Stochastic multi-fluid models for intermediate-energy heavy-ion collisions

Abstract

models describe an average evolution of an ensemble of systems. Therefore, these "molecular chaos assumption" in the derivation of such kinetic equations, these are neglected in all these single-particle models. As is evident, e.g., from the Many-body correlations, other than those leading to the binary collision term, models have the great advantage of being fast numerically solvable [14, 15].the description of gross properties of the phase-space distribution, these multi-fluid one obtains a closed set of equations for the collective variables. By keeping only relevant collective quantities. Using local equilibrium distributions for each fluid, multi-fluid models the local momentum distribution is parametrized by a set of models have been developed for describing nuclear collisions [2, 3,14, 15]. In these As an alternative to the simulations by kinetic equations, mean-field multi-iiuid been recently applied to heavy-ion collisions at intermediate energies [11,12,13].Uehling-Uhlenbeck (BUU) type [1, 2, 3, 4,5,6, 7,8,9, 10]. Such equations have self-consistent mesonic mean fields and a binary collision term of the Boltzmann space distribution function which is determined by a transport equation containing In the semi-classical limit the Wigner function reduces to a single-particle phaseWigner transform (Wigner function) rather than by its many-body density matrix. transport models the system is represented by its one-body density matrix or its single-particle transport models based on effective quantum-field theories. In these Many aspects of nuclear collisions can be described in terms of relativistic dom can be naturally performed according to refs. [2, 3, l4, 15, 23] OCR Output *A generalization to inelastic interactions and to an explicit treatment of isospin degrees of free we obtain a stochastic BUU-type equation the nucleon spin-isospin degeneracy factor, respectively. In the semiclassical limit induce fluctuations by propagating correlations in the phase space. These two the momentum distribution of the constituent particles and, in addition, (ii) they dynamical evolution of a system: they produce dissipation by randomizing the main results of the model. Binary collisions play a twofold role during the effective-field theory was presented in ref.[22]. Here we give a brief survey and A derivation of the relativistic BLE in the framework of the Walecka-type

Anisotropic hydrodynamic modeling of 2.76 TeV Pb-Pb collisions

“…two-and three-fluid models, similar to what has been done by the Los Alamos [85,86], Kurchatov Institute [87][88][89], Frankfurt [90][91][92][93][94], and GSI [95][96][97][98][99][100] groups. Along these lines, there have already been prior anisotropic hydrodynamics studies which have considered multi-component fluids with explicit quark and gluon components [101,102]; however, to the best of our knowledge there have thus far not been any attempts to do this in the context of multicomponent hadronic fluids.…”

Recent Progress in Quantum Hadrodynamics

“…A covariant Boltzmann-Uehling-Uhlenbeck (BUU) approach, the basic ideas of which have been presented above, is developed in [Bl88a,La90,Ma92,Ma94a] and applied in [Bl89,Bl91,Ko90,Ko91]. Relativistic transport coefficients are discussed in [Ha93b,Ay94,Mo94].…”