论文标题
使用爱丽丝探测器搜索手性磁效应
Search for the Chiral Magnetic Effect with the ALICE detector
论文作者
论文摘要
在非中央重型离子碰撞中，不参与相互作用的观众质子会产生强烈的磁场。这些场的强度允许根据QCD的假设特性来测试效果。所谓的拓扑结构的存在会导致带有净手性的域。结合上述磁场，它们可能会引起碰撞中产生的颗粒的电荷分离。该电荷分离称为手性磁效应（CME），可以通过带电的粒子角相关性进行测量。 $γ_{1,1} $相关器的测量值对CME敏感，在$ \ sqrt {s _ {\ mathrm {\ Mathrm {nn}}}} = 5.02 $ tev以及xe-xe Collisision in xe-xe Collisions in $ \ sqrt {s _ {s _ {s _ {s _ { $ \ sqrt {s _ {\ mathrm {nn}}}} = 5.44 $ tev。发现它们在相对符号和同符号对之间具有显着的电荷依赖性。这种行为与类似CME的信号一致。但是，在Xe-Xe碰撞中测量了与任何对称平面无关的电荷相关性（即背景）无关的电荷相关性，并显示出显着的电荷依赖性。这样可以防止对$γ_{1,1} $相关器的明确解释。必须将CME贡献限制为$γ_{1,1} $相关器的新方法。
In non-central heavy-ion collisions, spectator protons that do not participate in the interaction create strong magnetic fields. The strength of these fields allows testing an effect based on the hypothesized properties of QCD. The presence of so-called topological configurations can give rise to domains that carry net chirality. Coupled with the aforementioned magnetic fields, they may induce a charge separation of the particles generated in the collisions. This charge separation is called the Chiral Magnetic Effect (CME) and can be measured through charged-particle angular correlations. Measurements of the $γ_{1,1}$ correlator, which is sensitive to the CME, are shown for Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV as well as for Xe--Xe collisions at $\sqrt{s_{\mathrm{NN}}} = 5.44$ TeV. These are found to have a significant charge dependence between opposite-sign and same-sign charge pairs. This behavior is consistent with a CME-like signal. However, the $δ_{1}$ correlator, which measures charge correlations unrelated to any symmetry plane (i.e. background), was measured in Xe--Xe collisions and also shows a significant charge dependence. This prevents a clear interpretation of the $γ_{1,1}$ correlator. Novel methods to constrain the CME contribution to the $γ_{1,1}$ correlator are necessary.
