Collective Flow In Intermediate Energy Heavy Ion Collisions

Ions are atoms or molecules stripped of their electrons, so they can be accelerated by electric fields. They can be made to hit each other with low energy, intermediate energy, high energy, or very high energy; each energy range seeks to investigate different aspects of hadronic physics. Intermediate-energy heavy ion collisions explore the nuclei far from stability valley, the incompressibility of nuclear matter, the liquid-gas phase transition in nuclear environment, the symmetry energy far from the normal density, and other phenomena. This has been an active field of research for last four decades.This is a book for entrants in the field. It is suitable as a companion book in a graduate course. For practitioners in the field it will be useful as a reference.

The Equation of State (EoS) of asymmetric nuclear matter has been explored through the study of mid-rapidity fragment dynamics from the 35 MeV/u70Zn+70Zn, 64Zn+64Zn, and 64Ni+64Ni systems. The experimental data was collected at the Texas A & M Cyclotron Institute using the 4[pie] NIMROD-ISiS array, which provided both event characterization and excellent isotopic resolution of charged particles. The transverse collective flow was extracted for proton, deuteron, triton, 3He, alpha, and 6He particles. Isotopic and isobaric effects were observed in the transverse flow of the fragments. In both cases, the transverse flow was shown to decrease with an increasing neutron content in the fragments. The (N/Z)sys dependence of the transverse flow and the difference betwen the triton and 3He flow were shown to be sensitive to the density dependence of the symmetry energy using the stochastic mean-field model. A stiff parameterization of Esym(p) was found to provide better agreement with the experimental data. The transverse flow for intermediate mass fragments (IMFs) was investigated, providing a new probe to study the nuclear EoS. A transition from the IMF flow strongly depending on the mass of the system, in the most violent collisions, to a dependence on the charge of the system, for the peripheral reactions, was observed. Theoretical simulations were used to show that the relative differences in the IMF flow are sensitive to the density dependence of the symmetry energy. The best agreement between the experiment and theory was achieved with a stiff Esym(p). A new method was developed in which correlations between the projectile-like and mid-rapidity fragments were examined using a scaled flow. Theoretical simulations were used to show that the scaled flow of the particles was connected to their average order of emission. The experimental results suggest that the mid-rapidity region is preferentially populated with neutron-rich light charged particles and the Z=3-4 IMFs at a relatively early stage in the collision. This work presents additional constraints on the nuclear EoS and insight into the mid-rapidity dynamics observed in Fermi energy heavy-ion collisions.

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 text book deals with many issues of nuclear reactions in contest with the heavy-ion collisions at intermediate energies. The main issues discussed in the book are Multifragmentation, elliptical flow, nuclear stopping and symmetry energy. These phenomenas can be compared with the happenings in the universe such as Supernova Explosion, Quark Gluon Plasma, Liquid Gas Phase transition, which were the basic processes at the time of expansion of the universe. Ultimately, the study of these phenomenas has made this book highly important and interesting for the researchers as well as master students working in the field of intermediate energies. In addition to this, the determination of symmetry energy for asymmetric nuclear matter, which is the burning topic in the present day research, is also explored in the present version of the book. In conclusion, the matter published in the book will give the readers the detailed analysis of the nature of the hadronic matter, which is the ultimate goal of all the theoretical as well as experimental nuclear physics collaborations throughout the world.