scholarly journals Charge-dependent flow as evidence of strong electromagnetic fields in heavy-ion collisions

2020 ◽  
Vol 35 (39) ◽  
pp. 2050324
Author(s):  
Andrea Dubla ◽  
Umut Gürsoy ◽  
Raimond Snellings
Keyword(s):  
Electromagnetic Fields ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Experimental Characterization ◽  
Ion Collisions ◽  
Current State ◽  
Theoretical Predictions ◽  
Dependent Flow

The extremely large electromagnetic fields generated in heavy-ion collisions provide access to novel observables that are expected to constrain various key transport properties of the quark-gluon plasma and could help solve one of the outstanding puzzles in QCD: the strong CP problem. In this review we present a brief overview of the theoretical and experimental characterization of these electromagnetic fields. After reviewing the current state, emphasizing one of the observables — the charge-dependent flow — we discuss the various discrepancies between the measurements and theoretical predictions. Finally, to help resolve the discrepancies, we suggest new measurements and theoretical ideas.

scholarly journals Charge-dependent flow induced by electromagnetic fields in heavy ion collisions

2021 ◽  
Vol 1005 ◽  
pp. 121837
Author(s):  
U. Gürsoy ◽  
D.E. Kharzeev ◽  
E. Marcus ◽  
K. Rajagopal ◽  
C. Shen
Keyword(s):  
Electromagnetic Fields ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Ion Collisions ◽  
Dependent Flow

scholarly journals Signatures of QGP at RHIC and the LHC

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
T. Niida ◽  
Y. Miake
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Jet Quenching ◽  
Theoretical Studies ◽  
Debye Screening ◽  
Direct Photons ◽  
Ion Collisions ◽  
Experimental And Theoretical Studies

AbstractThe progress over the 30 years since the first high-energy heavy-ion collisions at the BNL-AGS and CERN-SPS has been truly remarkable. Rigorous experimental and theoretical studies have revealed a new state of the matter in heavy-ion collisions, the quark-gluon plasma (QGP). Many signatures supporting the formation of the QGP have been reported. Among them are jet quenching, the non-viscous flow, direct photons, and Debye screening effects. In this article, selected signatures of the QGP observed at RHIC and the LHC are reviewed.

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.

scholarly journals Heavy Ion Collisions: The Big Picture and the Big Questions

2018 ◽  
Vol 68 (1) ◽  
pp. 339-376 ◽  
Author(s):  
Wit Busza ◽  
Krishna Rajagopal ◽  
Wilke van der Schee
Keyword(s):  
Lower Energy ◽  
Heavy Ion Collisions ◽  
Complex Dynamics ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Ion Collisions ◽  
Quantum Matter ◽  
Open Questions ◽  
Big Picture ◽  
Formation And Evolution

Heavy ion collisions quickly form a droplet of quark–gluon plasma (QGP) with a remarkably small viscosity. We give an accessible introduction to how to study this smallest and hottest droplet of liquid made on Earth and why it is so interesting. The physics of heavy ion collisions ranges from highly energetic quarks and gluons described by perturbative QCD to a bath of strongly interacting gluons at lower energy scales. These gluons quickly thermalize and form QGP, while the energetic partons traverse this plasma and end in a shower of particles called jets. Analyzing the final particles in various ways allows us to study the properties of QGP and the complex dynamics of multiscale processes in QCD that govern its formation and evolution, providing what is perhaps the simplest form of complex quantum matter that we know of. Much remains to be understood, and throughout the review big open questions are encountered.

scholarly journals On Pseudorapidity Distribution and Speed of Sound in High Energy Heavy Ion Collisions Based on a New Revised Landau Hydrodynamic Model

2015 ◽  
Vol 2015 ◽  
pp. 1-23 ◽  
Author(s):  
Li-Na Gao ◽  
Fu-Hu Liu
Keyword(s):  
Speed Of Sound ◽  
Hydrodynamic Model ◽  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
High Energy ◽  
Relativistic Heavy Ion Collider ◽  
Central Source ◽  
Ion Collisions

We propose a new revised Landau hydrodynamic model to study systematically the pseudorapidity distributions of charged particles produced in heavy ion collisions over an energy range from a few GeV to a few TeV per nucleon pair. The interacting system is divided into three sources, namely, the central, target, and projectile sources, respectively. The large central source is described by the Landau hydrodynamic model and further revised by the contributions of the small target/projectile sources. The modeling results are in agreement with the available experimental data at relativistic heavy ion collider, large hadron collider, and other energies for different centralities. The value of square speed of sound parameter in different collisions has been extracted by us from the widths of rapidity distributions. Our results show that, in heavy ion collisions at energies of the two colliders, the central source undergoes a phase transition from hadronic gas to quark-gluon plasma liquid phase; meanwhile, the target/projectile sources remain in the state of hadronic gas. The present work confirms that the quark-gluon plasma is of liquid type rather than being of a gas type.

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