Dynamics Of Nuclear Matter Research Articles

Homogenization of dissipative, noisy, Hamiltonian dynamics

We study the dynamics of a class of Hamiltonian systems with dissipation, coupled to noise, in a singular (small mass) limit. We derive the homogenized equation for the position degrees of freedom in the limit, including the presence of a noise-induced drift term. We prove convergence to the solution of the homogenized equation in probability and, under stronger assumptions, in an Lp-norm. Applications cover the overdamped limit of particle motion in a time-dependent electromagnetic field, on a manifold with time-dependent metric, and the dynamics of nuclear matter.

Effective-interaction approach to the Fermi hard-sphere system

The formalism based on correlated basis functions and the cluster expansion technique has been recently employed to derive an effective interaction from a realistic nuclear hamiltonian. To gauge the reliability of this scheme, we perform a systematic comparison between the results of its application to the Fermi hard-sphere system and the predictions obtained from low-density expansions, as well as from other many-body techniques. The analysis of a variety of properties, including the ground state energy, the effective mass and the momentum distribution, shows that the effective interaction approach is remarkably accurate, thus suggesting that it may be employed to achieve a consistent description of the structure and dynamics of nuclear matter in the density region relevant to astrophysical applications.

Probing Longitudinal Dynamics at RHIC

Particle production of charged hadrons in Au+Au collisions at \(\sqrt {s_{NN} } = 200\) GeV bas been studied as a function of rapidity by the BRAHMS Collaboration at RHIC. Selected recent results are presented with emphasis on longitudinal dynamics of particle production. The rapidity dependence of particle production imposes more stringent constraints on theoretical models describing dynamics of nuclear matter created by high-energy heavy ion collisions.

Facilities and Methods: Dielectron Spectrometry with Hades

The study of hot and dense nuclear matter by means of relativistic heavy ion collisions is nowadays one of the main topics of heavy ion physics. As the incident kinetic energy increases well above the Coulomb barrier, the nuclear shell structure becomes less and less relevant; up to 30 A MeV, collective states of nuclei still play an important role. Beyond the Fermi energy, the scenario evolves toward nuclear matter dynamics (Figure 1). Within such a scenario we try to understand the nuclear matter behavior in terms of an equation of state that, connecting variables such as pressure, temperature, and density could provide an explanation to the multi-fragmentation of the colliding nuclei as a liquid-gas phase transition.

ON THE STABILIZATION OF A VISCOUS BAROTROPIC SELF-GRAVITATING MEDIUM WITH A NONMONOTONE EQUATION OF STATE

We consider the compressible barotropic Navier–Stokes system in one dimension, with a nonmonotone equation of state and self-gravitation. We solve an associated "fixed-free" boundary problem and prove asymptotic properties of the unique globally defined solution for large time. We also comment on a related model of quantum fluid describing the dynamics of nuclear matter with zero temperature and Coulomb effects.