Post-QM2022:

Results from Beam Energy Scan
（ビームエネルギー走査、渦等の実験結果）
Takafumi Niida (Univ. of Tsukuba)

第39回Heavy Ion Cafe & 第35回Heavy Ion Pub合同研究会「ポストQM2022」@名古屋大学, 4/30/2024

e and baryon chemical potential, where we have a dilute gas of hadrons, which are predominantly pions,ractions are small corrections which can be systematically described in chiral perturbation theory and thetal knowledge of hadronic interactions. (b) At small values of the baryon number chemical potential anderatures (T & 130 MeV) from lattice QCD, and, (c), for small temperatures close to the nuclear matter
density from the extrapolation of well tested nuclear forces and experiments of nuclear fragmentation [37–Beam Energy Scan (BES)
2760

300

“Conjectured” QCD phase diagram

Temperature (MeV)250

200 s = 62.4 GeV
39
27

19.6

200

14.5

Quark-Gluon Plasma
11.5

B E S -I I

150
100

Vacuum0200

9.1

1st Orde 7.7
r Pha
se T
ran
sit
ion

Critical
Point

50
0

The Phases of QCD

H

s
a
G
n
o
r
d
a

400

600

Nuclear
Ma�er
800

1000

Main purposes of BES program:- Identify location of critical point (CP)- Search for the first-order phase transition- Search for onset/turn-oﬀ of QGP formation

C olor
S uperconductor
1200

1400

1600

Baryon Chemical Potential  B(MeV)

Lattice
QCDによると
A.
Bzdak
et
al.,
Phys.
Rep.
853
(2020)
1-87
schematic QCD phase diagram in the thermodynamic parameter space spanned by the temperature T and baryonic chemical potential-

sponding (center-of-mass) collision energy ranges for di↵erent accelerator facilities, especially the RHIC beam energy scan program,
A smooth crossover near μB~0 (μB<300 MeV)in the figure. Figure adapted from [40].
Pseudo-critical temperature at μB = 0: Tpc = 156.5 ± 1.5 MeV

et systemsal., Nature 443, 675 (2006)
r to experimentally explore the QCD phase diagram at finite net-baryon density, one needs Y.
to AokicreateBazavov
et al., PLB795 (2019) 15
net-baryon density in heavy ion collisions. Since baryon number is conserved, the onlyA.way
to increase!2

Outline

Run 20 and 21 completed successful
Cooling (LEReC) system, smooth &• (a bit on) Femtoscopy ←maybe covered by 関口さん

Events (M)• Fluctuations

10

BES-II

FXT

0.4

0.5

3.0

3.2

3.5

3.9

4.5

5.2

6.2

7.2

9.2

7.7

5

3
17.

11.

6
19.

14.
13.5
7

0
27.

BES-I

sNN (GeV)

3

102
10
0.1

• Vorticity and polarization• (a bit on) Dilepton ←maybe covered by 八野さん

0

10

4

39.

• Particle production

62.
54.4
4

Data taken by STAR BES-I&II + Fixed-Target program

0.2

0.3

0.6

0.7

µ (GeV)B

7 energies between 7.7 - 27 GeV (collider
12 energies between 3.0 - 13.7 GeV (FXT

RHIC Beam Energy Scan II completed＊Mostly based on STAR results but a few from other experiments＊Sorry for a mixture of English and JapaneseSTAR ov!3

Particle production at 3 GeV

Transverse Momentum Spectr

Talks by H. Liu (STAR) and B. Kimelman (STAR)

N. Xu et al., AAPPS Bull.31(2021)1

p

fit

Fig. 6 Heavy nuclei (dashed lines) and (multi-)hypernuclei (symbols) yields calculated in the HRG model [70, 71] for central
mid-rapidity as a function of center-of-mass energy. Also shown for comparison are the yields of ! hyperon from the sameenergy region of fixed target program in STAR is indicated as a yellow band. Model results from Ref. [71]

Ø Transpe
perseverance of the initial vorticit. T
keeps it from getting diluted [80].
Heinteraction rate experiments in highter at the upcoming facilitiesin
opensctunity to study relativistic effects ofangular momentum, and the magnecollter. This will guide theoretical develodtstar stability, see Ref. [53]) as well as the Y -N interaction driven EoS, with the strangeness degrees of freedom,in the hot and dense environment where the baryon
density could be very high. Simulations for neutron star
inner properties crucially depend on the EoS; see Ref.
[78] for the effect of Y -Y interactions and also Ref.
[79] for the hyperon effects including the possibility ofquark mixture. Furthermore, an additional benefit of the relativistic spin- and magneto-hydro-0.1 < ycm < 0.0 ´ 100
unique high baryon density environment is the enhanced
w/o feedproduction of multi-! hypernuclei as already suggested 5.4 Future experimental facilities fo-0.2 < ycm < -0.1
´ 10-1in Fig. 6.
matter
The future fixed target experiments, aimed for high The upcoming
facilities for studyin-2-0.3 < ysity
<
-0.2
´
10
baryon density matter, will collect data in heavy-ion collicm matter includes (a) the Nuclotro
sions around 2−8 GeV, which is within ideal energy range fAcility (NICA)
at the Joint Institute-0.4 < ycm < -0.3 ´ 10-3d" N
serving as the HNF, see Fig. 6. Hence,theseCollisions
future exper- (JINR), Dubna, Russia, (b)1the Comp
Au+Au
0-10%
iments could make tremendous contributions
towards ter(CBM) at Facility 2πpfor Antiprotos)) = 3 GeV! dp!
-0.5 < ycm < -0.4 ´ 10-4
measuring the yields of hypernuclei and their life-time. (FAIR), Darmstadt, Germany, (c) theThis would then provide valuable inputs to understanderator Research Complex (J-PARC), I
0-0.6 < ycm < -0.5 ´ 10-5
-0.1
<
y
<
0.0
´
10
ing the hyperon-nucleon (Y -N) interactionsin heavy-ion the CSR External-target Experimentcm
ρ = tancollisions and the inner dynamics of the compact stars.
sity heavy-ion-6 Accelerator Facility (H-1-0.7 < ycm < -0.6 ´ 10
-0.2 < ycm < -0.1 ´ 10
China. The interaction rates of the
5.3 Fluid vorticity of high baryon density matter -2
ments compared to existingand othFreeze-0.8 < ycm < -0.7 ´ 10-7
-0.3 < ycm < -0.2 ´ 10
Experiments at RHIC and LHC haveobserved that shownin Fig. 7. Note that all the neTn
the polarization of hyperons andvector mesons have on the energy
region where
the :ba:&'%-0.4 < ycm < -0.3 ´ 10-3
-0.9 < ycm < -0.8 ´ 10-8
a distinct energy dependence. Their values increase Below, we discuss briefly the salient
β$ :with decrease in collision energy.
Thephysics
experiments.
-0.5 < ycm< -0.4´ 10-4 rea-1.0 < ycm < -0.9 ´ 10-9
sons attributed for the observed energy dependence areatwofold. First, the baryon stopping
5.4.1 Model
NICA⃝JINRn :-0.6is< enhanced
ycm < -0.5 ´ and10-5 shear
Blast-Waveflow patterns in the beam direction emerge; second, At this new accelerator complex th
the shorter lifetime of the fluidtion, the plan is to provide accele-0.7phase< y < thereby-0.6 ´ 10-6allows

g

Ø Bla

el,
n

ed
ant

cm

-0.8 < ycm < -0.7 ´ 10-7

E. Schnedermann-0.9 < ycm < -0.8 ´ 10

-82022/4/7

Hui Liu, QM2022 @ Krakow, Poland

3 GeVでは、バリオンストッピングにより、バリオンが支配的な領域。
Quark Matter 2022 - Kraków, Poland-1.0 < ycm < -0.9 ´ 10-9
Blast-Wave Model

April 5, 2022
17 / 21
それに伴い、軽い原子核やハイパー核などがより多く生成されるようになる。

!4

Shift of the pion energy
Effectof
Coulomb
potential
Coulomb
Potential
inCentralCollisions
by the Coulomb
potential
Coulomb Potential in Central Collisions

Au+Au !!!
0-10% ce

Talks by S. Harabasz (HADES) and B. Kimelman (STAR)
Temperature (MeV)

HADES Collaboration, arXiv:2202.12750§

More accurate extrapolation to l§

120

Extracting the average value of
Coulomb potential energy

100

§

160
140

80
60

§

40
20
0

400

500

600

700
800
900
Baryochemical potential (MeV)

Improved formalism compare
previous works

Translating it to the fireball size
freeze-out → density → μB§

Method independent from SH§

Result in good agreement

Black data points, SHM fits:
Nature 561 no.7723, 321-330 (2018), also the black curve
PLB 764, 241-246 (2017)
PRC 73, 034905 (2006)
PRC 96, 044904 (2017)
PRC 76, 052203 (2007)
EPJA 52 no.6, 178 (2016)

Pions
are susceptible
to the Coulomb
potentialof stopped
duPions are susceptible
to theCoulomb potentialof stopped
baryons
due tobaryons
their sm
1,2
1,2
mass
mass
バリオンストッピングにより、正味電荷は正となり、クーロン場が生成される。

05.04.2022

ModelincludesBose-Einsteinnature
of
pions
and
an
e↵ective
potentクーロン場によって、正と負電荷粒子のスペクトルが変化する。
Model includes Bose-Einstein nature of pions and an e↵ective potential to accoun
momentum
distributionofstoppedprotons
momentum distribution of stopped protons
1

D. Cebra et al. [arXiv:1408.1369 [nucl-ex]]!5

Strangenessproduction
New results on identified hadron spectra in Be+Be an
Xu et al. AAPPS Bulletin(2021) 31:1

N. Xu et al., AAPPS Bull.31(2021)1

NA61/SHINE
p+p
Be+Be
Ar+Sc

PRELIMINARY+

K / π+ (y≈0)

Talks by A. Marcinek (NA61)

Page 7 of 16

see more in the talk

WORLD
p+p
Pb+Pb
Au+Au

0.2

0.1

0

AGS SPS

1

RHIC

102

LHC

104
sNN (GeV)√
Fig. 4 a Particle yield ratios of kaons to pions as a function of sNN . Thermal fits are also shown as bands in the plot. The dot dashed line represents
the net-baryon density at the chemical freeze-out. K + /π + (circles) trace the baryon density at the chemical freeze-out well, while K − /π − (triangles)√√
increase smoothly as a function of sNN . b Particle yield ratios of φ-meson to kaon (φ/K − ) as a function of sNN . At energy below 8 GeV, the GCE fit
no longer works, and the strangeness CE takes overK+/pi+ “horn” was considered as a possible signature of phase transition. But with BES-I data,
it is rather smooth transition with energy. No peak in smaller systems (Ar+Sc, Be+Be) by NA61/SHINE.
+とΛのassociate production (N+N->N+Λ+K+)が支配的、＊バリオン密度が√sNN~7 GeVで最大、K
net-baryon density with collision energy and shows a conservation laws do impose restriction on particle pro-smooth increasing trend.
ということから7 GeV付近のピークは大体説明できる。

Through these measurements we have the knowledge ofregions in collision energy where the maximal net-baryon

duction if the available phase space is reduced. Hence,
the relativistic statistical thermodynamics provides two
choices for the formalisms: a GCE and a CE approaches

!6

sNN

Strangeness production vsSTAR Preliminary

0
Ks

−1

10

y=0

Λ
−2

10

Ξ

−3

10

STAR Preliminary

−4

10

STAR

E895

E891

NA57

WA97

NA49

PHENIX

HADES

−5

10

1

3

2

10

10

sthr ~ 2.55 GeV
sthr ~ 2.55 GeV
sthr ~ 3.25 GeVsNN(GeV)

24
22
20
18
16
14
12
10
8
6
4
2
0

Enhancement at intermediate pT at √sNN >= 19.6
0-> hadronization
through
The lower
production
yieldquarkof Kcoalescence, Λ, Ξ− at 3 GeV:S

Talk by A. Sahoo (STAR)

J. Cleymans, arX
Phys. Rev. C 102
Phys. Rev. Lett.

Au+Au Collisions at RHIC

24
0Strange Hadron Ratios Λ/KS

part

STAR, PRC102, 034909 (2020)

Data compilation: C. Blume Prog.Part.Nucl.Phys. 66 (2011) 834-879
HADES: Phys.Lett.B 793 (2019) 457-463, 2019

Baryon-to-meson ratio(top 0-5% central)STAR Preliminary

20

sNN = 3 GeV sNN
NN (GeV)

16(-0.5<y<0)sNN =3GeV(|y| ≤≤ 0.5)
0.5)
(|y|

7.7

(-0.5<y<0)

Thermal m

11.5

N(Λ)
∝
exp
N(KS0)

19.6

12

27
39
200

8

σS = μS/μB

4
0
0

1

2

3

4

5

Baryon ch
driven?

Transverse Momentum p (GeV/c)
T

Fast increase with pT at 3 GeV• At0high1energies,
2
3the ratios
45increase verse p!7
3 GeV/c and then fall for higher pBaryon-to-meson ratio
STAR, PRC102, 034909 (2020)

Enhancement at intermediate pT at √sNN >= 19.6-> hadronization through quark coalescence

Talk by M. Puccio (ALICE)
ALICE, arXiv:2112.08156

Similar enhancement in charm sector-> charm recombination?
!8

Talk by Hui Liu (Thu T16)
ineticfreeze outfreeze-outof light nuclei
Kinetic
parameters

Discussions – Simultaneous Fitting of !, #, $ields of proton & light nuclei measured at 3 GeV, well
+ Au Collisionskinetic
at Mid-rapidity
Au + Au Collisions at Mid-rapidity
escribed by models, effectiveAuaverage
freeze outØ At 3 GeV Au+Au collisions, the freeze-out
arameters extracted using
cylindrical blast waveCentral
fits
Peripheral
Centralparameters (T Peripheral, β ) show different trend
/01

10-1
proton-2

10deuteron3

triton4

HeHe

19.6 GeV

10200 GeV

10

1

100

10-1

STAR Preliminary

-2
1050

p: 0.4< p < 1.0
GeV/c
Au+Au
Collisions
T
K: 0.4 < p < 1.0 GeV/cTs
p: 0.6 <NN
p =< 3
1.6GeV
GeV/cp, K, p Preliminary(3 GeV)STAR

1y!"#$%! = −1.045

-0.5

0

10-1
SMASH + Coal. (p,d,t)
JAM (p)
UrQMD (p)

-2

10

-1

-0.2
0.5
0 0.4-1-0.50.6
Collective Velocity áb ñ (c)Particle
RapidityT

2022/4/7

7.7 GeV

200 GeV100

Ø At high energy collisions, the trends offreeze-out parameters(T/01 , β2 ) for ( andSTAR Preliminary, follow the 5, <, ( within the uncertaintyT-1

Gray: π, K, p (BES-I)(MeV)

20-40% 7.7 GeV

kinTemperaturedN/dy T

0101

10-20%

150

kin

10
101

10

compared
150 to that of higher energy
collisions

p, K, p (BES-I)

Temperature T

0-10%

10

2

dN/dy

10

2

(MeV)

2

2

50

p

d 3 GeVpd SMASH: 0-10%

p, d fit: 0.6 < p /A < 1.6 GeV/c
T

0

0.2

0.4

0.6

Collective
Velocity〈β 〉 (c)L. Adamczyk et al. [STAR Collaboration]
Phys.Rev.C 96(2017) 4, 044904
T
B.I. Abelev et al. [STAR Collaboration] Phys.Rev.C 79 (2009) 034909

Hui Liu, QM2022 @ Krakow, Poland

n

19
p

Different trend of kinetic freeze-out temperature (Tkin) and and radialflow velocity (β) at 3 GeVp
Deuteron freeze out at higher effective temperatures and(applicability of blast-wave model at this lower energy?)

aller velocities compared to that of protons at √s NN = 3 GeV

Effective T kin(d) > T kin (p)３GeVにおけるTkinは、7.7-200 GeVと比較して低い。

STAR overview, P. Tribedy, QM 2022, Krakow, Poland

22

Tkin(d) > Tkin(p) : pよりもdの方が早くfreeze-outする?
!9

*0
Probing hadronic-phase lifetime by K /K

production

924

4 fm/cRegeneration gain

K0

Kinetic Freezeout

K 0

Talk by Aswini K Sahoo (Thu T14-I)
Poster by Yingjie Zhou (Fri T11_2)0

IV.

*0

K*
/K
Ratio
Talk by A. Sahoo (STAR)
Hadronic-Phase Lifetime

Hadroni

K to K ratio with 8BES data indicate*0New
re-scattering loss due to shorter lifetime of K New

HadronSUMMARY
0.45

1

Particle Ratio

Chemical Freezeout-B x
In summary,
we report the systematic measurementsofK
y= A1eAu+Au 39 GeV
0.4 yields andK , (1020) and ⌅ production
the/K,
A1=0.35 ± 0.07, B1=0.084 ± 0.039
p*0
GeV0.0772
with the/⌅ ratios in Au+Au collisions at sNN =r23/NDF=
K
/K
0.35
K
STAR experiment at RHIC. The measured /K
ratio 0.9892
is sigProbability=q/K
nificantly larger than the statistical
0.3 model prediction based
Re-scattering
loss Ensemble in the 0–10% central collion Grand Canonical
0.25
0 Both thesions.
resultsof/K(rc ⇠ 2.7 fm) and /⌅KK(rc ⇠ 4.2 fm) ratios favor the 0.2
Canonical Ensemble model
ALICE
for strangeness production in such collisions. Transport modSTAR:
0.15 could reasonably describe
ALICE: Phys.Lett.B 802 (2020) 135225
0
0
-Δt/τ
els, including the resonance decays,
●
(K*
/K)
=
(K*
/K)
×
e
STAR: Phys. Rev. C, 84:034909, (2011)
kin
chem
and
the increasing
trend -Δt/τ
our measured /K ratio at 3 GeV
where, Δt = Hadronic phase lifetimeALI(
0.1
0
0
➔
●
(K*results/K)kin =(K*y=this/K)eerrorsare quadratic sum of 0
0.122
±×
0.003
chem
of /⌅ at lower energies. The new
from
paper
0
STA
0
0
0
+
The K* /K ratio for A+Aτcollisions
areoffor= Lifetime
K*most central
2
Here
K*
denotes
K*
+
K*
and
K
denotesK+K
r /NDF= 0.8092
statitical● and0systematic
errors -Δt/τ STAR.
STAR
Preliminary
where, Δt production= Hadronic( tkin– tchem )STAR
Preliminary
0.05strangenesssuggest a significant change in theforphase lifetime
0(K* /K)kin = (K* /K)chem×ep Unaffected
Probability=
0.5427*0*0
短寿命の共鳴粒子は、hadronic
phase lifetimeに敏感な量。 ● ● (K0
ZhangbsNN < 5 GeV, providing new insights
towards
the under/K)
<
(K
/K)
τ
=
Lifetime
of
K*
Here
we
can
take
(2004)
where,central
Δt = Hadronic phase
lifetime
peripheral
0 et al..Z. Phys. C, 61:1–18,1994 (e+e)
H. Albrecht
002
3
4 den5
6 Phys.
7CC66
861901STAR.
Rev.
66(2002)(2002)
S.Singh●standing of the QCD medium
properties
athighbaryon
(K*
/K)
≈
(K*
/K)
STAR.
Phys.
Rev.
61901
Hadronic
phase
lifetimeat0kin τ = Lifetime
AAof K*
Yi-Jin Pei.rescattering
Z. Phys. C,72:39–46,1996(e+e)
05, 155
1/3STAR.
(減少)とregeneration(増加)の兼ね合い。
*0
*0
Phys.
Rev.
C.71.064902(2005)(p+p, Au+Au)
Zhangbu
Xu.J.
Phys.
G
30,
S325--S334,
●
0
0
(K
/K)
<
(K
/K)
(dN /dd) STAR.
●sity.
W Hofmann.
Ann. Rev.
(K*
/K)
≈
(K*
/K)
Here
we Nucl.
can Part.Sci.,
take 38:279–322
RHIC
seems
to
be
smaller
Phys.
Rev.
C,
78:044906(2008)(d+Au,Au+Au)
centralpp/ee-referen(2004)
STA
chem
pp
ch
1988 (e+e)
45 fm/cV. ACKNOWLEDGEMENT
00
Zha
S.Singha.etal.Int.J.Mod.Phys.E
24 (2015)
STAR.
Phys. Rev. C, 84:034909(2011) (C+C,Si+Si)than LHC
(K*
/K)
≈
(K*
/K)
●
中心衝突におけるrescattering
loss
(more
statistics
isHere we can takeAA (e+e)
K. Abe et al: .Phys.Rev. kin
D, 59:052001, 1999
(200●
05, 1550041
STAR.
Phys. Rev. C, 102(3):034909 (2020) (Au+Au)(φ/K):
independentofcentralit
000 al. Z. Phys. C, 0
S.S
M.Can
Aguilar-Benitez
et50:405–426,1991
(K*
/K)
≈
(K*
/K)
neededfor
confirmation)
be
used
to
estimate
mediumlifetime
(K*
/K)
≈
(K*
/K)
ALICE.
Phys.
Rev.
C.91.024609(2015)(Pb+Pb)kin
AAMedium lifetime
05,
chem
pp
LHCでは、regenerationの影響が大きい
and/orhadronic
phaseが長い(p+p)
0
0ALICE. Phys. Rev. C.95.064606 (2017) (Pb+Pb)
We would like to thank D.
K.Drijard
RedlichandJ.
Steinheimer
for
(K*
/K)
≈
(K*
/K)pp
Favorsdominant
hadronic
re-scachem
et al. Z. Phys. C, 9:293, 1981 (p+p)
ALICE. Phys. Lett. B, 802:135225 (2020) (Pb+Pb)
fruitful discussions. We thankthe et
RHIC
Operations
Group
QM
2022,
A.76(5):245,(2016)
K. Sahoo
T. Akesson
al. Nucl.
Phys. B, 203:27,
1983 (p+p)
21
ALICE. Eur.
Phys.
J. C,
(p+Pb)
incentralA+A
collisions
NA49.
Phys. Rev.
C.84.064909
and RCF at BNL, the NERSC
Center
at LBNL,
and (2011),
the Open!10
constrain strangeness correlation length & hadronic phase lifetime
ision
●

●

*0
Probing
hadronic-phase
lifetime
by
K
/K
⇤
0
Talk
by
AswiniK
Sahoo(Thu
T14-I)
production
SystemPoster
sizebydependence
of
K
(892)
to
chargedkaon
ratio
Yingjie Zhou (Fri T11_2)
Motivation〈K*(892) 〉/ 〈K 〉

*0

Hadronic-Phase Lifetime

Talk by A. Sahoo (STAR)
Talk by M. Lewicki (HADES)〈K*(892) 〉/ 〈K 〉

K

0

+/-

4 fm/c0NA49〈K*(892) 〉

0

-

NA49

-

NA49 (p+p: NA61)/ 〈K 〉

NA49 (p+p: NA61)

I NA61/SHINE K +/ : EPJC 77, 671, 2017
I NA61/SHINE K ⇤ (892)0 : EPJ C80, 5, 460, 2020; arXiv:2

0.6

0.45

+

NA61/SHINE: 〈K*(892) 〉/ 〈K 〉
0+
〈K*(892) 〉/ 〈K 〉

0

Kinetic Freezeout

I Results from:
1 ratio with 8
K
to
K
BES
data
indicate
K*0 I NA49 K ⇤ : PR C84, 064909, 2011
Motivation
New
924
⇤
0
re-scattering
loss
due tokaonshorter
lifetime of K I NA49 K +/ : EPJC 68, 1, 2010; PRL 94, 052301, 2005; P
0.8
Regeneration
gain
System size dependence
of
K
(892)
to
chargedratio
IV. SUMMARY00NA61/SHINE: 〈K*(892) 〉/ 〈K 〉

0

+

0

-

1

+

NA49

-

NA49

NA49 (p+p: NA61)

NA49 (p+p: NA61)

Particle Ratio

0

0

3

2

0

+

0

-

〈K*(892)0〉/ 〈K+/-〉〈K*(892)0〉/ 〈K+/-〉

Chemical Freezeout

0

+/-

-B x
〉/ 〈K 〉 the systematic
In summary,
we 〈K*(892)reportmeasurementsof
K NA61/SHINE:
I1
y= A1efrom:
Results
NA61/SHINE: 〈K*(892) 〉/ 〈K 〉
Au+Au 39 GeV
0.4
I Time between chemical and kinetic freeze-ou
0.4⇤
K , (1020)
and⌅production
yieldsandthe/K,〈K*(892) 〉/ 〈K 〉
I
A1=0.35± 0.07,B=0.084
±
0.039
NA49
K
:
PR
C84,
064909,2011
1p〈K*(892) 〉/ 〈K 〉
0.8
*0
+/
IGeV
with
the
/⌅ ratios in Au+Au collisions at sNN =r23/NDF=
NA49
K
:
EPJC
68,
1,
2010;
PRL
94,
2005;
PR@
C66,
054902,
2002
K/K052301,
0.0772forp+p
158
GeV/c:
0.35
0.2
KI NA61/SHINE
K +/ : EPJC 77, 671, 2017STAR
experiment
at
RHIC.
The
measured
/K
ratio
is
sigProbability=
0.98920.6⇤ (892)0 /K +
I
⇤
0
I
5.3
fm/c
for
K
NA61/SHINE
nificantly larger than the statistical
based K (892) : EPJ C80, q5,/K460, 2020; arXiv:2112.09506
0.3 model0 prediction⇤ (892)0 /K
Iloss Ensemble in the 0–10%
4.6
fm/c
for
K
3
on Grand Canonicalcentralcolli2
0.4 Re-scattering
I 1Time between
101010
chemicalandkinetic freeze-outs (Lorentz inv.)
0.25
0 Both thesions.
results of /K (rc ⇠ 2.7 fm) and /⌅
〈N 〉
⇤
K
W
K
K
for p+p @158 GeV/c:
0.2(assuming no regeneration processes: K Pb+Pb(rc ⇠ 4.2 fm) ratios favor the 0.2
Canonical Ensemble
model
⇤
0
+
I
5.3
fm/c
for
K
(892)
/K
for strangeness production in such collisions. Transport mod0
0.15 could reasonably⇤ (892)0 /K Phys.Lett.B 802 (2020) 135225
NA61/SHINE〈K*(892)〉/ 〈K 〉, p+pALICE:I
els,
includingtheresonance
decays,describe
4.6
fm/c
for
K
1
10
10
1
10
STAR: Phys. Rev. C, 84:034909, (2011)I ⇤ t at SPS >⇤ t at RHIC
(at
corresponding
centr〈K*(892) 〉/ 〈K 〉, p+p
andtheincreasingtrend
our measured /K ratio〈Natt〉 3 GeV
0.1
0
0
-Δt/τ
W
K
K➔ errors
●
(K*
/K)
=
(K*
/K)
×
e
⌧ ) quadratic sum of
are
y=
0.122
±
0.003
(assumingnoregeneration
processes:=e0.8kin from this chemof /⌅ at lower energies. The new resultspaper
PR C71,2005
KSTAR,
K 064902,
Pb+Pb
p+p
2
r /NDF= 0.8092
statitical and systematic errors
STAR
Preliminary
where, Δt production= Hadronic( tkin– tchem )STAR
Preliminary
0.05strangenesssuggest a significant change in theforphase lifetimep! regeneration e↵ects may be significant at hig
Probability= 0.5427
NA61/SHINE〈K*(892) 〉/ 〈K 〉, p+p
短寿命の共鳴粒子は、hadronic
phase
lifetimeに敏感な量。
0
Unaffected
0.6
1sNN < 5 GeV, providing new insights towards
the underτ=LifetimeofK*
0
I 3t at SPS4 > t at5RHIC (atcorresponding
centrality)〈K*(892) 〉/ 〈K 〉, p+p
2
6
7
8
●
I
standing of the QCD medium properties at high baryon denSTAR. Phys. Rev. C 66 (2002) Regeneration
61901
e↵ects
may
exist
also
at
SPS
Hadronic
phase
lifetime
at
1/3
ただし、rescattering(減少)とregeneration(増加)の兼ね合い。
0.4 STAR, PR C71, 064902,
0.8
Zhangbu Xu.J. Phys. G 30, S325--S334,
2005
(dN
/d
d
)
●
sity.
Here we can take
RHIC
seemslimit
to beofsmaller(2004)!
obtained
t
is
lower
time
betweenfch
45 fm/cV. ACKNOWLEDGEMENT
0 ! regeneration
0
S.Singha.etal.Int.J.Mod.Phys.E
24 at(2015)e↵ectsmaybesignificant
higherenergies
(K*
/K)
≈
(K*
/K)
中心衝突におけるrescatteringloss
than LHC (more statistics is
0.6
kin
AA
0.2
05, 1550041
00needed for confirmation)
Can
be
used
to
estimate
mediumlifetime
(K*
/K)
≈
(K*
/K)pp e↵ects
I
Regeneration
may
exist
also
at
SPS
Medium lifetimechem
Δt
RHIC<ΔtLHC: LHCでhadronic phaseが長いことを示唆？
0.4
We would like to thank K. Redlich and 0J. Steinheimer for! obtained
t is lower
limit
of time between freeze-outs
5
10
15
20
fruitful discussions. We thank the- RHIC
Operations
Group
QM 2022, A. K. Sahoo
21
ΔtSPS>Δt
RHIC: RHICにおけるregenerationの影響？
0.2
sNN (GeV)
and RCF at BNL, the NERSC Center at LBNL, and the Open!11
constrain strangeness correlation length & hadronic phase lifetime
ision
0

+

0

-

Skewness (S) → asymmetry

Kurtosis (κ) → sharpness

CP search with fluctuations
Talk by T. Nonaka

Cumulants of conserved charg• Measure event-by-event distributions of netWhy do we want to study fluctuations of conserved charges?
baryon, net-charge, and net-strangeness number• Critical pointでは、（無限に大きな系では）相関長が発散するで定量化
n• • 保存量の揺らぎ相関長ξに敏感で、揺らぎはキュムラントC
to the correlation
length :• Cumulants
have additivity
Cumulant ↔ Central moment (1) Sensitive

proportional to thesystemvolumeM. Stephanov, PRL102.032301 (2009)
M. Asakawa et al., PRL103.262301(2009)•
M. Asakawa, S. Ejiri, and M. Kitazawa, PRL103262301(2009)
net-baryonは測定できないので、net-protonを用いる• Needsusceptibilities
to consider various experimental effects.
•(2)Comparison
with2022/4/9, QM2022@Krakow
T. Nonaka "Fluctuations of Conserved Charges"

M. A. Stephanov, PRL102.032301(2009), PRL107.052301(2011)
体積効果をキャンセルするために、キュムラント比が測定量
Raw net-proton multiplicity distribution

2022/4/9, QM2022@Krakow

4

T. Nonaka "Fluctuations ofConserved Charges"
STAR, PRL126.092301(2021),
PRC104.024902(2021)!12

Net-proton C4/C2

FXT from HADES and STAR

Talks by T. Nonaka, Yu Zhang (STAR)

from HADES and STAR
• No clear enhancement is observed for 2.4 and
3.0 GeV data from HADES and STAR.

•• Negative value at 3GeV is reproduced by
No clearenhancementisobserved
for
2.4
and
UrQMD,
which
incorporates
baryonnumber
HADESの2.4 GeV、STARの3 GeVのC4/C2は、3.0 GeVconservation.
data from HADES and STAR.
ゼロもしくは負の値になる

2.4 GeV

•

•
The
data
implies
that
the
QCD
criticalregion→baryonconservation(UrQMD)で説明できる
Negative value at 3GeV is reproduced bycould only exist at energies > 3GeV.

UrQMD, which incorporates baryon number
CPから予測されるピーク構造は、3 GeV以上にありそう
conservation.
→ BES-IIの高統計に期待

HADES,
PRC102.024914(2020)
STAR, arXiv:2112.00240
STAR,
arXiv:2112.00240
HADES,
PRC102.024914 (2020)2022/4/9, QM2022@Krakow

•
The
data
implies
that
the
QCD
criticalregionth
Apr. 5 , 4:30pm, Yu Zhang
could only exist at energies > 3GeV.

T. Nonaka "Fluctuations of Conserved Charges"

44

!13

lantCrossover search

Talk by T. Nonaka,
Talk by H.-S. Ko (STAR)

LQCD predicts C6/C2<0 and C5/C1<0

Net-baryon- In 200 GeV Au+Au, C6/C2 changes the sign to be negative whenNet-proton HotQCD, Phys. Rev. D 101, 074502 (2020)

going from peripheral to central collisions- Isobar results follow the trend of multiplicity dependence from Au+Au
and p+p at 200 GeV

High-order net-proton cumulant ratio comparison
Net-proton
C6/C2 for crossover2 search
1.2
C4/C2 (STAR Preliminary)

C5/C1 (STAR Preliminary)2%|y| < 0.5, 0.4 < p < 2.0 GeV/c
T

Data:

•

HRG GCEp+p
Lattice−4 suggest
Could
a smooth crossover
Au+Au
Pythia (8.2)

transition at top RHIC energy.
10−2

Au+Au:

40

0.4

0.2

0

0-

0%

40

-5

0%

50

-6

0%

60

-7

0%

-8

70

Cumulant Ratio

STAR, PRL127.262301 (2021)
1● Transition
from QGP to hadronic matteris smooth crossover at μB ≈ 0.
0
• C6/C2 values are progressively
0.8
6th order:
first principle lattice QCD
negative from peripheral to central
calculation predicts C6/C2 < 0
Au+Au:
Au+Au:
0.6
collisions
at 200 GeV, which is−2
6 consistent
Ko | QM2022
Zr⊕Ru:
Zr⊕Ru:
with LQCD calculations.

C6/C2 (STAR Preliminary)

100

STAR, Phys. Rev. C 104, 024902 (2021)
STAR, Phys. Rev. Lett. 127, 262301 (2021)

1000

10

100

Zr⊕Ru:

Zr+Zr
Ru+Ru

−4
sNN = 200 GeV Net-proton
−6

1000

10

100

1000

Charged Particle Multiplicity

STAR, PRL127.262301(2021)(Efficiency uncorrected x-axis)

Poster by Ashish Pandav (S1 T07_1)!14Model A: Correlated p and n (np=nn).

Cumulant
Ratiosandp-dCorrelation2

deuteron-proton
λ = Bcorrelationnλ = B n n1d2

Deuteron| y | < 0.5
1
d: 0.4 < p /2 < 2.0 (GeV/c)T
p: 0.4 < p < 2.0 (GeV/c)
0.6
T
Monotonic
0.8 Model A:2
1.2
10PreliminarySTAR
1.02 STAR
Preliminary
Au+Au Collisions100 σd

on with Net-proton(3)

Ratio C 4 / C 2

d1

1.2 STAR Preliminary
Au+Au Collisions

0.8

T

1.02

11

(1) κdσ2dρ(np, nd) =M

Au+Au Collisions

T

100 σ2d

STAR10Preliminary

Thermal-FIST
GCE
CE

(3)

Pearson’s
Talk by D.negative
Mallick -0.05(STAR)p In
n panel(4),

100

0.04

0.98
Thermal-FIST
UrQMD+Coalescence
GCE
CE
0.96
50 50100 100200
5
10200 205

10 10 20 20
Collision Energy s NN (GeV)

Thermal-FIST
GCE
CE

50
10

Model
B: ρ < 00% - 5%(1,1)
C (p,d)(4) σ σd70% - 80%
Poissondescribe the cumulant ratios for lower
reproduce
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reproduce collision energy dependence.

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p, n Independentp, n Independent

20
100

50
200

0.95

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lowering
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Quark
Kraków,
April
2022
thermalmodel
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thermal modelseems
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Coalescence100
20 200 5 50 10

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Pearson’s
With lowering
the sNN, anti-correlatio
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becomesstronger.
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1

Md

UrQMD+Coalescence

ratios in proton
0-5%
centrality,show
coefficientand deute
TalkCumulant
bysuggests,
S. Kundu(ALICE)
monotonic
dependence-0.1
on sacross
1.05
NN .
numberare anti-correlatedall
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-0.15
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NN

−0.02

100

−0.02
UrQMD+Coalescence also reproduces

UrQMD+Coalescence also reproduces
the
trend
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withthe cumulant
ratios.

200

Neither correlated nor independent
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forfrom
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toy model
Z. Fecková
et. al,:neutron
PRC 93, 054906(2016) from
reproduce
the data.
toy model
Z. Fecková
et. al,: PRC 93, 0549
Quark Matter, Kraków, April 2022 (2016) reproduce the data.
15/17

Collision Energy s NN (GeV)

Collision Energy s NN (GeV)Black bars: statistical uncertainties
Grey caps: systematic uncertainties
Black bars: statistical uncertainties

Grey caps: systematic uncertainties

ws monotonic Blackenergydependence
in uncertainties
contrast to protons.
bars:
statistical
Grey caps: systematic uncertainties

Debasish Mallick
Monotonic energy dependence
Debasish
Mallick
be affecting
fluctuations?
ofthe
deuteron(B=2) fluctuations

re investigation ongoing. Theoretical inputs are also needed.

Matter, Kraków, April 2022

0.95

p
10
STAR Preliminary

2(2) Sdσd70% - 80%
σpPoisson
σdDeuteronSTAR
Preliminary| y | < 0.5
d: 0.4 < p /2 < 2.0 (GeV/c)T
p: 0.4 < p < 2.0 (GeV/c)

0% - 5%
1
70% - 80%
Poisson
UrQMD+Coalescence

0.8
0.98

STAR Preliminary

0% -−5%⟨(np − ⟨np⟩)(nd ⟨nd⟩)⟩

ρ > 100

Deuteron, | y | < 0.5
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0.6

0.6
0.96
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in both STAR BES and ALICE- p andQuark
Matter, Kraków,
2022- Data favors coalescence with independent p and n fluctuations

15

16/17

!15

femtoscopic

deuteron-proton
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mtoscopy in Au+Au Collisions
at 3 GeV
Proton-Deuteron
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1.5
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Au+Au

STAR Preliminary
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1.5

1.5

0.4 < p < 2.0 GeV/c 1.5

STAR Preliminary Au+Au Collisions

T

Femtoscopy&
correlationofnuclei@ s = 3 GeV
C(k*)
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11

1

0.5
0.5
0.5

10-20%
00
200 0 000
k* (MeV/c)

Ratio C 4 / C 2-0.5<30GeV@s<NNy=
Au+Au
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DeuteronCF, | y | < 0.5
0.8 < p < 4.0 (GeV/c)
1

11

NN

1

T

1

T

STAR Preliminary
Talk by Ke Mi (Thu T07-III) 1
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1

1

n

Lednicky Modelnr = 2.5 fm
r =0%
3 fm- 5%0.5
r =70%
4 fm - 80%
0.5
r = 5 fm

p CF
p-d

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0.5 measurements of d-d
First
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0.8 p-d CF femtoscopic
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40-60%
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at
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100
100

00
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0.6
100

0

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100
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STAR Preliminary
Ratio C 4 / C 2

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1.5

Deuteron CF

100

Talk by K. Mi (STAR)& P. Tribedy
1.2 (STAR)
STAR Preliminary010-20%200
200 0

UrQMD+Coalescencep

Lednicky Modelr = 2.5 fm
Lednicky
Model

p

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collisions@ sNN = 3 GeVSTAR Pre
100
Au+Au
Collisions
5
10
20
50
200
STAR
Pre
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Collision
Ener
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at
STAR
|
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|
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correlations
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atPreliminary
small k*range
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d: 0.4 < p T /2 < 2.0 (GeV/c)
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1
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1
1
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e size with r = 3-4 fm is consistent
withdata source
Ø A
spherical
size with&r Lyuboshitz= 3-4 fm is- consistent
with datawith coalescenceØAspherical
source
size
with
r
=
3-4
fm
is
consistentdata−0.02 Rwith
1.LednickýR,LyuboshitzV.Sov.J.Nucl.Phys.35:770(1982)
1.Lednický,LyuboshitzV.Sov.J.Nucl.Phys.35:770(1982)
C(k*)

C(k*)

σ pσ d

100

0

(1,1)
C (p,d)200 000% - 5%2.J. Arvieux, Nucl. Phys. A 221 (1974) 253–268
2.J. Arvieux, Nucl. Phys. A 221 (1974) 253–268
1.LednickýR,LyuboshitzV.Sov.J.Nucl.Phys.35:770(1982)
0.5
0.5
0.5
0.4
< p- 80%< 2.0 GeV/c 0.5
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Tk Matter 2022- Krakow, Poland - Ke Mi
13 Krakow, Poland - Ke 2.J.
Quark Matter 2022Mi Arvieux, Nucl. Phys. A 221 (1974) 253–26813
T-0.5 < y < 0-0.5 < y < 0
SMASH(Coal.) + CRAB
UrQMD+Coalescence
Coalescence
Quark Matter 2022- Krakow, Poland - Ke Mi
13
−0.06

0-10%

0

0

100

200

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40-60%00k* (MeV/c)

100

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5

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50

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100
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Global lambda polarization

Vorticity and polarization
Precision new FXT (3 GeV) and BES-II

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V

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field
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Adamstrend(STAR)(19.6 GeV) results follow
globalP [%]STAR Au+Au 20%-50%

STAR Preliminary Nature548.62 (2017)
Orbital angularFXT
momentum

Λ

Λ

3 GeV
Z.-T. Liang and
X.-N. Wang, PRL94, 102301 (2005) PRC76.024915 (2007)

ΛΛ

PRC98.014910 (2018)

ΛΛ

PRC104.L061901 (2021)

Λ

(Λ)

L=r⇥
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wikipedia_
T19.6 GeV (Λ + Λ)

AMPT, Λprimary

primary+feed-down

2(eB ⇠ m⇡ (⌧ ⇠ 0.2 fm))<latexit sha1_base64="M57Jw2SWFxvE8peHZsYuobPdjBA=">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</latexit>（ΞやΩの偏極測定もされている）

α Λ = -α =0.732

UrQMD+vHLLE, Λ
primary
primary+feed-down

D. Kharzeev, L. McLerran, and H. Warringa,10

Nucl. Phys. A803, 227 (2008)
初期の軌道角運動量→反応平面垂直方向に粒子のスピンが偏極
L. McLerran and V. Skokov, Nucl. Phys. A929, 184 (2014)

T.-Niida,
SQM2021
weak
decayするΛハイペロンを用いた測定

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Λ

HADES prelim. SQM2021
Λ Au+Au 10-40%
Λ Ag+Ag 10-40%

FXT field
Strong magnetic
0Λ

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7.2 GeV(Λ)Λ

PΛ [%]LB

PH [%]

Poster by K. Okubo (STAR)102

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3

11 10

T s

NN

[GeV]

3

MoreNopreciseresults
from BES-IIatarecomingsystemdependence
fixedcentrality orSTAR overview, P. Tribedy, Q!17

Talk by Joey Adams (Thu T02-II)a polarization
Global polarization
isobarcollisions
Posters by Kosukein
Okubo(Wed T02) & Xingrui
Gou (Wed T02)

by Joey Adams (Thu T02-II)
2) & Xingrui Gou (Wed T02)

d
with
high
statistics
T (3 GeV) and BES-II
tollow√sNN =
200
GeV
the global trendminaryage

STAR Au+Au 20%-50%

vs.

Nature548.62 (2017)

P ||
Λ

B
Λ

PRC76.024915 (2007)

ΛΛ

PRC98.014910 (2018)

ΛΛ

PRC104.L061901 (2021)

ΛSTAR prelim.
Λ+Λ

Λ

2

PΛ [%]

P ¯ || B

Various predictions tested with high statistics
isobar & Au+Au data at √sNN = 200 GeV

Λ

−1

vs.

Pb+Pb 15-50%

Zr+Zr

PΛ [%])vs.
Λ

α Λ = -α =0.732

down

102

Au+Au

3

10

sNN

Λ

Ru+Ru
[GeV]

PIsobarでは、初期の磁場
P || B(B2)が10-15%異なるので¯ || BΛ1

1

sNN = 200 GeV
Centrality
20-50%

しているが、その関係は見られるか？ PΛAu > PΛRu/Zr−1_50
Centrality
[%]
Λ
Ru+Ru
Λ
Zr+Zr
45

Au+Au

vs.

2

1

0

S. Shi et al., PLB788 (2019) 409
S. Alzhrani et al., arXiv:2203.15718

Ru+Ru
Zr+Zr
→ Λとanit-Λに有意な差はなさそう。
Average−1
20

Panti-Λ>PΛ の関係は見られるか？
vs.

小さい衝突系のほうが大きな偏極とモデルは予想

025 30 35 40
220 STAR
Preliminary

Ru+Ru

age

down

STAR Preliminary
Ru+Ru
Zr+Zr
Au+Au

AverageΛ

HADES prelim. SQM2021
Λ Au+Au 10-40%
Λ Ag+Ag 10-40%

20

ALICE PRC101.044611 (2020)
Λ

1

Talk by J. Adams (STAR)
Poster by X. Gou (STAR)＆ 衝突系の違いは見られない。O+O?

0vs.

sNN = 200 GeV
Centrality
20-50%
25

30

35

−1

40

45

50

Au+Au

Ru+Ru

Centrality [%]en in 200 GeV
collisions
dependence
at fixed
centrality
or
seen
in
200
GeV
collisions
197
96
96 B-field63driven splitting
16
Au > Ru, Zr > Cu > O
44 9
40
STAR overview, P. Tribedy, QM 2022, Krakow, Poland<latexit sha1_base64="trLnscLCc1++XrOnREFaD49IVEQ=">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</latexit>

9!18

T out and expand
theh four-velocity u, thereb
1⌫b⇢bLEwith:
'
exp
(x)
P
+
the (7)
⌫
ZLE
Z
h
11
@ u⌫ (x)⌫ (x)d⌃⇢bLE 'exp
Pb⌫µ+(y)(y x) Tbµ
ZLETby J. Adams
Talk(STAR)
Z⌃
1 by T. Niida (STAR) bµ
Poster@ u⌫ (x)gradients,d⌃µ (y)(yIncluding temperature
which x)are TnoT
hypersurface at x, in the⌃ Taylor expansion
Flowによって、ビーム軸を回転軸とするような渦が生まれ、
make the temperature
whole approximation
Then
Including
gradients,worse.
which arenoter of fact, in at
all x,
theinpreviously
expr
hypersurface
the Taylorderived
expansion
それが偏極に繋がる。
can replace
the gradientsof worse.
with theThen
gra
makethe wholeapproximation
multiplied
1/Tthewhere Tdecderived
is the deco
dec ,previously
terof fact, byin allexpr
perature.
Particularly,
the ofspin polarizationcanreplacethe gradientswith the gra- Au+Au 200 GeV同様、isobarでもv2-drivenな偏極を観測
emitted spinis:multiplied
by1/2
1/Tbaryon
dec , where Tdec is the deco
- ２次同様、３次平面に対する依存性も観測！
perature.
Particularly, the spin polarizationµ
SILE (p) =emittedspin 1/2 baryon is:hR→v3-drivenな渦＆偏極を示唆
d⌃ · p nF (1 nF ) !⇢ + 2 t̂µ µ⇢ ⌧⌃
SILE=⌧
R✏ (p) ph · p nF
- shear termを入れることで“spin puzzle”は、一応解決しそう
8mTdec ⌃ d⌃Rd⌃ · p nF (1 nF ) !⇢ + 2 t̂⌃µ⇢ ⌧R local equilib✏
where ILE pstands
for isothermal⌧
8mTdec ⌃ d⌃ · p nF
1
7(@ u⇢ local@⇢ u equilib)
where ILE stands!⇢for=isothermal
2
0.004
1 and:µisthekinematic
vorticity
T
/(e
+
P
)
=
0.08
th
!⇢ = (@ u⇢ @⇢ u )vorticity:µw = 0.8 fm
2
0.003
th + SIP(BBP)3µesw = 0.5 GeV/fm
1th + SIP(LY)⌅(@u⇢ + @ ⇢ u )shear:µisthekinematic
vorticity
and:
⇢ =
0.002
+
SIP(LY)
+
µ
IP
B
th
2
STAR
1
0.001
is the kinematic shear,
includingthe⌅⇢ = (@ u⇢ +@⇢properlyu )2
tensor as well as the expansion
scalar @ · u a
0.000
B. Futerms.
et al., PRL127,
142301the(2021)
ation
Therefore,
equation
(10)
is
the
kinematic
shear,
includingtheproperly
F. Becattini et al., PRL127, 272302 (2021)
| |<1
0.001
approximationof thethe expansion
spin polarization
tensoras wellet as
scalar @ vecto·u a0.5 < pT < 3 GeV
S. Alzharanial.,arXiv:2203.15718
1/2 baryon,
local thermodynamic
equilibr
20-60% Au+Au @ 200 GeV
0.002
ation
terms. atTherefore,
the equation
(10)
0.0
0.5
1.0
1.5
2.0
2.5
3.0 linear order in the gradients of the thermody
approximation of the spin polarization vecto
2!19
for a fixed decoupling temperature hypersu<latexit sha1_base64="vMCmCBvrQqvMkcZe5c78yK19qu0=">AAAB63icbVBNSwMxEJ3Ur1q/qh69BIvgqeyKoMeiF48VbC20S8mm2W5okl2SrFCW/gUvHhTx6h/y5r8x2+5BWx8MPN6bYWZemApurOd9o8ra+sbmVnW7trO7t39QPzzqmiTTlHVoIhLdC4lhgivWsdwK1ks1IzIU7DGc3Bb+4xPThifqwU5TFkgyVjzilNhCGqQxH9YbXtObA68SvyQNKNEe1r8Go4RmkilLBTGm73upDXKiLaeCzWqDzLCU0AkZs76jikhmgnx+6wyfOWWEo0S7UhbP1d8TOZHGTGXoOiWxsVn2CvE/r5/Z6DrIuUozyxRdLIoygW2Ci8fxiGtGrZg6Qqjm7lZMY6IJtS6emgvBX355lXQvmr7X9O8vG62bMo4qnMApnIMPV9CCO2hDByjE8Ayv8IYkekHv6GPRWkHlzDH8Afr8AROIjj8=</latexit>

Ψ2

0.001

sgn(α H) 〈cos(θp*)〉z

Ru+Ru&Zr+Zr sNN = 200 GeV
STAR preliminaryCentrality: 20%-60%

0.00050−0.0005
fit: p +2p sin(2φ-2Ψ )
0

Λ

1

2

p =0.020±0.002 [%]1−0.001Λ0

p =0.021±0.002 [%]124sgn(α H) 〈cos(θp*)〉

sub

2(φ-Ψ

z

<latexit sha1_base64="KZUT9J8793cQJ2moke8sZHPQIEw=">AAAB8XicbVBNS8NAEJ3Ur1q/qh69LBbBU0lE0GPRi8cK9gObUDbbSbt0swm7G6GE/gsvHhTx6r/x5r9x2+agrQ8GHu/NMDMvTAXXxnW/ndLa+sbmVnm7srO7t39QPTxq6yRTDFssEYnqhlSj4BJbhhuB3VQhjUOBnXB8O/M7T6g0T+SDmaQYxHQoecQZNVZ6zP0wIn464tN+tebW3TnIKvEKUoMCzX71yx8kLItRGiao1j3PTU2QU2U4Ezit+JnGlLIxHWLPUklj1EE+v3hKzqwyIFGibElD5urviZzGWk/i0HbG1Iz0sjcT//N6mYmug5zLNDMo2WJRlAliEjJ7nwy4QmbExBLKFLe3EjaiijJjQ6rYELzll1dJ+6LuuXXv/rLWuCniKMMJnMI5eHAFDbiDJrSAgYRneIU3RzsvzrvzsWgtOcXMMfyB8/kDYtCQtw==</latexit>

0.001

6
TPC
2

) [rad]Ru+Ru&Zr+Zr sNN = 200 GeV
STAR preliminaryCentrality: 20%-60%

0.0005Figure 5ashows how the ⇤’s polarization depends on
the specific shear viscosity used in the hydrodynamic
phase. Similar to the anisotropic flow coefficients, a large
specific shear viscosity
leads to a significant suppression
0
global polarization. This result is expected becauseΨthe3
shear viscosity smears out the flow velocity gradients andthe simulations will end up with smaller vorticity on the−0.0005
particlization
surface. Comparing the relative magnifit: p +2p sin(3φ-3Ψ )tudes of suppression in polarizationandanisotropic
flow
0
1
3
Λ comparable.
in Fig. 1, we find they are
Figurep =0.006±0.002[%] 5b shows1
a substantial
sensitivity Λof thep ⇤’s
globalpolarizationon−0.001=0.010±0.002[%]
1
the initial hot spot size. A smaller hot spot size leads
02
46
to larger spatial gradientsat theearly time,
which build
up the stronger hydrodynamic flow. Therefore,small
3(φ-ΨTPC) a[rad]3w results in larger thermal vorticity at the particlizationhcos( p )i

sub

Local polarization in isobar collisions

〈P z sin[n(φ-Ψn)]〉 [%]Local polarization in isobar collisionsrd
The 3 order Fourier coefficient of 𝑃

1

9Isobar sNN = 200 GeV

S. Alzharani, S. Ryu, and C. Shen, arXiv:2203.15718

STAR preliminary

0.20

Ru+Ru&Zr+Zr, Λ +Λ
n=2

0.5

𝑧

Posters by T. Niida (STAR), S. Ryu
Event-by-event AMPT + MUSIC
Talk by B. Fu

n=1
n=2
n=3

0.15

n=3

n=4
n=5

QM22, Baochi Fu

Au+Au@200 GeV

00.5<p <6 GeV/ c , |y |<1 αΛ=-αΛ=0.732±0.014
T

0

20

40

60

80

pzn{SP} (%)

0.10
0.05
0.00

𝒇𝟑 : induced by IC fluc.

1

Isobar sNN = 200 GeV
STAR preliminary
Ru+Ru&Zr+Zr, Λ +Λ

0.10

𝒇𝟑 : induced by IC fluc.

T /(e + P ) = 0.08, w = 0.8 fm
esw = 0.5 GeV/fm3µ
th + SIP(BBP)

0.05

2

〈P z sin[2(φ-Ψ )]〉 [%]Centrality [%]

0

20

40
Centrality(%)

60

80

Au+Au 200 GeV, Λ +Λ

0.5

Pb+Pb 5.02 TeV, Λ +Λe) The hcos(✓p⇤(ALICE))i in Eq. (24) with respect
vent plane angle computed from the ⇤’stion P z ( ) using four combinations of
n 20-60% Au+Au collisions.
00.5<p <6 GeV/ c , |y |<1 αΛ=-αΛ=0.732±0.014

ro pz2 {SP},
0

T

while
two finite
val-80
20 the 40
60
ity give comparable pz2 {SP}Centrality
in cen-[%]pheral collisions. Figure 8b showsoefficient has a mild dependence on

FIG. 10. (Color Online) The centrality dependence of then-th order Fourier coefficients of P z ( ) with respect to n-th
Shearを取り入れた流体計算は、２次＆3次とも定性的に再現（符号と強度）
order event-plane
determined by charged hadron anisotropic
flow in Au+Au •collisions
at 200GeV
for n = 1 to
5. 𝑓 in both Au+Au and Ru+Ru systems
Non-zero𝑓 iscomparable

2
constraint on η/s- 理想流体ではP3 zがゼロになるという点で、addional• Spin polarization also probes the initial state fluctuations

test whether this theoretical model is valid or not.
In Fig. 10, we compute the scalar-product pzn {SP}between the Fourier coefficients of P z ( ) and charged
hadron anisotropic flow vn for n = 1 5 as functions

BF & H. Song, in!20

discover effects indicative of new physics.
588
R. Rapp, H. van Hees / Physicswe
Letters Butilize
753 (2016) 586–590
For the temperature determination
themedium effects on the EM spectral function are p
Table 1
2 its initial
2 longitudinal size
TalkbyYe (STAR)
Excitation
functionoffireballparametersfor(z ) andsmall, of order T / M , providinga Z.
stablethermotemperature (T ), equation of state (T ), and chemical/kinetic freeze-out (T , µ ,2T ) Imconditions.
&EM ∝ M , and in nonrelativistic approximation, o√√nline.) Excess dimuon invariant-mass spectra in In–In( sNN =Medium temperature with dileptons

ions at the SPS. Theoretical calculations (solid line), composed ofon (using in-medium ρ and ω spectral functions and multi-pion anchiral mixing, dashed line) and QGP radiation (using a lattice-QCD
tted line) are compared to NA60 data [49,12].

Fully Corrected Data
vs.
Cocktail"invariant" mass分布のfitから、 radial flowによるblue-shit freeな温度測定
Medium
0

0

ch
B

ch

kin

s (GeV)

√

pc

6.3

8.8

19.6

62.4

200

z0 (fm/c)
2.1
1.87
1.41
0.94
0.63
T 0 (MeV)
185
198
238
291
363
= 54.4 GeV170(0-80%)170
T pcSTAR(MeV) Au+Au
161 s
170
NN 163T ch (MeV)
134
148
160
160
160
0
0
Rapp
and
Hess, PLB753(2016)586
p0 ® g ee & 460
p ®eeh ® g eew ®62
ee & w ®
p ee22
µch
(MeV)
390
197
B
T kin (MeV)
113
104
h' ® g ee 114
f ® ee & f ®111
hee
J/ y108
® ee

3/2

0

-1

-3

-3

-5

-5

NN

April 07, 2022

Zaochen Ye at QM2022 - Krakow, Poland

10(d2NExcess/dM/dy)/(dN /dη) (20 MeV/c2)-1-10dN/dM (c2/GeV)

02

dN/dM (c /GeV)

exp(−M / T ) ,(62.4) GeV. STARAt topSPSsNNenergy( (0-80%)sNN ≃ 20 GeV) we 10 dR ll /dM ∝ ( M T )Au+Au= 27 GeV
Precisfm/c which isp ®slightly
than theg ee & p ®ee smallerh ® g eew ®ee &“standard”
w ® p eeblue-swhichisindependentofthemedium’scollective
flow,h' ® g ee
f ® ee & f ® hee
J/ y ® ee
m/c employed in Ref. [19], mainly to better describe
cc ® ee
DY ® ee
Cocktail Sumcc® ee
DY ® ee
Cocktail Sum
noblue-shifteffects.
The
observed
spectranecessari
10
MR spectra while staying above the nuclear overlap10
Eff. and Acc. Corrected
Data
Eff. andAcc.fireballCorrected evolution,Data
average
over
the
but
the
choiceoγ = 0.7 fm/c (which may be considered a lower limit
dow, 1.5 GeV ≤STAR
M≤2.5 GeV, implies T ≪ M and theSTAR
Preliminary
Preliminary
ation). We then extrapolated
thesevalues to lower
√
(IMR)
−
0.35
enhancesthesensitivity
to
the
early
high-Tphases10h a power-law fit z0 = 4( sNN ), resulting in the10Fig. 2. (Color online.) Ex√
tion. Since primordial (and pre-equilibrium)
contribu
intermediate-mass
dilep
s for sNN = 8.77 GeV and 6.27 GeV. At these enerdashed line) and initial t
expected to be of exponential shape (e.g.,powerlatral heavy-ion
collisions
n between τ0 and z0 is no longer meaningful. Rather,(LMR)
variation in the initial lo
Yan), their “contamination” may be judged
the1. Tues quoted
10 initial energy densities obtained from our z 010
pare the+ - byin Table
temperature
regime at v
eeThe
slopes,Tquantities
00.5
1 e.g.,
1.5Fig. 6.2
2
3 of “The3.5
s , extrac
variouscompu
0 the0.5exponential
1
1.5 ansatz.
2
2.5 inverse
3
3.5
nsport calculations,cf.,
in2.5part III
2
2
LMR
IMR
IMR
LMR
Mee(GeV/c )M(GeV/c) are displayed
thermalradiationas
computedabove
eebook” [26] (page 638). For example, for E lab = 20 GeV
suitably chosen inva√√
collision energies of sNN = 6–200 GeV. We
find
a sm
viewedas a predictsNN = 6.27 GeV) various dynamical models
ng to
Clear
enhancementcompared
to cocktail
contributions
inbothdiscover effects indi
LMR
(low
mass
region):Mee<Mφ√rangingfromT ≃ 160
MeV.
The latmaximal excitation energy density (in the center of Fig. 1.dence(Color online.)
Excess dimuon
invariant-mass
spectraMeVin In–In(tos 260=
For the tempera1
IMR (intermediate
mass
region):Mφ<M
17.3 GeV) collisions at the SPS. Theoretical calculations (solid line), composed ofee<MintermediateJ/Ψ
3 region∗IMR
isdominatedby
QGP
thermalradiation
low
mass
(LMR)
and
mass
region(IMR)
ambiguously
indicatesthatathermalized
QGP effects
withon2of ϵmax = 1.6–2.4 GeV/fm , compared to an average hadronic radiation (using in-medium ρ and ω spectral functions and multi-pion an- medium
small, of order T
nihilation with chiral mixing, dashed line) and QGP radiation (using a lattice-QCD
3
2
well
above
the
pseudo-critical
one
has
been
producedIm&∝M, and i
inspiredrate,
dottedline)
arecompared
to
NA60
data
[49,12].
EM/fm in our fireball for z0 = 2.1 fm. This appears to!21
10

discover effects indicative of new physics.
For the temperature determination we utilize themedium effects on the EM spectral function are p
2
2
Talk byYe (STAR)
small, of order T / M , providinga Z.
stablethermo2
Im &EM ∝ M , and in nonrelativistic approximation, o√nline.) Excess dimuon invariant-mass spectra in In–In( sNN =Medium temperature with dileptons

ions at the SPS. Theoretical calculations (solid line), composed ofon (using in-medium ρ and ω spectral functions and multi-pion anchiral mixing, dashed line) and QGP radiation (using a lattice-QCD
tted line) are compared to NA60 data [49,12].
/dM/dy)/(dN /dh) (20 MeV/c2)-1

Low + Intermediate Mass Thermal Dielectron

Medium"invariant"radial flowによるblue-shit freeな温度測定
IMR:mass分布のfitから、
QGP thermometer

STAR Au+Au 54.4 GeV (0-80%)√
3/2
STAR Au+Au 27 GeV (0-80%)
dR ll /dM ∝ ( M T ) exp(−M / T ) ,(62.4) GeV. At top
SPS
energy
(
s
≃
20
GeV)
we
NN
PrecisNA60 In+In 17.3 GeV (dN /dh > 30)
27
GeV
and
54.4
GeV
data
are
-6
ch
B
10
fm/c which is slightly smaller than the “standard”
Rapp and Hess, PLB753(2016)586
blue-sTemperature vs. μ

consistent,
andis higher
than NA60
which
independentof the medium’s collective flow,

STAR: PLB 750 (2015) 64-71, arXiv: 1810.10159

HotQCD: PLB 795 (2019) 15-21

PC

ch

ch

ch

Tch SH: P. Braun-Munzinger et al. Nature 561, 321-330 (2018)
Tch GCE/SCE: STAR PRC 96, 044904 (2017)

HADES: Nature Physics 15, 1040-1045 (2019)
NA60: EPJC (2009) 59 607–623
G. Tetyana: JPS Conf.Proc. 32 (2020) 010079
April 07, 2022
Zaochen Ye at QM2022 - Krakow, Poland(d2NExcess/dM/dy)/(dN /dη) (20 MeV/c2)-1

T (MeV)

-M/T

(d N

2 Excesschfit by M to´ ebetter describe
m/c employed in Ref. [19], mainly
400
Thermaldileptons
Au+Au 54.4 GeV
noblue-shifteffects.
The
observed
spectranecessari
TIMR= 338 ± 59 MeV
STAR
Preliminary
MR spectra while staying above the nuclear overlap 350• T always higher th
Au+Au 27 GeV
averageoverthefireballevolution,but
thechoiceo
TIMR= 301 ± 60 MeV
IMR
LMR
STAR
γ = 0.7 fm/c (which may be considered a lower limit 300 IMR LMR NA60 (In+In)
at RHIC and NA60
10-8dow, 1.5LMR
GeV≤ M ≤ 2.5 GeV, implies • TEmitted≪ M from
and QGPtheation). We then extrapolated these values to lower
HADES
250
√
(IMR)
−
0.35
enhancesLMR STARthe
BES-I sensitivity to the early high-T phases
h a power-law fit z0 = 4( sNN ), resulting in the√
200tion. Since primordial (and pre-equilibrium)
Thermalcontribu
dileptonss for sNN STAR= 8.77Preliminary
GeV and 6.27 GeV. At these enerT closepower
to both Tlac150expected to be of exponential shape• (e.g.,n between
τ
and
z
is
no
longermeaningful.
Rather,(LMR)
0
0•
Emitted
from
had
-10
10
LQCD “contamination” may be judged by thepare the initial energy densities obtained from our z0 100Yan), T their+phase,
dominantl
0.5
1
1.5
2
2.5
T SH
T GCE
T SCE
e
e
2
the
exponential
ansatz.
The
inverseslopes,50
s , extrac
Mll III(GeV/c)phaseTtransition
nsport calculations,of “TheNA60: EPJC (2009) 59: cf.,
607–623e.g., Fig. 6.2 in partare displayed
0thermal radiation as computed abovebook” [26] (page 638). For example, for E lab = 20 GeV√102√ April 07, 2022
Zaochen Ye at QM2022 - Krakow, Poland
14
1
10
103
collision energies of sNN = 6–200µ (MeV)GeV. We find a sm
sNN dilepton= 6.27 mass
GeV) spectra
variousfrom
dynamical
modelsng toExcess
STAR BES,
B
dence ranging from T ≃ 160 MeV to 260 MeV. The lat1
comparingto NA60
dimuonresult (in the center ofmaximalexcitationenergydensity
SPSよりもRHICの方がmediumの温度が高い
3∗
ambiguously indicates that a thermalized QGP withof ϵmax = 1.6–2.4 GeV/fm , compared to an average(27-54GeVにしては)高すぎるかもしれない(ただし誤差も大きい)
3
well
above
the
pseudo-criticalone has been produced/fm in our fireball for z0 = 2.1 fm. This appears to!22
3/2

Summaryisongoing• Search for CP/crossover/1st-order phase transition
Successful Operation of STA• No conclusive result/signature so far (in my opinion)

Run 20 and 21 completed successfully
created smooth & dCooling medium(LEReC)issystem,• New results at lower energies (~3 GeV) where baryon-rich

BES-I

BES-II

FXT

0.4

0.5

3.0

3.2

3.5

3.9

4.5

5.2

6.2

7.2

9.2

7.7

5
11.

14.
13.5
7

3

6

17.

19.

0
27.

0
39.

10

4

62.
54.4
4

so more interesting results will come soon.

Data taken by STAR BES-I&II + Fixed-Target program

Events (M)• Data taking of BES-II just completed,sNN (GeV)

103
102
10
0.1

0.2

0.3

µ (GeV)
B

0.6

0.7

!23

Backup!24

Discussions – Separate Fitting of $, %Au + Au Collisions at Mid-rapidity
CentralGray: p, K, p (BES-I)

150

Indicate a different
equation of state (EoS)

Temperature T

kin

(MeV)

Peripheral

Ø At 3 GeV Au+Au collisions, the freeze-out
parameters (T/01 , β2 ) show different trend
compared to that of higher energy
collisions

7.7 GeV

200 GeV100

Ø The freeze-out parameter (T/01 ) of , issystematically higher than that of ( at 3
GeV, which is different from higher energies

STAR Preliminarypd 3 GeV

50

Open: p ; Solid: dp, d fit: 0.6 < p /A < 1.6 GeV/c

7.7, 19.6, 200 GeV

T

0.2

0.4

Collective Velocity áb ñ (c)T2022/4/7

0.6
L. Adamczyk et al. [STAR Collaboration] Phys.Rev.C 96 (2017) 4, 044904
B.I. Abelev et al. [STAR Collaboration] Phys.Rev.C 79 (2009) 034909

Hui Liu, QM2022 @ Krakow, Poland

21!25