Measurement of directed flow in <math><mrow><mi>Au</mi><mo>+</mo><mi>Au</mi></mrow></math> collisions at <math><mrow><msqrt><msub><mi>s</mi><mrow><mi>N</mi><mi>N</mi></mrow></msub></msqrt><mo>=</mo><mn>19.6</mn></mrow></math> and 27 GeV with the STAR event plane detector - INSPIRE

DataBETA

Measurement of directed flow in $Au + Au$ collisions at $\sqrt{s_{N N}} = 19.6$ and 27 GeV with the STAR event plane detector

STAR

Collaboration

Jun 22, 2024

15 pages

Published in:

Phys.Rev.C 111 (2025) 1, 014906

Published: Jan 9, 2025

e-Print:

2406.18213 [nucl-ex]

DOI:

10.1103/PhysRevC.111.014906 (publication)

Experiments:

View in:

ADS Abstract Service

reference search2 citations

Citations per year

Abstract: (APS)

In heavy-ion collision experiments, the global collectivity of final-state particles can be quantified by anisotropic flow coefficients

(v_{n})

. The first-order flow coefficient, also referred to as the directed flow

(v_{1})

, describes the collective sideward motion of produced particles and nuclear fragments in heavy-ion collisions. It carries information on the very early stage of the collision, especially at large pseudorapidity

(η)

, where it is believed to be generated during the nuclear passage time. Directed flow therefore probes the onset of bulk collective dynamics during thermalization, providing valuable experimental guidance to models of the pre-equilibrium stage. In 2018, the Event Plane Detector (EPD) was installed in STAR and used for the Beam Energy Scan phase-II (BES-II) data taking. The combination of EPD

(2.1 < | η | < 5.1)

and high-statistics BES-II data enables us to extend the

v_{1}

measurement to the forward and backward

η

regions. In this paper, we present the measurement of

v_{1}

over a wide

η

range in

Au + Au

collisions at

\sqrt{s_{N N}} =

19.6 and 27 GeV using the STAR EPD. The results of the analysis at

\sqrt{s_{N N}} =

19.6 GeV exhibit excellent consistency with the previous PHOBOS measurement, while elevating the precision of the overall measurement. The increased precision of the measurement also revealed finer structures in heavy-ion collisions, including a potential observation of the first-order event-plane decorrelation. Multiple physics models were compared to the experimental results. Only a transport model and a three-fluid hybrid model can reproduce a sizable

v_{1}

at large

η

as was observed experimentally. The model comparison also indicates

v_{1}

at large

η

might be sensitive to the QGP phase transition.

References(72)

Figures(15)

[1]

Evidence for a new state of matter: An Assessment of the results from the CERN lead beam program

Ulrich W. Heinz
(
- CERN
)
,
Maurice Jacob
(
- CERN
)

e-Print:
- nucl-th/0002042

[2]

Experimental and theoretical challenges in the search for the quark gluon plasma: The STAR Collaboration's critical assessment of the evidence from RHIC collisions

STAR

Collaboration

•

John Adams
(
- Birmingham U.
)

et al.

- Nucl.Phys.A 757 (2005) 102-183
•
e-Print:
- nucl-ex/0501009
•
DOI:
- 10.1016/j.nuclphysa.2005.03.085

[3]

Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

PHENIX

Collaboration

•

K. Adcox
(
- Vanderbilt U.
)

et al.

- Nucl.Phys.A 757 (2005) 184-283
•
e-Print:
- nucl-ex/0410003
•
DOI:
- 10.1016/j.nuclphysa.2005.03.086

[4]

The PHOBOS perspective on discoveries at RHIC

PHOBOS

Collaboration

•

B.B. Back
(
- Argonne
)

et al.

- Nucl.Phys.A 757 (2005) 28-101
•
e-Print:
- nucl-ex/0410022
•
DOI:
- 10.1016/j.nuclphysa.2005.03.084

[5]

Quark gluon plasma and color glass condensate at RHIC? The Perspective from the BRAHMS experiment

BRAHMS

Collaboration

•

I. Arsene
(
- Bucharest U.
)

et al.

- Nucl.Phys.A 757 (2005) 1-27
•
e-Print:
- nucl-ex/0410020
•
DOI:
- 10.1016/j.nuclphysa.2005.02.130

[6]

Hydrodynamic Modeling of Heavy-Ion Collisions

- Int.J.Mod.Phys.A 28 (2013) 1340011
•
e-Print:
- 1301.5893
•
DOI:
- 10.1142/S0217751X13400113

[7]

Early collective expansion: Relativistic hydrodynamics and the transport properties of QCD matter

Ulrich W. Heinz
(
- Ohio State U.
)

- Landolt-Bornstein 23 (2010) 240
•
e-Print:
- 0901.4355
•
DOI:
- 10.1007/978-3-642-01539-7_9

[8]

Collective flow and viscosity in relativistic heavy-ion collisions

Ulrich Heinz
(
- Ohio State U.
)
,
Raimond Snellings
(
- Utrecht U.
)

- Ann.Rev.Nucl.Part.Sci. 63 (2013) 123-151
•
e-Print:
- 1301.2826
•
DOI:
- 10.1146/annurev-nucl-102212-170540

[9]

Collective phenomena in non-central nuclear collisions

Sergei A. Voloshin
(
- Wayne State U.
)
,
Arthur M. Poskanzer
(
- LBL, Berkeley
)
,
Raimond Snellings
(
- NIKHEF, Amsterdam
)

- Landolt-Bornstein 23 (2010) 293-333
•
e-Print:
- 0809.2949
•
DOI:
- 10.1007/978-3-642-01539-7_10

[10]

Triangular flow in hydrodynamics and transport theory

- Phys.Rev.C 82 (2010) 034913
•
e-Print:
- 1007.5469
•
DOI:
- 10.1103/PhysRevC.82.034913

[11]

Collision geometry fluctuations and triangular flow in heavy-ion collisions

B. Alver
(
- MIT
)
,
G. Roland
(
- MIT
)

- Phys.Rev.C 81 (2010) 054905,
- Phys.Rev.C 82 (2010) 039903 (erratum)
•
e-Print:
- 1003.0194
•
DOI:
- 10.1103/PhysRevC.82.039903

[11]

Collision geometry fluctuations and triangular flow in heavy-ion collisions

B. Alver
(
- MIT
)
,
G. Roland
(
- MIT
)

- Phys.Rev.C 81 (2010) 054905,
- Phys.Rev.C 82 (2010) 039903 (erratum)
•
e-Print:
- 1003.0194
•
DOI:
- 10.1103/PhysRevC.82.039903

[12]

The first moment of azimuthal anisotropy in nuclear collisions from AGS to LHC energies

Subhash Singha
(
- Kent State U.
)
,
Prashanth Shanmuganathan
(
- Kent State U.
)
,
Declan Keane
(
- Kent State U.
)

- Adv.High Energy Phys. 2016 (2016) 2836989
•
e-Print:
- 1610.00646
•
DOI:
- 10.1155/2016/2836989

[13]

Methods for analyzing anisotropic flow in relativistic nuclear collisions

Arthur M. Poskanzer
(
- LBL, Berkeley
)
,
S.A. Voloshin
(
- Heidelberg U.
)

- Phys.Rev.C 58 (1998) 1671-1678
•
e-Print:
- nucl-ex/9805001
•
DOI:
- 10.1103/PhysRevC.58.1671

[14]

Dense nuclear matter equation of state from heavy-ion collisions

Agnieszka Sorensen
(
- Washington U., Seattle
)
,
Kshitij Agarwal
(
- Tubingen U.
)
,
Kyle W. Brown
(
- Michigan State U.
)
,
Zbigniew Chajęcki
(
- Western Michigan U.
)
,
Paweł Danielewicz
(
- Michigan State U.
)

et al.

- Prog.Part.Nucl.Phys. 134 (2024) 104080
•
e-Print:
- 2301.13253
•
DOI:
- 10.1016/j.ppnp.2023.104080

[15]

QCD Crossover at Finite Chemical Potential from Lattice Simulations

Szabolcs Borsanyi
(
- Wuppertal U.
)
,
Zoltan Fodor
(
- Wuppertal U. and
- Eotvos U. and
- IAS, Julich and
- UC, San Diego
)
,
Jana N. Guenther
(
- Wuppertal U. and
- Regensburg U.
)
,
Ruben Kara
(
- Wuppertal U.
)
,
Sandor D. Katz
(
- Eotvos U.
)

et al.

- Phys.Rev.Lett. 125 (2020) 5, 052001
•
e-Print:
- 2002.02821
•
DOI:
- 10.1103/PhysRevLett.125.052001

[16]

Chiral crossover in QCD at zero and non-zero chemical potentials

HotQCD

Collaboration

•

A. Bazavov
(
- Michigan State U., East Lansing (main)
)

et al.

- Phys.Lett.B 795 (2019) 15-21
•
e-Print:
- 1812.08235
•
DOI:
- 10.1016/j.physletb.2019.05.013

[17]

Canonical partition function and finite density phase transition in lattice QCD

Shinji Ejiri
(
- Brookhaven
)

- Phys.Rev.D 78 (2008) 074507
•
e-Print:
- 0804.3227
•
DOI:
- 10.1103/PhysRevD.78.074507

[18]

Critical Points in the Linear Sigma Model with Quarks

E.Scott Bowman
(
- Minnesota U.
)
,
Joseph I. Kapusta
(
- Minnesota U.
)

- Phys.Rev.C 79 (2009) 015202
•
e-Print:
- 0810.0042
•
DOI:
- 10.1103/PhysRevC.79.015202

[19]

Overview of the QCD phase diagram: Recent progress from the lattice

Jana N. Guenther
(
- Marseille, CPT
)

- Eur.Phys.J.A 57 (2021) 4, 136
•
e-Print:
- 2010.15503
•
DOI:
- 10.1140/epja/s10050-021-00354-6

[20]

An Experimental Exploration of the QCD Phase Diagram: The Search for the Critical Point and the Onset of De-confinement

STAR

Collaboration

•

M.M. Aggarwal
(
- Panjab U.
)

et al.

e-Print:
- 1007.2613

[21]

The QCD phase diagram and Beam Energy Scan physics: A theory overview

Lipei Du
(
- McGill U. and
- LBNL, NSD
)
,
Agnieszka Sorensen
(
- Washington U., Seattle
)
,
Mikhail Stephanov
(
- Illinois U., Chicago and
- Chicago U.
)

- Int.J.Mod.Phys.E 33 (2024) 07, 2430008,
- Int.J.Mod.Phys.E 33 (2024) 07, 2430008
•
e-Print:
- 2402.10183
•
DOI:
- 10.1142/S021830132430008X

[22]

Heavy Ion Collisions: The Big Picture, and the Big Questions

Wit Busza
(
- MIT, LNS
)
,
Krishna Rajagopal
(
- MIT, LNS and
- MIT, Cambridge, CTP
)
,
Wilke van der Schee
(
- MIT, Cambridge, CTP and
- Utrecht U.
)

- Ann.Rev.Nucl.Part.Sci. 68 (2018) 339-376
•
e-Print:
- 1802.04801
•
DOI:
- 10.1146/annurev-nucl-101917-020852

[23]

Reaching for the horizon: The 2015 long range plan for nuclear science (unpublished)

A. Aprahamian

[24]

Comparison of chemical freeze-out criteria in heavy-ion collisions

J. Cleymans
(
- UCT-CERN Res. Ctr. and
- Cape Town U.
)
,
H. Oeschler
(
- Darmstadt, Tech. Hochsch. and
- UCT-CERN Res. Ctr.
)
,
K. Redlich
(
- Wroclaw U. and
- CERN and
- Darmstadt, Tech. Hochsch.
)
,
S. Wheaton
(
- Wroclaw U. and
- UCT-CERN Res. Ctr. and
- Darmstadt, Tech. Hochsch.
)

- Phys.Rev.C 73 (2006) 034905
•
e-Print:
- hep-ph/0511094
•
DOI:
- 10.1103/PhysRevC.73.034905

1-25 of 72
1
2
3
25 / page