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arXiv 0811.3766nucl-th
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作为核-冕叠加几何效应的重离子碰撞中奇异产生的中心依赖性

Centrality dependence of strangeness production in heavy-ion collisions as a geometrical effect of core-corona superposition

F. Becattini, J. Manninen

摘要:

结果表明,在\sqrt(s)NN}= 200 GeV的Au-Au碰撞中,奇异粒子产生随中心性的变化,可以用完全化学平衡的强子气体(核)和两个碰撞核重叠区边界的核子-核子碰撞(日冕)的辐射叠加来解释。该模型很好地解释了在该能量下相对论性重离子碰撞中观察到的中心性对φ介子和奇异粒子产生的增强作用。增强主要是一个几何效应,即增加重量的核心相对于日冕更高的中心性,而奇异正则抑制的核心似乎只在非常外围的碰撞中发挥作用。这个模型,如果证实在较低的能量,将解决长期存在的问题的奇异性欠饱和的相对论重离子碰撞,参数$\gs$。此外,它将提供一个独特的工具来定位在核碰撞中的解除封闭的开始作为能量和中心性的函数,如果这是与一个完全平衡的核心的形成的开始。

英文摘要:

It is shown that data on strange particle production as a function of centrality in Au-Au collisions at \sqrt(s)_{NN}= 200 GeV can be explained with a superposition of emission from a hadron gas at full chemical equilibrium (core) and from nucleon-nucleon collisions at the boundary (corona) of the overlapping region of the two colliding nuclei. This model nicely accounts for the enhancement of phi meson and strange particle production as a function of centrality observed in relativistic heavy ion collisions at that energy. The enhancement is mainly a geometrical effect, that is the increasing weight of the core with respect to corona for higher centrality, while strangeness canonical suppression in the core seems to play a role only in very peripheral collisions. This model, if confirmed at lower energy, would settle the long-standing problem of strangeness under-saturation in relativistic heavy ion collisions, parametrized by $\gs$. Furthermore, it would give a unique tool to locate the onset of deconfinement in nuclear collisions both as a function of energy and centrality if this is to be associated to the onset of the formation of a fully equilibrated core.

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。

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