Isospin transport ratio is a powerful method to estimate the neutron-proton (n-p) equilibration in heavy-ion collisions, and extensively used to obtain information on the asy-stiffness of the nuclear Equation of State. In fact such a ratio is expected to bypass any perturbations introducing a linear transformation of the chosen observable. In particular, it is supposed to overcome contributions due to emission, either of dynamical or statistical nature, from the primary fragments formed during the collisions. In this paper we explore the validity of this assumption, looking at the quasi-projectile n-p ratio ($N/Z$) in peripheral and semi-peripheral events for Ca+Ca reactions at 35, simulated via the Antisymmetrized Molecular Dynamics transport model, coupled to different statistical decay codes. The statistical de-excitation of the primary fragments introduces a linear transformation at relatively high excitation energies (above 2) when the residue approaches the Evaporation Attractor Line, while some effect is produced at lower excitation energies due to the occurrence of some non-linearities. As for fast emissions after the end of the projectile-target interaction it is shown that they introduce a non-linear transformation too.

中文翻译：

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快速排放和统计消灭对同位旋输运比的影响

等位旋输运比是一种估算重离子碰撞中的中子-质子（np）平衡的有力方法，并广泛用于获得有关核状态方程的刚度的信息。实际上，期望该比率绕过引入所选观测值的线性变换的任何扰动。特别地，应该克服在碰撞过程中形成的主要碎片由于发射而造成的动力或统计性质的贡献。在本文中，我们通过研究准射弹np比（$ñ/ž$）在35岁时发生的Ca + Ca反应的外围和半外围事件中，通过反对称分子动力学传输模型进行了模拟，并与不同的统计衰减代码耦合。当残渣接近蒸发吸引线时，主要片段的统计去激会在较高的激发能（大于2）处引入线性变换，而由于某些非线性的发生，在较低的激发能下会产生一些影响。至于弹丸-目标相互作用结束后的快速发射，表明它们也引入了非线性变换。