Deuterons are atomic nuclei composed of a neutron and a proton held together by the strong interaction. Unbound ensembles composed of a deuteron and a third nucleon have been investigated in the past using scattering experiments, and they constitute a fundamental reference in nuclear physics to constrain nuclear interactions and the properties of nuclei. In this work, 𝐾+−𝑑 and 𝑝−𝑑 femtoscopic correlations measured by the ALICE Collaboration in proton-proton (𝑝⁢𝑝) collisions at √𝑠=13  TeV at the Large Hadron Collider (LHC) are presented. It is demonstrated that correlations in momentum space between deuterons and kaons or protons allow us to study three-hadron systems at distances comparable with the proton radius. The analysis of the 𝐾+−𝑑 correlation shows that the relative distances at which deuterons and protons or kaons are produced are around 2 fm. The analysis of the 𝑝−𝑑 correlation shows that only a full three-body calculation that accounts for the internal structure of the deuteron can explain the data. In particular, the sensitivity of the observable to the short-range part of the interaction is demonstrated. These results indicate that correlations involving light nuclei in 𝑝⁢𝑝 collisions at the LHC will also provide access to any three-body system in the strange and charm sectors.

中文翻译：

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探索 LHC 中三体系统的强相互作用


氘子是由中子和质子组成的原子核，通过强相互作用结合在一起。过去已经使用散射实验研究了由一个氘子和第三个核子组成的无束缚系集成，它们构成了核物理学中限制核相互作用和原子核特性的基本参考。在这项工作中，ALICE 合作在大型强子对撞机 （LHC） 中以 √s=13 TeV 的质子-质子 （pp） 碰撞测量了 K+−d 和 p-d 飞秒相关性。结果表明，氘子和 kaons 或质子之间的动量空间相关性使我们能够在与质子半径相当的距离上研究三强子系统。对 K+−d 相关性的分析表明，产生氘子和质子或 kaons 的相对距离约为 2 fm。对 p-d 相关性的分析表明，只有解释氘子内部结构的完整三体计算才能解释这些数据。特别是，证明了 observable 对交互的短程部分的敏感性。这些结果表明，在 LHC 的 pp 碰撞中涉及轻原子核的相关性也将提供对奇异和魅力区中任何三体系统的访问。