A prominent goal within the field of modern heavy-ion collisions is to uncover the phase diagram of QCD. Studies of the properties of systems created in heavy-ion collisions strongly suggest that a new state of matter described by quark and gluon degrees of freedom, the quark-gluon plasma, is created when nuclei are collided at very high-energies. Consequently, the QCD phase diagram may contain a rich structure in regions currently accessible to heavy-ion experiments, including a possible critical point where the transformation between hadronic and partonic matter changes from a smooth crossover to a first-order phase transition. Whether this is the case will have to be born out through a combination of experimental analyses and state-of-the-art simulations of heavy-ion collisions. We present a mean-field model of the dense nuclear matter equation of state designed for use in computationally demanding hadronic transport simulations. Our approach, based on the relativistic Landau Fermi-liquid theory, allows us to construct a family of equations of state spanning a wide range of possible bulk properties of dense QCD matter. For the application to simulations of heavy-ion collisions at intermediate beam energies, and in particular having in mind studies centered on probing the regions of the QCD phase diagram most relevant to the search for the QCD critical point, we further present and discuss parametrizations of the developed equation of state describing dense nuclear matter with two phase transitions: the known nuclear-liquid gas phase transition in ordinary nuclear matter, with its experimentally observed properties, and a postulated phase transition at high temperatures and high baryon number densities, meant to model the QCD phase transition from hadronic to quark and gluon degrees of freedom. We implement the developed model in the hadronic transport code SMASH, and show that the resulting dynamic behavior reproduces theoretical expectations for the thermodynamic properties of the system based on the underlying equation of state. In particular, we discuss simulations of systems initialized in regions of the phase diagram affected by the conjectured QCD critical point, and we demonstrate that they reproduce effects due to critical behavior. Specifically, we show that pair distribution functions calculated from hadronic transport simulation data are consistent with theoretical expectations based on the second-order cumulant ratio, and can be used as a signature of crossing the phase diagram in the vicinity of a critical point. Through this, we validate the use of hadronic transport codes as a tool to study signals of a phase transition in dense nuclear matter. We additionally present a novel method that may enable a measurement of the speed of sound and its derivative with respect to the baryon number density in heavy-ion collisions. The devised approach is based on a connection between the speed of sound and the cumulants of the net baryon number, which in the context of the search for the QCD critical point are given considerable attention due to their potential to signal critical fluctuations. We confirm the applicability of the proposed method in two models of dense nuclear matter, including the parametrization of the equation of state developed in this work. Application of our approach to available experimental data implies that the derivative of the speed of sound is non-monotonic in systems created in collisions at intermediate to low energies, which in turn may be connected to non-trivial features in the underlying equation of state.

This book gives an introduction to main ideas used in the physics of ultra-relativistic heavy-ion collisions. The links between basic theoretical concepts (discussed gradually from the elementary to more advanced level) and the results of experiments are outlined, so that experimentalists may learn more about the foundations of the models used by them to fit and interpret the data, while theoreticians may learn more about how different theoretical ideas are used in practical applications. The main task of the book is to collect the available information and establish a uniform picture of ultra-relativistic heavy-ion collisions. The properties of hot and dense matter implied by this picture are discussed comprehensively. In particular, the issues concerning the formation of the quark-gluon plasma in present and future heavy-ion experiments are addressed.

The non-equilibrium equation of state is found in the approximation of the functional on the local density, and its application to the description of the emission of protons and pions in heavy ion collisions is considered. The non-equilibrium equation of state is studied in the context of the hydrodynamic approach. The compression stage, the expansion stage, and the freeze-out stage of the hot spot formed during the collisions of heavy ions are considered. The energy spectra of protons and subthreshold pions produced in collisions of heavy ions are calculated with inclusion of the nuclear viscosity effects and compared with experimental data for various combinations of colliding nuclei with energies of several tens of MeV per nucleon.

Introduction to Relativistic Heavy Ion Collisions László P. Csernai University of Bergen, Norway Written for postgraduates and advanced undergraduates in physics, this clear and concise work covers a wide range of subjects from intermediate to ultra-relativistic energies, thus providing an introductory overview of heavy ion physics. The reader is introduced to essential principles in heavy ion physics through a variety of questions, with answers, of varying difficulty. This timely text is based on a series of well received lectures given by Professor L. Csernai at the University of Minnesota, and the University of Bergen, where the author is based.

This book offers the unique possibility of tackling the problem of hadronic deconfinement from different perspectives. After general introductions to the physical issues, from both the theoretical and the experimental point of view, the book presents the most recent expertise on field theory approaches to the QCD phase diagram, many-body techniques and applications, the dynamics of phase transitions, and phenomenological analysis of relativistic heavy ion collisions.One of the major goals of this book is to promote interchange among those fields of research, which have traditionally been cultivated by different communities of physicists. The contributions in the book help in obtaining deep comprehension of this new state of matter, a system of deconfined quarks and gluons. At the same time the book offers a few examples of how the seeds of the deconfined state are looked for in the phenomenological analysis of the observables measured in relativistic heavy ion collisions. The main topics are dealt with in a pedagogical style, suitable for beginners as well as experienced researchers.

Papers of the June 1989 meeting in Beijing by the China Center of Advanced Science and Technology. This small book covers nucleus- nucleus collisions, states of the vacuum, and highly relativistic heavy ions in the experimental realm. Theoretical papers deal with quark-gluon plasma, and relativistic heavy ion collisions. Annotation copyrighted by Book News, Inc., Portland, OR