Nature. 2020 Dec;588(7837):232-238. doi: 10.1038/s41586-020-3001-6. Epub 2020 Dec 9.
One of the key challenges for nuclear physics today is to understand from first principles the effective interaction between hadrons with different quark content. First successes have been achieved using techniques that solve the dynamics of quarks and gluons on discrete space-time lattices. Experimentally, the dynamics of the strong interaction have been studied by scattering hadrons off each other. Such scattering experiments are difficult or impossible for unstable hadrons and so high-quality measurements exist only for hadrons containing up and down quarks. Here we demonstrate that measuring correlations in the momentum space between hadron pairs produced in ultrarelativistic proton-proton collisions at the CERN Large Hadron Collider (LHC) provides a precise method with which to obtain the missing information on the interaction dynamics between any pair of unstable hadrons. Specifically, we discuss the case of the interaction of baryons containing strange quarks (hyperons). We demonstrate how, using precision measurements of proton-omega baryon correlations, the effect of the strong interaction for this hadron-hadron pair can be studied with precision similar to, and compared with, predictions from lattice calculations. The large number of hyperons identified in proton-proton collisions at the LHC, together with accurate modelling of the small (approximately one femtometre) inter-particle distance and exact predictions for the correlation functions, enables a detailed determination of the short-range part of the nucleon-hyperon interaction.
当今核物理学面临的主要挑战之一是从第一性原理理解具有不同夸克内容的强子之间的有效相互作用。使用解决夸克和胶子在离散时空格子上动力学的技术已经取得了初步成功。在实验上,强相互作用的动力学是通过强子之间的散射来研究的。对于不稳定的强子,这种散射实验是困难的或不可能的,因此只有含有上夸克和下夸克的强子的高质量测量存在。在这里,我们证明了在 CERN 大型强子对撞机(LHC)中进行的相对论质子-质子碰撞中产生的强子对之间在动量空间中的关联的测量提供了一种精确的方法,可以获得任何两个不稳定强子之间相互作用动力学的缺失信息。具体来说,我们讨论了含有奇异夸克的重子(超子)相互作用的情况。我们展示了如何使用质子-ω重子关联的精确测量,以类似于格点计算预测的精度来研究这种强子-强子对的强相互作用。在 LHC 进行的质子-质子碰撞中识别出大量的超子,以及对小(约一飞米)粒子间距离的精确建模和关联函数的精确预测,使得可以详细确定核子-超子相互作用的短程部分。