Exactly central heavy-ion collisions by nuclear hydrodynamics

Abstract

We study the dynamics of heavy-ion collisions using the hydrodynamical description and focus our attention on the head-on collisions which provide the most favorable case for such a description. Angular distributions and energy distributions were obtained for various combinations of projectiles and targets of equal and unequal masses in the energy range from 50 to 400 MeV per projectile nucleon. It is found that regions of high density (the shock regions) are formed during the collisions and that the angular and energy distributions for many of these collisions have prominent features. In the collision of a small projectile with a heavy target, there is the forward angular peak of slow dissociated particles which represent much of the projectile nuclear matter stopped in the larger target nucleus, in addition to the nucleons from the expansions of the shock region. There is the side angular peak corresponding to the sidesplash of the target nuclear matter due to the impact of the projectile. There is also the backward angular peak due to the expansion of the shock region into the backward direction. In the collision of two equal nuclei, there are only the forward angular peak and the side angular peak. The effects of viscosity and thermal conductivity are investigated and found to affect the angular and energy distributions of the reaction products.NUCLEAR REACTIONS Heavy-ion reactions, nuclear hydrodynamics, $^{20}\mathrm{Ne}$ +$^{197}\mathrm{Au}$ and $^{208}\mathrm{Pb}$+$^{208}\mathrm{Pb}$ at 50, 100, 250, and 400 MeV per projectile nucleon. Nuclear viscosity and thermal conductivity.