scholarly journals Polarization and Vorticity in the Quark–Gluon Plasma

2020 ◽  
Vol 70 (1) ◽  
pp. 395-423 ◽  
Author(s):  
Francesco Becattini ◽  
Michael A. Lisa
Keyword(s):  
Angular Momentum ◽  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Current Status ◽  
Future Research ◽  
Heavy Nuclei ◽  
Heavy Ion Physics ◽  
Flow Vorticity ◽  
Developing Area

The quark–gluon plasma (QGP) produced by collisions between ultrarelativistic heavy nuclei is well described in the language of hydrodynamics. Noncentral collisions are characterized by very large angular momentum, which in a fluid system manifests as flow vorticity. This rotational structure can lead to a spin polarization of the hadrons that eventually emerge from the plasma, and thus these collisions provide experimental access to flow substructure at unprecedented detail. Recently, the first observations of Λ hyperon polarization along the direction of collisional angular momentum were reported. These measurements are in broad agreement with hydrodynamic and transport-based calculations and reveal that the QGP is the most vortical fluid ever observed. However, there remain important tensions between theory and observation that might be fundamental in nature. In the relatively mature field of heavy-ion physics, the discovery of global hyperon polarization and 3D simulations of the collision have opened an entirely new direction of research. We discuss the current status of this rapidly developing area and directions for future research.

EVIDENCE FOR A QUARK-GLUON PLASMA AT RHIC

2007 ◽  
Vol 16 (03) ◽  
pp. 643-659 ◽  
Author(s):  
JOHN W. HARRIS
Keyword(s):  
Chemical Potential ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Nuclei ◽  
Relativistic Heavy Ion Collider ◽  
Heavy Ion Physics ◽  
Strongly Coupled ◽  
Hadron Phase ◽  
B Hadrons ◽  
Quark Level

This presentation is given in honor of Walter Greiner's 70th birthday, in recognition of the pioneering work of his "Frankfurt School" and their contributions to the field of heavy ion physics. Ultra-relativistic collisions of heavy nuclei at the Relativistic Heavy Ion Collider (RHIC) form an extremely hot system at energy densities greater than 5 GeV/fm3, where normal hadrons cannot exist. Upon rapid cooling of the system to a temperature T ~ 175 MeV and vanishingly small baryo-chemical potential, hadrons coalesce from quarks at the quark-hadron phase boundary predicted by lattice QCD. A large amount of collective (elliptic) flow at the quark level provides evidence for strong pressure gradients in the initial partonic stage of the collision when the system is dense and highly interacting prior to coalescence into hadrons. The suppression of both light (u,d,s) and heavy (c,b) hadrons at large transverse momenta, that form from fragmentation of hard-scattered partons, and the quenching of di-jets provide evidence for extremely large energy loss of partons as they attempt to propagate through the dense, strongly-coupled, colored medium created at RHIC.

scholarly journals Working group report: Heavy-ion physics and quark-gluon plasma

Pramana ◽  
2006 ◽  
Vol 67 (5) ◽  
pp. 961-981 ◽  
Author(s):  
Munshi G Mustafa ◽  
Sudhir Raniwala ◽  
T Awes ◽  
B Rai ◽  
RS Bhalerao ◽  
...  
Keyword(s):  
Quark Gluon Plasma ◽  
Working Group ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Ion Physics ◽  
Group Report

CURRENT STATUS OF PROPERTIES AND SIGNALS OF THE QUARK-GLUON PLASMA

1992 ◽  
Vol 07 (29) ◽  
pp. 7185-7237 ◽  
Author(s):  
C.P. SINGH
Keyword(s):  
Phase Transition ◽  
Quark Gluon Plasma ◽  
Quark Matter ◽  
National Laboratory ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Brookhaven National Laboratory ◽  
Current Status ◽  
State Of Matter ◽  
New State Of Matter

Heavy ion experiments at the AGS machine of Brookhaven National Laboratory and SPS of CERN are aimed at producing and diagnosing a new state of matter, the quark-gluon plasma. Some important and relevant issues involving the nature and the detection aspects of the phase transition from hadron to quark matter are reviewed in an introductory and pedagogical way.

scholarly journals Quark-gluon plasma: Status of heavy ion physics

Pramana ◽  
2000 ◽  
Vol 55 (1-2) ◽  
pp. 125-135 ◽  
Author(s):  
R V Gavai
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Ion Physics

scholarly journals Perturbative Accelerating Solutions of Relativistic Hydrodynamics

2017 ◽  
Author(s):  
Bálint Kurgyis ◽  
Máté Csanád
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Analytic Solutions ◽  
Relativistic Hydrodynamics ◽  
Heavy Ion Physics ◽  
Hubble Expansion ◽  
Initial States

In ultra-relativistic collisions of heavy ions, the strongly interacting Quark Gluon Plasma (sQGP) is created. The fluid nature of the sQGP was one of the important discoveries of high energy heavy ion physics in the last decades. Henceforth the explosion of this matter may be described by hydrodynamical models. Besides numerical simulations, it is important to study the analytic solutions of the equations of hydrodynamics, as these enable us to understand the connection of the final and initial states better. In this paper we present a perturbative, accelerating solution of relativistic hydrodynamics, on top of a known class of solutions describing Hubble-expansion. We describe the properties of this class of perturbative solutions, and investigate a few selected solutions in detail.

scholarly journals The First Moment of Azimuthal Anisotropy in Nuclear Collisions from AGS to LHC Energies

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Subhash Singha ◽  
Prashanth Shanmuganathan ◽  
Declan Keane
Keyword(s):  
Quark Gluon Plasma ◽  
Charged Particles ◽  
Theoretical Work ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Azimuthal Anisotropy ◽  
Flow Focusing ◽  
Nuclear Collisions ◽  
Ion Collisions ◽  
First Moment

We review topics related to the first moment of azimuthal anisotropy (v1), commonly known as directed flow, focusing on both charged particles and identified particles from heavy-ion collisions. Beam energies from the highest available, at the CERN LHC, down to projectile kinetic energies per nucleon of a few GeV per nucleon, as studied in experiments at the Brookhaven AGS, fall within our scope. We focus on experimental measurements and on theoretical work where direct comparisons with experiment have been emphasized. The physics addressed or potentially addressed by this review topic includes the study of Quark Gluon Plasma and, more generally, investigation of the Quantum Chromodynamics phase diagram and the equation of state describing the accessible phases.

scholarly journals Particle Production in Ultrarelativistic Heavy-Ion Collisions: A Statistical-Thermal Model Review

2013 ◽  
Vol 2013 ◽  
pp. 1-27 ◽  
Author(s):  
S. K. Tiwari ◽  
C. P. Singh
Keyword(s):  
Thermal Model ◽  
Heavy Ion Collisions ◽  
Particle Production ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Transverse Mass ◽  
Current Status ◽  
Thermal Models ◽  
Ion Collisions ◽  
Ultrarelativistic Heavy Ion Collisions

The current status of various thermal and statistical descriptions of particle production in the ultrarelativistic heavy-ion collisions experiments is presented in detail. We discuss the formulation of various types of thermal models of a hot and dense hadron gas (HG) and the methods incorporated in the implementing of the interactions between hadrons. It includes our new excluded-volume model which is thermodynamically consistent. The results of the above models together with the experimental results for various ratios of the produced hadrons are compared. We derive some new universal conditions emerging at the chemical freeze-out of HG fireball showing independence with respect to the energy as well as the structure of the nuclei used in the collision. Further, we calculate various transport properties of HG such as the ratio of shear viscosity-to-entropy using our thermal model and compare with the results of other models. We also show the rapidity as well as transverse mass spectra of various hadrons in the thermal HG model in order to outline the presence of flow in the fluid formed in the collision. The purpose of this review article is to organize and summarize the experimental data obtained in various experiments with heavy-ion collisions and then to examine and analyze them using thermal models so that a firm conclusion regarding the formation of quark-gluon plasma (QGP) can be obtained.

Study and Investigation of Hard Photons Emission in Heavy Ion Collisions

2021 ◽  
Vol 19 (2) ◽  
pp. 61-65
Author(s):  
Taghreed A. Younis ◽  
Hadi J.M. Al-Agealy
Keyword(s):  
Critical Temperature ◽  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Ion Collision ◽  
Hard Photon ◽  
Ion Collisions ◽  
Strength Models ◽  
Ion Collision

This work involves hard photon rate production from quark -gluon plasma QGP interaction in heavy ion collision. Using a quantum chromodynamic model to investigate and calculation of photons rate in 𝑐𝑔 → 𝑠𝑔𝛾 system due to strength coupling, photons rate, temperature of system, flavor number and critical. The photons rate production computed using the perturbative strength models for QGP interactions. The strength coupling was function of temperature of system, flavor number and critical temperature. Its influenced by force with temperature of system, its increased with decreased the temperature and vice versa. The strength coupling has used to examine the confinement and deconfinement of quarks in QGP properties and influence on the photon rate production. In our approach, we calculate the photons rate depending on the strength coupling, photons rate and temperature of system with other factors. The results plotted as a function of the photons energy. The photons rate was decreased with increased temperature and increased with decreased with strength coupling.

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