Neutron emission in ultraperipheral Pb-Pb collisions at s N N = 5.02 TeV
Neutron emission in ultraperipheral Pb-Pb collisions at s N N = 5.02 TeV
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s N N = 5.02 TeV 超外周 Pb-Pb 碰撞中的中子发射
DOI：
10.1103/physrevc.107.064902
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发表时间：
2023
影响因子：
3.1
通讯作者：
Acharya S
中科院分区：
文献类型：
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作者：
Acharya S
在没有核密度重叠的相对论核的超外围碰撞（UPC）中，两个核被其碰撞伙伴的洛伦兹收缩库仑场激发。在这些UPC中，典型的核激发能量低于几十MeV，并且在初级核的电磁解离（EMD）中发射少量核子，这与强子相互作用中的完全核碎裂形成鲜明对比。 TeV 原子核 UPC 中给定数量中子的发射截面是用大型强子对撞机 ALICE 探测器的中子零度量热计 (ZDC) 测量的，采用了与之前在 TeV 进行的研究中使用的类似技术。此外，首次测量了 EMD 中仅发射一个、两个、三个、四个和五个前向中子的横截面，不伴随前向质子的发射，因此大多分别对应于 的产生。可用模型的预测很好地描述了测量的横截面。这些横截面可用于评估次级核对大型强子对撞机组件的影响，特别是对超导磁体的影响，并且还为未来圆形对撞机（FCC-hh）的设计提供有用的输入。
In ultraperipheral collisions (UPCs) of relativistic nuclei without overlap of nuclear densities, the two nuclei are excited by the Lorentz-contracted Coulomb fields of their collision partners. In these UPCs, the typical nuclear excitation energy is below a few tens of MeV, and a small number of nucleons are emitted in electromagnetic dissociation (EMD) of primary nuclei, in contrast to complete nuclear fragmentation in hadronic interactions. The cross sections of emission of given numbers of neutrons in UPCs ofnuclei atTeV were measured with the neutron zero degree calorimeters (ZDCs) of the ALICE detector at the LHC, exploiting a similar technique to that used in previous studies performed atTeV. In addition, the cross sections for the exclusive emission of one, two, three, four, and five forward neutrons in the EMD, not accompanied by the emission of forward protons, and thus mostly corresponding to the production of, respectively, were measured for the first time. The predictions from the available models describe the measured cross sections well. These cross sections can be used for evaluating the impact of secondary nuclei on the LHC components, in particular, on superconducting magnets, and also provide useful input for the design of the Future Circular Collider (FCC-hh).