
3
=200GeVNNs)/2 + X @−
+e
+
(e→Au+Au
min. bias
3
10×0 − 10 %
2
10×10 − 20 %
1
10×20 − 40 %
−1
10×40 − 60 %
−2
10×60 − 92 %
Best fit curve of pp
PHENIX PRL94, 082301 (2005)
33

(GeV/c)Tp
0 0.5 1 1.5 2 2.5 3 3.5 4
]
2
dy[(c/GeV)T)dN/dpTpπ(1/2
10
−8
10
−7
10
−6
10
−5
10
−4
10
−3
10
−2
10
−1
1
10
10
2
10
3
=200GeVNNs)/2 + X @−
+e
+
(e→Au+Au
min. bias
3
10×0 − 10 %
2
10×10 − 20 %
1
10×20 − 40 %
−1
10×40 − 60 %
−2
10×60 − 92 %
Best fit curve of pp
PHENIX PRL94, 082301 (2005)
coll
N
0 200 400 600 800 1000 1200
Coll
/dy/NedN
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
−4
x10
(mb)AA
/dy/TedN
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
−2
x10
centrality binned
min−bias
= 200 GeVsp + p at
<4.0)T(0.8<p
<4.0)T(0.8<p
PHENIX PRL94, 082301 (2005)
Believed to come from open heavy
ﬂavor decays, non-photonic electrons
do not show high pt suppression: the
spectra scale with binary collisions.
33

33 Future of charm: STAR Heavy Flavor Tracker
• charm production for J/Ψ signature
• clarify charm RAA story
• elliptic flow of D mesons – is flow partonic ? is c part of it ?
cτ ∝ 100 − 300µm. Reduce combinatorics by vertex-finding. 10 µm resolution.
34

34 Azimuthal asymmetry — ﬂow
(x, y) anisotropy → rescattering →
(px, py) anisotropy
35

34 Azimuthal asymmetry — flow
(x, y) anisotropy → rescattering →
(px, py) anisotropy
E
d3
N
d3p
=
1
2π
d2
N
pt dpt dy
{1 +
∞X
m=1
2vm cos[m(φ − Ψr)]} (20)
• flow starts early – perhaps before hydro is applicable (stopping stage)
• testifies to equilibration
• sensitive to pressure and density gradients
• flow is a multiparticle effect; there is “non-flow”
35

35 Directed ﬂow — Importance of impact vector
36

E
d3
N
d3p
=
1
2π
d2
N
pt dpt dy
{1 +
∞X
m=1
2vm cos[m(φ − Ψr)]} (21)
for v1, need to know 0 ≤ Ψr < 2π:
36

E
d3
N
d3p
=
1
2π
d2
N
pt dpt dy
{1 +
∞X
m=1
2vm cos[m(φ − Ψr)]} (21)
for v1, need to know 0 ≤ Ψr < 2π:
need to be able to distinguish the two !
36

36 Directed ﬂow — STAR ZDC SMD
37

n
+−
DX
ZDC
SMD
p,n
h
37

7 vertical and 8 horizontal SMD slats at 1/3 of ZDC depth measure transverse
asymmetry of spectator neutrons
37

• eﬀort spearheaded by Kent people
• besides ﬂow, contributes to strangelet search, UPC and spin physics
37

37 Directed ﬂow
n
+−
DX
ZDC
SMD
p,n
h
38

37 Directed ﬂow
beam(or y) − yη
−5 −4 −3 −2 −1 0
(%)1v
−6
−5
−4
−3
−2
−1
0
1
2
= 62 GeVNNsSTAR:
= 200 GeVNNsSTAR:
= 17.2 GeVNNsNA49:
beam fragments
(ZDC SMD)
STAR PRC 73 (2006) 034903
n
+−
DX
ZDC
SMD
p,n
h
38

37 Directed ﬂow
beam(or y) − yη
−5 −4 −3 −2 −1 0
(%)1v
−6
−5
−4
−3
−2
−1
0
1
2
= 62 GeVNNsSTAR:
= 200 GeVNNsSTAR:
= 17.2 GeVNNsNA49:
beam fragments
(ZDC SMD)
STAR PRC 73 (2006) 034903
n
+−
DX
ZDC
SMD
p,n
h
Charged-particles v1 from 3-particle cumulants in the projectile frame.
• monotonic around midrapidity
• Supports limiting fragmentation
• Antiﬂow !
38

38 Elliptic ﬂow and hydro ﬂuidity
39

)
-2
dN/dy 1/S ( fm
0 5 10 15 20 25 30
ε/2v
-0.05
0
0.05
0.1
0.15
0.2
0.25
HYDRO limits
= 130 GeVNN
S√
= 17 GeVNN
S√
E877
NA49
STAR
STAR PRC66 (2002) 034904
(cumulant v2). Hydro limits by
Kolb, Sollfrank, Heinz, PRC62
(2000) 054909.
39

)
-2
dN/dy 1/S ( fm
0 5 10 15 20 25 30
ε/2v
-0.05
0
0.05
0.1
0.15
0.2
0.25
HYDRO limits
= 130 GeVNN
S√
= 17 GeVNN
S√
E877
NA49
STAR
STAR PRC66 (2002) 034904
(cumulant v2). Hydro limits by
Kolb, Sollfrank, Heinz, PRC62
(2000) 054909.
• v2 is a response to excentricity
ε = (y2 − x2)/(y2 + x2)
• low viscosity ⇐⇒ high
cross-sections ! ”sQGP”.
39

39 Elliptic ﬂow and quark coalescence/n2vData/Fit
/n (GeV/c)tp
0
0.05
Polynomial Fit
−π++π
0
SK
−
+K+
K
pp+
Λ+Λ
0 1 2
0.5
1
1.5
STAR
STAR PRC 72 (2005) 014904
dN
dφ
∝ 1 + 2v2 cos(2φ) (22)
dNclscnc,n
dφ
(pt) ∝
„
dN(pt
n
)
dφ
«n
(23)
(1 + 2v2 cos(2φ))n
= (24)
1 + 2v2n cos(2φ) + O(v2
2)
STAR AuAu 200 GeV minbas; n is number of constituent quarks. Expect
universality if quark coalescence dominates hadronization after the universal
ﬂow sets in. Valid at pt/n > 0.6 GeV/c for K0
S,K±
,p,¯p,Λ,¯Λ.
40

40 Local hadron density ﬂuctuations and Discrete Wavelet
Transform (DWT)
41

Transform (DWT)
Fλ
m,l,k(φ, η)–Haar wavelet orthonormal basis in (φ, η). scale ﬁneness (m),
directional modes of sensitivity (λ), track density ρ(η, φ, pt), locations in
2D (l, k). DWT is an expansion in this basis.
41

Transform (DWT)
Fλ
Power of local ﬂuctuations, mode λ:
Pλ
(m) = 2−2m
X
l,k
ρ, Fλ
m,l,k
2
(25)
41

Transform (DWT)
Fλ
Pλ
(m) = 2−2m
X
l,k
ρ, Fλ
m,l,k
2
(25)
“dynamic texture”:
Pλ
dyn(m) ≡ Pλ
true(m) − Pλ
mix(m) (26)
41

Transform (DWT)
Fλ
Pλ
(m) = 2−2m
X
l,k
ρ, Fλ
m,l,k
2
(25)
“dynamic texture”:
Pλ
dyn(m) ≡ Pλ
true(m) − Pλ
mix(m) (26)
Normalized:
Pλ
dyn(m)/Pλ
mix(m)/n(pt) (27)
41

41 Longitudinal minijet broadening – wavelet-based
technique
0
0.05
0.1
x 10
−2
10
−1
1
P
λdyn/P
λmix/N
ηφ mode
δη=1
δφ=π
10
−1
1
pt (GeV/c)
φ mode
δη=1/2
δφ=π/2
10
−1
1
η mode
δη=1
δφ=π
STAR PRC71 (2005) 031901 (R)
Central events: normalized dynamic texture for ﬁneness scales m = 0, 1, 0 from
left to right panels, respectively, as a function of pt. 000
000
000
000
111
111
111
111
STAR data; solid line –
Hijing without jet quenching; dashed line – Hijing with quenching; peripheral
STAR data renormalized to compare.
42

42 Longitudinal minijet broadening – traditional technique
r(p1, p2) ≡ ρsib(p1, p2)/ρmix(p1, p2). (28)
43

42 Longitudinal minijet broadening – traditional technique
r(p1, p2) ≡ ρsib(p1, p2)/ρmix(p1, p2). (28)
(a)
φ∆
N(r−1)
η
∆
(b)
φ∆
N(r−1)
η
∆
(c)
φ∆
N(r−1)
η
∆
(d)
φ∆
N(r−1)
η
∆
φ∆
N(r−1)
η
∆
000
000
000000
000
111
111
111111
111
000
000
000000
000
111
111
111111
111
000
000
000000
000
111
111
111111
111
000
000
000000
000
111
111
111111
111
000
000
000000
000
111
111
111111
111
000
000
000000
000
111
111
111111
111
0000
0000
00000000
0000
1111
1111
11111111
1111
000
000
000000
000
111
111
111111
111
STAR PRC73 (2006) 064907
−2
−1
0
1
2
0
2
4
−4
−3
−2
−1
0
1
2
3
4
5
6
−2
−1
0
1
2
0
2
4
−4
−3
−2
−1
0
1
2
3
4
5
6
−2
−1
0
1
2
0
2
4
−4
−3
−2
−1
0
1
2
3
4
5
6
−2
−1
0
1
2
0
2
4
−4
−3
−2
−1
0
1
2
3
4
5
6
Two-particle charge-idependent joint
correlations ¯N(ˆr − 1) on (η∆ ≡ η1 − η2,
φ∆ ≡ φ1 − φ2) for central (a) to
peripheral (d) collisions.
43

43 Connecting DWT and two-point correlation measures
44

X(t)
t
t t
t
t
t
autocorrelation
)A( ) = X(t)X( ∆∆ +
+ ∆
44

X(t)
t
t t
t
t
t
autocorrelation
)A( ) = X(t)X( ∆∆ +
+ ∆
−0.4
−0.2
0.2
0.4
0.6
0.8
−2 −1 1 2
W(
t
)∆t
∆
44

X(t)
t
t t
t
t
t
autocorrelation
)A( ) = X(t)X( ∆∆ +
+ ∆
−0.4
−0.2
0.2
0.4
0.6
0.8
−2 −1 1 2
W(
t
)∆t
∆
P(m) =
Z ∞
−∞
X(t∆/2)X(−t∆/2)W(t∆, m) dt∆, (29)
44

X(t)
t
t t
t
t
t
autocorrelation
)A( ) = X(t)X( ∆∆ +
+ ∆
−0.4
−0.2
0.2
0.4
0.6
0.8
−2 −1 1 2
W(
t
)∆t
∆
P(m) diﬀerentiates correlation on
scale m. Minijet elongation ⇒
correlation broadening ⇔ reduced
correlation gradient ⇔ reduced
“texture”
P(m) =
Z ∞
−∞
X(t∆/2)X(−t∆/2)W(t∆, m) dt∆, (29)
44

44 Future of wavelet correlations: Kent — P.N.Lebedev —
MEPhI project
Dremin et al.,
Phys.Lett.B499:97-103,2001.
Emulsion plates exposed at
SPS.
Top image → DWT →
suppress certain scales →
inverse DWT → bottom
image.
Rings of Cherenkov gluons ?
Could determine ”dielectric
permeability” of QCD matter
at RHIC.
45

45 Resonances in hadronic matter
Markert, Torrieri, Rafelski, Campos do Jordao 2002
46

¯K∗0
(892) → π+
+ K−
(30)
K∗0
(892) → π−
+ K+
(31)
Λ(1520) → p + K−
(32)
46

¯K∗0
(892) → π+
+ K−
(30)
K∗0
(892) → π−
+ K+
(31)
Λ(1520) → p + K−
(32)
0
m=ΣE
2
−(Σp)
2
0
N
46

¯K∗0
(892) → π+
+ K−
(30)
K∗0
(892) → π−
+ K+
(31)
Λ(1520) → p + K−
(32)
0
m=ΣE
2
−(Σp)
2
0
N
0
m=ΣE
2
−(Σp)
2
15.00
N
?
46

/dychdN
-100 0 100 200 300 400 500 600 700
resonance/non-resonance
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
p+p
Au+Au
= 200 GeVNN
s x 2.9
-
K*/K
x 3.5Λ*/Σ
x 10.8Λ*/Λ
x 8.1
-
/Kφ
UrQMD
Thermalmodel
STAR PRL 97, 132301 (2006): a thermal model with rescattering. Can use
models to put limits on the system evolution time.
47

47 QGP: physical reality or a justiﬁable ansatz?
48

azimuthal
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
asymmetry
48

photonic HBT
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
direct photons
HBT puzzle
asymmetry
azimuthal
mini−
jets
dileptons
48

48 So what happened at RHIC ? Conclusions so far:
photonic HBT
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
direct photons
HBT puzzle
asymmetry
azimuthal
mini−
jets
dileptons
49

photonic HBT
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
direct photons
HBT puzzle
asymmetry
azimuthal
mini−
jets
dileptons
• ﬁrst phase of the campaign: unexpectedly, a lot of action is taking place
on the South-Western front!
49

photonic HBT
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
direct photons
HBT puzzle
asymmetry
azimuthal
mini−
jets
dileptons
on the South-Western front! (of minimum-bias hadronic correlations)
49

photonic HBT
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
direct photons
HBT puzzle
asymmetry
azimuthal
mini−
jets
dileptons
• QGP as a theory ansatz may have been justiﬁed by the data
49

photonic HBT
QGP
sQGP
want
large
acceptance
to study
collective
effects
and
correlations
can
acceptance
to improve
quality of
particle ID
and
tracking
sacrifice
high pt
suppression
direct photons
HBT puzzle
asymmetry
azimuthal
mini−
jets
dileptons
• QGP as a theory ansatz may have been justiﬁed by the data
• to elevate QGP to the status of a discovered physical reality, need to
demonstrate uniqueness of the interpretations, embrace full gamut of the
phenomena, avoid ”conﬁrmation bias”.
49

Kent_2007

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (10)

Similar to Kent_2007

Similar to Kent_2007 (20)

Kent_2007