AZIMUTHAL DEPENDENCE OF ENERGY FLOW IN CENTRAL COLLISIONS OF HEAVY NUCLEI

1994 ◽  
Vol 09 (13) ◽  
pp. 1151-1157 ◽  
Author(s):  
C. HARTNACK ◽  
J. AICHELIN ◽  
H. STÖCKER ◽  
W. GREINER
Keyword(s):  
Nuclear Matter ◽  
Heavy Ion ◽  
Momentum Dependence ◽  
Mass Dependence ◽  
Heavy Nuclei ◽  
Emission Pattern ◽  
Central Collisions ◽  
Ion Collisions ◽  
Dense Nuclear Matter ◽  
Squeeze Out

Microscopic VUU and QMD calculations, which include the momentum dependence of the nuclear interactions, both predict the observed collective off-plane squeeze-out of nuclear matter in heavy ion collisions. A strong projectile mass dependence is found, in agreement with the data. A fragment mass dependence of the emission pattern is predicted. The off-plane squeeze-out is sensitive to the bulk properties of hot and dense nuclear matter, namely the nuclear viscosity and the equation of state.

Study of Signals of Hot and Dense Nuclear Matter in Heavy-Ion Collisions at NICA Energies Using Micro- and Macroscopic Models

2021 ◽  
Vol 52 (4) ◽  
pp. 544-548
Author(s):  
E. E. Zabrodin ◽  
A. S. Botvina ◽  
L. V. Bravina ◽  
G. Kh. Eyyubova ◽  
Yu. B. Ivanov ◽  
...  
Keyword(s):  
Nuclear Matter ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Macroscopic Models ◽  
Ion Collisions ◽  
Dense Nuclear Matter

scholarly journals Upgrading the Baryonic Matter at the Nuclotron Experiment at NICA for Studies of Dense Nuclear Matter

Particles ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 481-490
Author(s):  
Peter Senger ◽  
Dmitrii Dementev ◽  
Johann Heuser ◽  
Mikhail Kapishin ◽  
Evgeny Lavrik ◽  
...  
Keyword(s):  
Neutron Star ◽  
Nuclear Matter ◽  
Nuclear Research ◽  
Feasibility Studies ◽  
Heavy Ion ◽  
High Density ◽  
Baryonic Matter ◽  
Ion Collisions ◽  
Dense Nuclear Matter ◽  
Density Equation

The Nuclotron at the Joint Institute for Nuclear Research in Dubna can deliver gold beams with kinetic energies between 2 and 4.5 A GeV. In heavy-ion collisions at these energies, it is expected that the nuclear fireball will be compressed by up to approximately four times the saturation density. This offers the opportunity to study the high-density equation-of-state (EOS) of nuclear matter in the laboratory, which is needed for our understanding of the structure of neutron stars and the dynamics of neutron star mergers. The Baryonic Matter at the Nuclotron (BM@N) experiment will be upgraded to perform multi-differential measurements of hadrons including (multi-) strange hyperons, which are promising probes of the high-density EOS, and of new phases of quantum chromodynamic (QCD) matter. The layout of the upgraded BM@N experiment and the results of feasibility studies are presented.

scholarly journals Transport Model Approach to Λ and Λ¯ Polarization in Heavy-Ion Collisions

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1852
Author(s):  
Larissa V. Bravina ◽  
Kyrill A. Bugaev ◽  
Oleksandr Vitiuk ◽  
Evgeny E. Zabrodin
Keyword(s):  
Nuclear Matter ◽  
Heavy Ion Collisions ◽  
Transport Model ◽  
Center Of Mass ◽  
Heavy Ion ◽  
Baryon Density ◽  
Dense Medium ◽  
Interaction Point ◽  
Ion Collisions ◽  
Dense Nuclear Matter

This paper investigates the symmetry breaking between the polarizations of Λ and Λ¯ hyperons in relativistic collisions of heavy ions at intermediate and low energies. The microscopic transport model UrQMD is employed to study the thermal vorticity of hot and dense nuclear matter formed in non-central Au + Au collisions at center-of-mass energies 7.7≤sNN≤62.4 GeV. The whole volume of an expanding fireball is subdivided into small cubic cells. Then, we trace the final Λ and Λ¯ hyperons back to their last interaction point within a certain cell. Extracting the bulk parameters, such as energy density, net baryon density, and net strangeness of the hot and dense medium in the cell, one can obtain the cell temperature and the chemical potentials at the time of the hyperon emission. To do this, the extracted characteristics have to be fitted to the statistical model (SM) of ideal hadron gas. After that, the vorticity of nuclear matter and polarization of both hyperons are calculated. We found that the polarization of both Λ and Λ¯ increases with decreasing energy of heavy-ion collisions. The stronger polarization of Λ¯ is explained by (i) the slightly different freeze-out conditions of both hyperons and (ii) the different space–time distributions of Λ and Λ¯.

Exploring Baryon Rich Matter with Heavy-Ion Collisions

2019 ◽  
Vol 64 (7) ◽  
pp. 583 ◽  
Author(s):  
S. Harabasz
Keyword(s):  
Center Of Mass ◽  
Heavy Ion ◽  
State Density ◽  
Heavy Nuclei ◽  
First Order ◽  
Center Of Mass Energy ◽  
Ion Collisions ◽  
Deconfinement Phase Transition ◽  
Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

scholarly journals Quarkonia Formation in a Holographic Gravity–Dilaton Background Describing QCD Thermodynamics

Particles ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 159-177
Author(s):  
Rico Zöllner ◽  
Burkhard Kämpfer
Keyword(s):  
Quark Mass ◽  
Heavy Ion ◽  
Mass Dependence ◽  
Holographic Model ◽  
Spectral Functions ◽  
Special Aspect ◽  
Quark Masses ◽  
Ion Collisions ◽  
Heavy Quark Mass ◽  
Quark Mass Dependence

A holographic model of probe quarkonia is presented, where the dynamical gravity–dilaton background was adjusted to the thermodynamics of 2 + 1 flavor QCD with physical quark masses. The quarkonia action was modified to account for the systematic study of the heavy-quark mass dependence. We focused on the J/ψ and Υ spectral functions and related our model to heavy quarkonia formation as a special aspect of hadron phenomenology in heavy-ion collisions at LHC.

scholarly journals Small System Collectivity in Relativistic Hadronic and Nuclear Collisions

2018 ◽  
Vol 68 (1) ◽  
pp. 211-235 ◽  
Author(s):  
James L. Nagle ◽  
William A. Zajc
Keyword(s):  
Large Hadron Collider ◽  
Nuclear Matter ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collider ◽  
Small System ◽  
Nuclear Collisions ◽  
Ion Collisions ◽  
Bulk Motion ◽  
Inviscid Hydrodynamics

The bulk motion of nuclear matter at the ultrahigh temperatures created in heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider is well described in terms of nearly inviscid hydrodynamics, thereby establishing this system of quarks and gluons as the most perfect fluid in nature. A revolution in the field is under way, spearheaded by the discovery of similar collective, fluid-like phenomena in much smaller systems including p+ p, p+ A, d+Au, and3He+Au collisions. We review these exciting new observations and their profound implications for hydrodynamic descriptions of small and/or out-of-equilibrium systems.

scholarly journals Quarkonium measurements in heavy-ion collisions with the STAR experiment

2018 ◽  
Vol 171 ◽  
pp. 18015
Author(s):  
Xinjie Huang
Keyword(s):  
Transverse Momentum ◽  
Nuclear Matter ◽  
Heavy Ion Collisions ◽  
Theoretical Calculations ◽  
Heavy Ion ◽  
Matter Effects ◽  
Nuclear Modification ◽  
Ion Collisions ◽  
Star Experiment ◽  
Nuclear Modification Factors

In these proceedings, we present the latest measurements of J/ψ and ϒ by the STAR experiment. The J/ψ and ϒ production measured in p+p collisions provide new baselines for similar measurements in Au+Au collisions, while the measurements in p+Au collisions can help quantify the cold nuclear matter effects. The J/ψ υ2 is measured in both U+U and Au+Au collisions to place constraints on the amount of J/ψ arising from recombination of deconfined charm and anti-charm pairs. Furthermore, the nuclear modification factors for ground and excited ϒ states as a function of transverse momentum and centrality are presented, and compared to those measured at the LHC as well as to theoretical calculations.

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