scholarly journals Quark–gluon soup — The perfectly liquid phase of QCD

2015 ◽  
Vol 30 (02) ◽  
pp. 1530011 ◽  
Author(s):  
Ulrich Heinz
Keyword(s):  
Nuclear Physics ◽  
National Laboratory ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Brookhaven National Laboratory ◽  
Precise Determination ◽  
Relativistic Heavy Ion Collisions ◽  
Strongly Coupled ◽  
Ion Collisions

At temperatures above about 150 MeV and energy densities exceeding 500 MeV/fm3, quarks and gluons exist in the form of a plasma of free color charges that is about 1000 times hotter and a billion times denser than any other plasma ever created in the laboratory. This quark–gluon plasma (QGP) turns out to be strongly coupled, flowing like a liquid. About 35 years ago, the nuclear physics community started a program of relativistic heavy-ion collisions with the goal of producing and studying QGP under controlled laboratory conditions. This article recounts the story of its successful creation in collider experiments at Brookhaven National Laboratory and CERN and the subsequent discovery of its almost perfectly liquid nature, and reports on the recent quantitatively precise determination of its thermodynamic and transport properties.

STRONGLY INTERACTING QGP AND QUARKONIUM SUPPRESSION AT RHIC AND LHC ENERGIES

2012 ◽  
Vol 27 (02) ◽  
pp. 1250009 ◽  
Author(s):  
VINEET AGOTIYA ◽  
LATA DEVI ◽  
UTTAM KAKADE ◽  
BINOY KRISHNA PATRA
Keyword(s):  
Equation Of State ◽  
Degrees Of Freedom ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Strongly Coupled ◽  
Cornell Potential ◽  
Ion Collisions ◽  
Strongly Interacting ◽  
Strongly Coupled Plasma

We have developed an equation of state for strongly interacting quark–gluon plasma (QGP) in the framework of strongly coupled plasma with appropriate modifications to take account of color and flavor degrees of freedom and the interactions among themselves. For this purpose we used the effective potential to improve the plasma parameter (Γ) by correcting the full Cornell potential with a dielectric function embodying the effects of the deconfined medium and not its Coulomb part alone and obtain the equation of state in terms of Γ. Our results on thermodynamic observables viz. pressure, energy density, speed of sound etc. nicely fit to the results of lattice equation of state for gluon, massless as well massive flavored plasma. We have then employed our equation of state to estimate the quarkonium suppression in an expanding QGP produced in the relativistic heavy-ion collisions. We have found that our predictions matches with the recent PHENIX data on the centrality dependence of J/ψ suppression in Au+Au collisions at BNL RHIC within the limit of other uncertainties. We have also predicted for the ϒ suppression in Pb+Pb collisions at LHC energy which could be tested in the ALICE experiments at CERN LHC.

STUDIES OF SUPERDENSE HADRONIC MATTER IN A RELATIVISTIC TRANSPORT MODEL

2001 ◽  
Vol 10 (04n05) ◽  
pp. 267-352 ◽  
Author(s):  
BAO-AN LI ◽  
A. T. SUSTICH ◽  
BIN ZHANG ◽  
C. M. KO
Keyword(s):  
Heavy Ion Collisions ◽  
Transport Model ◽  
National Laboratory ◽  
Heavy Ion ◽  
Brookhaven National Laboratory ◽  
Hadronic Matter ◽  
Relativistic Heavy Ion Collisions ◽  
Kaon Production ◽  
Superdense Matter ◽  
Ion Collisions

Transport models have been very useful in studying the properties of the hot, dense matter that is created in relativistic heavy-ion collisions. We review here a Relativistic Transport (ART) Model and its applications in heavy ion collisions at beam energies below about 10 AGeV available from the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The model allows one to study not only the reaction dynamics leading to the formation of superdense hadronic matter, but also to explore the effects due to the nuclear equation of state and the deformation/orientation of the colliding nuclei on the size and lifetime of the superdense matter. We also discuss the dependence of the central baryon and energy densities, the degree of thermalization, and the collective radial flow velocity of the superdense matter on the beam energy. We further review how the properties of the superdense hadronic matter can be determined from studying the collective flow of nucleons, pions and kaons in these collisions. We finally discuss the mechanisms for kaon production in relativistic heavy-ion collisions and review the progress in extracting the kaon in-medium properties from these collisions.

scholarly journals Anisotropic Flow Measurements at RHIC

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 178
Author(s):  
A Taranenko
Keyword(s):  
Strong Evidence ◽  
Quark Gluon Plasma ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Rhic Energy ◽  
Relativistic Heavy Ion Collisions ◽  
Flow Measurements ◽  
Strongly Coupled ◽  
Anisotropic Flow ◽  
Ion Collisions

Anisotropic flow measurements in relativistic-heavy ion collisions at RHIC-BNL and LHC-CERN have provided strong evidence for the formation of a strongly coupled Quark-Gluon Plasma (sQGP). In this article, we briefly review and discuss the recent results of anisotropic flow measurements from the STAR and PHENIX experiments at RHIC, such as 1) new measurements at top RHIC energy √

scholarly journals Heavy Ion Physics and Quark-Gluon Plasma

2005 ◽  
Vol 20 (14) ◽  
pp. 2951-2962 ◽  
Author(s):  
J. L. Nagle
Keyword(s):  
Coming Out ◽  
National Laboratory ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Brookhaven National Laboratory ◽  
Experimental Results ◽  
Relativistic Heavy Ion Collider ◽  
Heavy Ion Physics ◽  
Strongly Coupled ◽  
American Physical

These proceedings represent a brief overview of the exciting physics coming out from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The experimental results from BRAHMS, PHOBOS, PHENIX and STAR indicate a strongly-coupled state of matter that can only be described on the partonic level. We review some of the latest experimental results as we presented at the meeting of the Division of Particles and Fields of the American Physical Society in Riverside, CA in August 2004.

scholarly journals STUDYING DIQUARK STRUCTURE OF HEAVY BARYONS IN RELATIVISTIC HEAVY ION COLLISIONS

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2254-2258
Author(s):  
S. YASUI ◽  
S. H. LEE ◽  
K. OHNISHI ◽  
I.-K. YOO ◽  
C. M. KO
Keyword(s):  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Coalescence Model ◽  
Strongly Coupled ◽  
Ion Collisions ◽  
Heavy Baryons ◽  
Three Body

We propose the enhancement of Λc yield in heavy ion collisions at RHIC and LHC as a novel signal for the existence of diquarks in the strongly coupled quark-gluon plasma produced in these collisions as well as in the Λc. Assuming that stable bound diquarks can exist in the quark-gluon plasma, we argue that the yield of Λc would be increased by two-body collisions between [ud] diquarks and c quarks, in addition to normal three-body collisions among u, d and c quarks. A quantitative study of this effect based on the coalescence model shows that including the contribution of diquarks to Λc production indeed leads to a substantial enhancement of the Λc/D ratio in heavy ion collisions.

scholarly journals HEAVY ION PHYSICS AT RHIC

2008 ◽  
Vol 17 (05) ◽  
pp. 771-801 ◽  
Author(s):  
M. J. TANNENBAUM
Keyword(s):  
National Laboratory ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Nucleon Nucleon ◽  
Big Bang ◽  
Brookhaven National Laboratory ◽  
Relativistic Heavy Ion Collider ◽  
Heavy Ion Physics ◽  
Ion Collisions ◽  
Dense Nuclear Matter

The status of the physics of heavy ion collisions is reviewed based on measurements over the past 6 years from the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The dense nuclear matter produced in Au + Au collisions with nucleon-nucleon c.m. energy [Formula: see text] at RHIC corresponds roughly to the density and temperature of the universe a few microseconds after the ‘big-bang’ and has been described as “a perfect liquid” of quarks and gluons, rather than the gas of free quarks and gluons, “the quark-gluon plasma” as originally envisaged. The measurements and arguments leading to this description will be presented.

JET CONVERSIONS IN QGP AND SUPPRESSION OF IDENTIFIED HADRONS

2007 ◽  
Vol 16 (07n08) ◽  
pp. 1930-1936 ◽  
Author(s):  
WEI LIU ◽  
CHE MING KO ◽  
BEN-WEI ZHANG
Keyword(s):  
Transverse Momentum ◽  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
High Transverse Momentum ◽  
Ion Collisions ◽  
Conversion Rates ◽  
Gluon Jets

A gluon or quark jet traversing through a quark-gluon plasma can be converted into a quark or gluon jet through scatterings with thermal partons. Their conversion rates due to two-body elastic and inelastic scattering as well as scatterings involving gluon radiation are evaluated in the lowest order in Quantum Chromodynamics (QCD). Including both energy loss and conversions of quark and gluon jets in the expanding quark-gluon plasma produced in relativistic heavy ion collisions, we find a net conversion of quark jets to gluon jets. This reduces the difference between the nuclear modification factors for quark and gluon jets in central heavy ion collisions and thus enhances the p/π+ and [Formula: see text] ratios at high transverse momentum. Using the larger QCD coupling constant from lattice QCD calculations than that given by the perturbative QCD further enhances the net quark to gluon jet conversion rate, leading to a closer similarity between these ratios at high transverse momentum in central Au + Au collisions at [Formula: see text] and in p + p collisions at same energy as observed in experiments.

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