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在p-Pb和Pb-Pb碰撞中,高横动量粒子的相似集体性的证据
V Chekhovsky1, A Hayrapetyan1, V Makarenko1
1Yerevan Physics Institute, Yerevan, Armenia.
Physical review letters
|September 10, 2025
概括
高能粒子碰撞在质子-和-系统中表现出类似的集体行为. 这表明,在高横运动量粒子中,多粒子集体的共同起源.
科学领域:
- 高能物理 高能物理
- 核物理 核物理 核物理
- 量子色态动力学 量子色态动力学
背景情况:
- 带电的哈德龙圆形异构 (v2) 探测重离子碰撞中产生的物质的集体膨胀.
- 了解像质子- (pPb) 碰撞这样的小系统中的集体性的起源,对于解释较大的- (PbPb) 系统的结果至关重要.
研究的目的:
- 在一个广泛的横向运动量 (pT) 范围内,对带电的哈德龙圆形异位 (v2) 的测量进行呈现.
- 在高能量的质子- (pPb) 和- (PbPb) 碰撞中比较v2.
- 调查负责多粒子集体性的潜在机制.
主要方法:
- 通过大型强子对撞机的CMS实验收集的数据.
- 在8.16 TeV的质子- (pPb) 碰撞和在5.02 TeV的- (PbPb) 碰撞的分析.
- 利用四颗粒子累积分析与伪速度分离的子事件来最大限度地减少非集体效应.
主要成果:
- 在高横动量 (pT > 8 GeV) 的带电哈德龙中观察到显著的正形异位 (v2).
- 测量到的v2值被发现在pPb和PbPb碰撞之间具有相似的带电粒子倍数时相似.
- 这些相似之处在广泛的横向动量范围内仍然存在.
结论:
- 在高pT时观察到的v2的相似性表明,在pPb和PbPb系统中,多粒子集体的共同起源.
- 这一发现挑战了一些理论模型,并指出了推动集体性的更普遍的机制.
- 需要进一步的研究来充分阐明初始状态几何和最终状态相互作用的作用.
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