论文标题
在两个具有变形且富含中子的核结构的等轴体之间的碰撞中搜索手性磁效应
Search for the chiral magnetic effect in collisions between two isobars with deformed and neutron-rich nuclear structures
论文作者
论文摘要
被认为具有相同背景和不同磁场的伊索巴尔碰撞为验证相对论重离子碰撞中的手性磁效应（CME）提供了机会。但是，RHIC-StAR ISOBAR实验的第一个结果未观察到CME信号，而是发现背景在$ _ {44}^{96} {96} \ textrm {Ru}+_ {44} $ _ {40}^{96} \ textrm {zr}+_ {40}^{96} {96} \ textrm {zr} $ collisions。我们使用mutiphase转运模型测试了由不同的核变形或核结构效应产生的18例木材 - 撒克逊参数设置。我们发现七个病例可以通过Star实验得出的三个参考比率合理地重现。考虑到Halo-Type中子皮肤结构和类似CME的电荷分离，我们证明，如果CME在Isobar Collisions中，CME的存在或不存在CME，则很难可观察到CME的存在或不存在CME的存在或不存在CME的存在。这是因为最终状态相互作用显着削弱了初始CME信号，从而导致CME可观察到CME强度的非线性敏感性。因此，需要更敏感的可观察力来搜索等轴碰撞中可能的小CME信号。
Isobar collisions which were thought to have the same background and different magnetic fields provide an opportunity to verify the chiral magnetic effect (CME) in relativistic heavy-ion collisions. However, the first result from the RHIC-STAR isobar experiment did not observe the CME signal, but discovered that the backgrounds are different between $_{44}^{96}\textrm{Ru}+_{44}^{96}\textrm{Ru}$ and $_{40}^{96}\textrm{Zr}+_{40}^{96}\textrm{Zr}$ collisions. We test eighteen cases of Woods-Saxon parameter settings resulting from different nuclear deformation or nuclear structure effects using a mutiphase transport model. We find out that seven cases can reasonably reproduce three reference ratios measured by the STAR experiment. Considering both the halo-type neutron skin structure and CME-like charge separation, we demonstrate that it is difficult for the CME observables ($Δδ$, $Δδ$ ratio, $Δγ$ and $Δγ$ ratio) to distinguish the presence or absence of the CME, if the CME strength is weak in isobar collisions. It is because the final state interactions significantly weaken the initial CME signal, resulting in non-linear sensitivities of the CME observables to the CME strength. Therefore, more sensitive observables are required to search for the possible small CME signal in isobar collisions.
