论文标题
全球旋转对准媒介介子对重型离子碰撞中的手性磁效应的影响
Impact of globally spin-aligned vector mesons on the search for the chiral magnetic effect in heavy-ion collisions
论文作者
论文摘要
在高能重型离子碰撞中，预计手性磁效应（CME）是由核介质中夸克的手性失衡与强烈磁场的相互作用引起的，并且会沿磁场方向引起电荷分离。尽管在相对论重离子碰撞器（RHIC）和大型强子对撞机（LHC）的实验中，对CME的搜索仍在进行中，但需要对CME敏感的可观察物进行审查，以排除非CME贡献。在这项工作中，我们研究了全球旋转旋转的$ρ$介子对$γ_{112} $相关器，$ r_ {ψ_2}（δs）$相关器的影响，并通过玩具模型和多层速度传输模型（AMPT）。向量介子的全局自旋对齐可能源自重离子碰撞中的非CME机制，其特征是旋转密度矩阵的00组分，$ρ_{00} $。我们发现CME可观察结果对$ρ_{00} $显示出类似的依赖性，并且如果$ρ_{00} $ $ρ$梅森一家$ρ_{00} $比1/3更大（较小），则可以从$ρ$ -Decay Pions获得正（负）贡献。由于普斯是此类碰撞中最丰富的粒子，因此$ρ_{00} $测量值$ρ$中的测量对于对CME数据的解释至关重要。
In high-energy heavy-ion collisions, the chiral magnetic effect (CME) is predicted to arise from the interplay between the chirality imbalance of quarks in the nuclear medium and the intense magnetic field, and will cause a charge separation along the magnetic field direction. While the search for the CME is still ongoing in experiments at Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), the CME-sensitive observables need to be scrutinized to exclude the non-CME contributions. In this work, we examine the influence of globally spin-aligned $ρ$ mesons on the $γ_{112}$ correlator, the $R_{Ψ_2}(ΔS)$ correlator, and the signed balance functions, via a toy model and a multiphase transport model (AMPT). The global spin alignment of vector mesons could originate from non-CME mechanisms in heavy-ion collisions, and is characterized by the 00-component of the spin density matrix, $ρ_{00}$. We find that the CME observables show similar dependence on $ρ_{00}$, and could receive a positive (negative) contribution from $ρ$-decay pions, if the $ρ_{00}$ of $ρ$ mesons is larger (smaller) than 1/3. Since pions are the most abundant particles in such collisions, the $ρ_{00}$ measurements for $ρ$ mesons become crucial to the interpretation of the CME data.
