Asymmetry of velocity distributions in peripheral collisions at Fermi energies
T. I. Mikhailova, B. Erdemchimeg, G. Kaminski, A. G. Artyukh, M. Colonna, M. Di Toro, I. N. Mikhailov, Yu. M. Sereda, H. H. Wolter
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13 pages, 5 figures, talk delivered at the International Meeting on Nuclear Spectroscopy and Nuclear Structure (Nucleus 2008), Moscow (Russia), June 23--27, 2008
Asymmetry of the velocity distributions of projectile like fragments produced in heavy-ion collisions is discussed. The calculations made in transport model approach (the solution of Vlasov kinetic equation with the collisions term) are compared with experimental data for the reactions $^{22}Ne$ ($40 A\cdot$MeV) + $^{9}$Be and $^{18}$O ($35 A\cdot$MeV) + $^9$Be ($^{181}$Ta) at forward angles. It is found that the velocity distributions appear to be composed of two contributions: a direct component centered at beam velocity and a dissipative component at lower energies, leading to an asymmetry of the velocity distributions. The direct component is interpreted empirically in the Goldhaber model, and the widths and centroids of the distributions are extracted. The remaining dissipative (also called deep-inelastic) contributions are then well described by the transport calculations. It is shown that the ratio of yields of direct and dissipative contributions, which determines the asymmetry of velocity distribution, depends on the shape of the deflection function.
IMF isotopic properties in semi-peripheral collisions at Fermi energies
本文研究了47 AMeV半周边碰撞中中子和质子沿碎裂路径的动力学行为：58 Fe +58 Fe（电荷不对称，N/Z = 1.23）和58 Ni +58 Ni（电荷对称，N/Z = 1.07）。我们观察到在电荷对称的58 Ni +58 Ni系统中也发生了同位旋动力学过程，这可能产生更多的非对称碎片。观察到颈部碎片的中子富集，这是由于平衡前发射和“同位旋迁移”现象之间的相互作用。这两种效应都依赖于状态方程（EoS）对称项。这一点是通过比较两种不同选择的对称性能量密度依赖性所获得的结果来说明的。提出了新的关联观测量，用以研究反应机理和同位旋动力学。
Even-by-event hydrodynamical simulations for $\sqrt{s}_{NN}$=200 GeV Au+Au collisions and the correlation between flow coefficients and initial asymmetry measures
Electromagnetic interaction of low transverse momentum electrons and positrons with heavy nuclei in ultra-peripheral ultra-relativistic heavy-ion collisions
