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 ◽  
...  

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.

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 171
Author(s):  
Peter Senger

The poorly known properties of high-density strongly-interacting matter govern the structure of neutron stars and the dynamics of neutron star mergers. New insight has been and will be gained by astronomical observations, such as the measurement of mass and radius of neutron stars, and the detection of gravitational waves emitted from neutron star mergers. Alternatively, information on the Nuclear Matter Equation-of-State (EOS) and on a possible phase transition from hadronic to quark matter at high baryon densities can be obtained from laboratory experiments investigating heavy-ion collisions. Detector systems dedicated to such experiments are under construction at the “Facility for Antiproton and Ion Research” (FAIR) in Darmstadt, Germany, and at the “Nuclotron-based Ion Collider fAcility” (NICA) in Dubna, Russia. In heavy-ion collisions at these accelerator centers, one expects the creation of baryon densities of up to 10 times saturation density, where quark degrees-of-freedom should emerge. This article reviews the most promising observables in heavy-ion collisions, which are used to probe the high-density EOS and possible phase transition from hadronic to quark matter. Finally, the facilities and the experimental setups will be briefly described.


Particles ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 320-335
Author(s):  
Peter Senger

The future “Facility for Antiproton and Ion Research” (FAIR) is an accelerator-based international center for fundamental and applied research, which presently is under construction in Darmstadt, Germany. An important part of the program is devoted to questions related to astrophysics, including the origin of elements in the universe and the properties of strongly interacting matter under extreme conditions, which are relevant for our understanding of the structure of neutron stars and the dynamics of supernova explosions and neutron star mergers. The Compressed Baryonic Matter (CBM) experiment at FAIR is designed to measure promising observables in high-energy heavy-ion collisions, which are expected to be sensitive to the high-density equation-of-state (EOS) of nuclear matter and to new phases of Quantum Chromo Dynamics (QCD) matter at high densities. The CBM physics program, the relevant observables and the experimental setup will be discussed.


2010 ◽  
Vol 19 (07) ◽  
pp. 1259-1313 ◽  
Author(s):  
FRANCESCA SAMMARRUCA

We review a variety of theoretical and experimental investigations aimed at improving our knowledge of the nuclear matter equation of state. Of particular interest are nuclear matter extreme states in terms of density and/or isospin asymmetry. The equation of state of matter with unequal concentrations of protons and neutrons has numerous applications. These include heavy-ion collisions, the physics of rare, short-lived nuclei and, on a dramatically different scale, the physics of neutron stars. The "common denominator" among these (seemingly) very different systems is the symmetry energy, which plays a crucial role in both the formation of the neutron skin in neutron-rich nuclei and the radius of a neutron star (a system 18 orders of magnitude larger and 55 orders of magnitudes heavier). The details of the density dependence of the symmetry energy are not yet sufficiently constrained. Throughout this article, our emphasis will be on the importance of adopting a microscopic approach to the many-body problem, which we believe to be the one with true predictive power.


1994 ◽  
Vol 09 (13) ◽  
pp. 1151-1157 ◽  
Author(s):  
C. HARTNACK ◽  
J. AICHELIN ◽  
H. STÖCKER ◽  
W. GREINER

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.


Particles ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 214-226
Author(s):  
Peter Senger

The “Facility for Antiproton and Ion Research” (FAIR) in Darmstadt, Germany, and the “Nuclotron-based Ion Collider Facility” (NICA) in Dubna, Russia, are two accelerator centers under construction. FAIR will provide beams and experimental setups to perform forefront research in hadron, nuclear, atomic, and plasma physics, as well as in radiation biology and material science. At NICA, a unique research program on nuclear matter and spin physics will be conducted. Both facilities will execute experiments to explore the properties of QCD matter at neutron star core densities, in order to study the high-density equation of state, and to shed light on the quark degrees-of-freedom emerging in QCD matter at high densities. The research programs will be performed at FAIR with the CBM experiment, and at NICA with the MPD setup at the collider, and with the BM@N experiment at the Nuclotron. These three experiments are complementary, with respect to the beam energy. The physics programs and the relevant experimental observables will be discussed.


2021 ◽  
Vol 52 (4) ◽  
pp. 544-548
Author(s):  
E. E. Zabrodin ◽  
A. S. Botvina ◽  
L. V. Bravina ◽  
G. Kh. Eyyubova ◽  
Yu. B. Ivanov ◽  
...  

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1852
Author(s):  
Larissa V. Bravina ◽  
Kyrill A. Bugaev ◽  
Oleksandr Vitiuk ◽  
Evgeny E. Zabrodin

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¯.


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