发表机构
Institute of Frontier and Interdisciplinary Science, Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University; School of Physics and Technology, University of Jinan（山东大学前沿交叉科学研究院，粒子物理与粒子辐照教育部重点实验室; 济南大学物理科学与技术学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究探究非极化pp碰撞中背对背胶子对的极化关联，发现q\bar{q}湮灭产生的胶子对为最大纠缠贝尔态，gg→gg道的为可分态但仍有11%线性极化关联，可通过能量 correlator的cos2ΔΦ调制提取该关联。
AI 中文摘要
我们研究了非极化pp碰撞中背对背胶子对的极化关联并计算其密度矩阵。对于通过q\bar{q}湮灭产生的胶子对，其线性极化关联显著，当在q\bar{q}静止系中末态胶子垂直于束流方向发射时，线性极化关联甚至可达1。结合其螺旋度在不同散射角下仍保持最大关联的事实，该胶子对系统在此构型下处于最大纠缠的贝尔态。相比之下，对于gg→gg道，螺旋度和线性极化关联均被显著抑制，产生可分态，但在中心散射处仍保留约11%的可观线性极化关联。利用能量 correlator的各向异性，我们证明可从cos2ΔΦ调制中提取胶子对的线性极化关联。
英文摘要
We investigate the polarization correlation of back-to-back gluon pairs in unpolarized $pp$ collisions and compute their density matrix. For gluon pairs produced through $q\bar{q}$ annihilation, the linear polarization correlation is sizable, even reaching unity when the final-state gluons are emitted perpendicular to the beam direction in the $q\bar{q}$ rest frame. Combining with the fact that their helicity remains maximally correlated across different scattering angle, the gluon pair system thus resides in a maximally entangled Bell state in this configuration. In contrast, for the $gg\to gg$ channel, both the helicity and linear polarization correlations are considerably suppressed, producing a separable state. Nonetheless, it still retains an appreciable linear polarization correlation of about $11\%$ at central scattering in unpolarized collisions. The linearly polarization correlation of the back-to-back gluon pair can further increase when the incoming gluons are circularly polarized. Employing the anisotropy of energy correlators, we demonstrate that the linear polarization correlation of gluon pairs can be extracted from the $\cos 2ΔΦ$ modulation.
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