论文标题
相对论重离子碰撞中的局部自旋极化
Local spin polarizations in relativistic heavy ion collisions
论文作者
论文摘要
基于对无质性手性费米子的广泛侧跳形式主义，自然考虑了两种手性费米子散射中的旋转轨道耦合以及旋转的手性效率在旋转的手性费米子中，我们已经开发了一种协方压和总的角度势力保守的手动流体传输模型，以研究全局和研究本地的局部元素。对于盒子中随机旋转方向和有限涡度的无质量夸克系统，我们已经证明该模型可以精确地保存系统的总角动量，并动态生成来自热平衡夸克物质预期的夸克旋转极化。使用该模型研究相对论重离子碰撞中的自旋极化，我们发现局部夸克自旋极化在很大程度上取决于参考框架，该参考框是由手性涡旋效应引起的非平凡轴向电荷分布对它们进行评估的。我们进一步表明，由于对夸克自旋极化的异常轨道或侧面跳跃贡献，因此在中静息框架中计算出的局部夸克极化在定性上与实验中测得的lambda超数的局部极化一致。
Based on a generalized side-jump formalism for massless chiral fermions, which naturally takes into account the spin-orbit coupling in the scattering of two chiral fermions and the chiral vortical effect in a rotating chiral fermion matter, we have developed a covariant and total angular momentum conserved chiral transport model to study both the global and local polarizations of this matter. For a system of massless quarks of random spin orientations and finite vorticity in a box, we have demonstrated that the model can exactly conserve the total angular momentum of the system and dynamically generate the quark spin polarization expected from a thermally equilibrated quark matter. Using this model to study the spin polarization in relativistic heavy-ion collision, we have found that the local quark spin polarizations depend strongly on the reference frame where they are evaluated as a result of the nontrivial axial charge distribution caused by the chiral vortical effect. We have further shown that because of the anomalous orbital or side-jump contribution to the quark spin polarization, the local quark polarizations calculated in the medium rest frame are qualitatively consistent with the local polarizations of Lambda hyperons measured in experiments.
