发表机构
School of Physics and Astronomy, Sun Yat-sen University（中山大学物理学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出色磁场各向异性涨落产生矢量介子自旋排列的机制，并应用于重离子碰撞中J/ψ自旋排列，发现两种来源均导致负自旋排列。
AI 中文摘要
自旋关联被认为对矢量介子自旋排列有重要贡献。在本工作中，我们研究了通过夸克-胶子等离子体中色磁场涨落产生自旋关联的机制。我们证明，各向异性涨落通常会导致有限的矢量介子自旋排列。我们研究了两种各向异性色磁场涨落的来源：一种源于矢量介子相对于介质的运动，这使得介质中的各向同性涨落在介子静止系中变得各向异性；另一种源于QGP剪切流通过粘性修正对色磁场涨落的影响。我们发现这两种修正都对磁标度敏感。我们将该机制应用于研究重离子碰撞中J/ψ的自旋排列。在Bjorken流模拟QGP演化的条件下，我们从两种来源都获得了负的自旋排列，其中剪切诱导的贡献在数值上相对于运动诱导的贡献被抑制。
英文摘要
Spin correlations are believed to contribute significantly to vector-meson spin alignment. In this work, we study the generation of spin correlations through fluctuations of the chromomagnetic field in the quark-gluon plasma. We show that anisotropic fluctuations generically lead to finite vector-meson spin alignment. We study two sources of anisotropic chromomagnetic-field fluctuations: one arises from the motion of a vector meson relative to the medium, which makes isotropic fluctuations in the medium anisotropic in the meson rest frame; the other arises from QGP shear flow through viscous corrections to the chromomagnetic field fluctuations. We find both corrections to be sensitive to magnetic scale. We apply the mechanism to study spin alignment of J/ψ in heavy ion collisions. With QGP evolution modeled by Bjorken flow, we obtain negative spin alignment from both sources, with the shear induced contribution numerically suppressed compared to the motion induced contribution.
Comments24pages,3figures
