The global spin alignment of the vector meson has been observed in relativistic heavy ion collisions, but its theoretical origin is still on hot debates. Here we propose to apply the light front framework to explain this phenomenon since the light front form explicitly describes the hadron spin including both the quark spin and the orbital angular momentum. After applying the light front spinor, we find that the spin alignment in the polarization of vector mesons with can be naturally manifested and in particular, the obtained spin alignment for meson is in good agreement with the experimental data. This implies that to explain the spin alignment it is important to properly include the contribution from the gluon interactions that are presented in terms of the orbital angular momentum of the hadron bound state.

中文翻译：

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矢量介子与轻前夸克的自旋排列


在相对论性重离子碰撞中已经观察到了矢量介子的全局自旋排列，但其理论起源仍然存在争议。在这里，我们建议应用光锋框架来解释这种现象，因为光锋形式明确描述了强子自旋，包括夸克自旋和轨道角动量。应用光前旋量后，我们发现矢量介子偏振中的自旋排列可以自然地表现出来，特别是所获得的介子自旋排列与实验数据吻合得很好。这意味着为了解释自旋排列，正确地包括以强子束缚态的轨道角动量表示的胶子相互作用的贡献是很重要的。