arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0811.1918nucl-thnucl-ex
收藏

相对论性重离子碰撞中热源和直接源发射的相互作用

Interplay of the emission from thermal and direct sources in relativistic heavy ion collisions

Piotr Bozek

发表信息：
Phys. Rev. C 79, 054901 (2009)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

讨论了超相对论性重离子碰撞产生的源分离成热化致密核和由独立核子-核子碰撞组成的外地幔的问题。在200 GeV的Au-Au碰撞中产生的K介子、质子和反质子的横质谱中发现了这种双组分图像的证据。的热和直接源的大小的估计进行比较的模型分离的相互作用区成一个核心和日冕，根据参与者的密度或碰撞的数量。的小尺寸，热化的核心的动力学建模的后果进行了说明。与致密核相对应的新的初始条件导致流体动力膨胀火球的方位不对称性增强，压力梯度也增大。2+1维流体动力学模拟从相互作用区域中的所有物质或从源的致密热部分开始。我们发现更快的横向扩展和更强的椭圆流的致密核心的初始条件。对于不同的碰撞参量，我们发现源的热部分的谱非常相似，并且只增加从日冕中核子-核子碰撞直接发射的粒子，实验观察到的谱随碰撞参量增加而软化的现象被再现。对于从分离成核和日冕的源发射的粒子，椭圆流更强。

英文摘要：

The separation of the source created in ultrarelativistic heavy-ion collisions into a thermalized dense core and an outer mantle consisting of independent nucleon-nucleon collisions is discussed. Evidence for such a two component picture is found in transverse mass spectra of kaon, protons and antiprotons produced in Au-Au collisions at 200GeV. Estimates of the sizes of the thermal and direct sources are compared to models separating the interaction zone into a core and a corona, according to the density of participants or to the number of collisions. Consequences for the modeling of the dynamics of the small size, thermalized core are described. New initial conditions corresponding to the dense core lead to a stronger azimuthal asymmetry of the hydrodynamically expanding fireball, pressure gradients also increase. 2+1-dimensional hydrodynamic simulations are presented starting from all the matter in the interaction region or from the dense, thermal part of the source. We find faster transverse expansion and stronger elliptic flow for dense core initial conditions. For different impact parameters we find very similar spectra of the thermal part of the source and only adding particles emitted directly from nucleon-nucleon collisions in the corona the experimentally observed softening of the spectra with increasing impact parameter is reproduced. The elliptic flow is stronger for particles emitted from a source separated into a core and a corona.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑