论文标题
关于剪切和旋转大厅对$λ$极化在重离子碰撞中的贡献的歧义
On Ambiguity of Definition of Shear and Spin-Hall Contributions to $Λ$ Polarization in Heavy-Ion Collisions
论文作者
论文摘要
最近，讨论了最近提出的热剪切和自旋壁对重离子碰撞中粒子极化的贡献。热剪切贡献的替代定义，即一方面的becattini-buzzegoli-palermo，另一方面是刘-yin的替代定义，在中间差异区域非常相似，而在前进速度的速度却完全不同，而在固定目标实验中以固定目标进行了测量。结果表明，在这些替代定义中，热剪切对全局极化的贡献延伸到所有动量。如果在所有动量上平均运行，则对全球极化的自旋式贡献与Liu-yin剪切的贡献相似。仅应用限制性动量接受和提升（至$λ$ rether框架）校正导致非零全球旋转式极化。如果对自旋式贡献的定义类似于Becattini-Buzzegoli-Palermo剪切剪切，那么即使没有任何接受和增强校正，全球自旋式偏振也不为零。
Recently proposed thermal-shear and spin-Hall contributions to the particle polarization in heavy-ion collisions are discussed. Alternative definitions of the thermal-shear contribution, i.e. those of Becattini-Buzzegoli-Palermo on the one hand and Liu-Yin on the other, are very similar in the midrapidity region while quite different at forward-backward rapidities, which are measured in fixed-target experiments. It is shown that the thermal-shear contribution to the global polarization with momentum averaging extended to all momenta is very different within these alternative definitions. The spin-Hall contribution to the global polarization, defined similarly to the Liu-Yin shear one, is identically zero, if averaging runs over all momenta. Only application of restrictive momentum acceptance and the boost (to $Λ$ rest frame) correction result in nonzero global spin-Hall polarization. If the spin-Hall contribution were defined similarly to Becattini-Buzzegoli-Palermo shear one, the global spin-Hall polarization would be non-zero even without any acceptance and the boost correction.
