Implication of two-baryon azimuthal correlations in pp collisions at LHC energies on the QGP
Implication of two-baryon azimuthal correlations in pp collisions at LHC energies on the QGP
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DOI：
10.1016/j.physletb.2022.137063
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发表时间：
2021-12
影响因子：
4.4
通讯作者：
Liuyao Zhang;Jinhui Chen;Wei Li;Zi-Wei Lin
中科院分区：
文献类型：
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作者：
Liuyao Zhang;Jinhui Chen;Wei Li;Zi-Wei Lin
s= 7 TeV 的 pp 碰撞中两个质子或两个反质子方位相关的近侧凹陷已通过实验观察到，然后在我们早期的研究中使用多相输运模型进行了定性再现。在本研究中，我们进一步研究了小型碰撞系统中二重子相关性中凹陷特征的起源。我们发现初始的部分子级空间相关性、部分子级的有限膨胀和夸克聚结是导致近侧凹陷的重要因素。特别是，我们发现部分子系统的有限展开导致强子化时有限的空间动量相关性，然后将坐标空间中的近侧凹陷转换为动量空间中的近侧凹陷。这些结果表明，在 pp 碰撞中形成了具有有限寿命的粒子物质。需要进一步的研究来确定粒子物质是否接近局部平衡并因此可以被称为 QGP 还是远离局部平衡。
The near-side depression in two-proton or two-antiproton azimuthal correlations in pp collisions at s= 7 TeV has been observed experimentally and then qualitatively reproduced in our earlier studies with a multi-phase transport model. In this study, we further investigate the origin of the depression feature in two-baryon correlations in small collision systems. We find that the initial parton-level spatial correlation, a finite expansion in the parton stage, and quark coalescence are important ingredients leading to the near-side depression. In particular, we find that a finite expansion of the parton system leads to a finite space-momentum correlation at hadronization, which then converts the near-side depression in the coordinate space to that in the momentum space. These results suggest that a partonic matter with a finite lifetime is formed in the pp collisions. Further studies are needed to determine whether the partonic matter is near local equilibrium and can thus be called a QGP or far away from local equilibrium.