论文标题
探测强核相互作用的核心
Probing the core of the strong nuclear interaction
论文作者
论文摘要
核子（质子和中子）之间的强核相互作用是将原子核固定在一起的有效力。这种力源于夸克与胶子之间的基本相互作用（核子的组成），这些相互作用是由量子染色体动力学方程（QCD）描述的。但是，由于无法直接解决这些方程式，物理学家使用有效模型来描述核相互作用，这些模型在典型的核间距离上受到良好的约束，但距离较短。这限制了我们描述高密度核物质的能力，例如中子恒星的核心。在这里，我们使用高能电子散射测量测量值，以短距离，高弹药构型分离核子对，从而访问了实验以前未通过实验探索的运动学状态，对应于400 MEV/c以上的相对动量。随着两个核子之间的相对动量增加，其分离也会减少，我们观察到从旋转依赖性张量强度向主要是自旋依赖性标量强度的过渡。这些结果表明，使用此类测量值在短距离下研究核相互作用，并支持使用具有两体和三体有效相互作用的点状核子来描述核系统的密度，高于原子核的中央密度几倍。
The strong nuclear interaction between nucleons (protons and neutrons) is the effective force that holds the atomic nucleus together. This force stems from fundamental interactions between quarks and gluons (the constituents of nucleons) that are described by the equations of Quantum Chromodynamics (QCD). However, as these equations cannot be solved directly, physicists resort to describing nuclear interactions using effective models that are well constrained at typical inter-nucleon distances in nuclei but not at shorter distances. This limits our ability to describe high-density nuclear matter such as in the cores of neutron stars. Here we use high-energy electron scattering measurements that isolate nucleon pairs in short-distance, high-momentum configurations thereby accessing a kinematical regime that has not been previously explored by experiments, corresponding to relative momenta above 400 MeV/c. As the relative momentum between two nucleons increases and their separation thereby decreases, we observe a transition from a spin-dependent tensor-force to a predominantly spin-independent scalar-force. These results demonstrate the power of using such measurements to study the nuclear interaction at short-distances and also support the use of point-like nucleons with two- and three-body effective interactions to describe nuclear systems up to densities several times higher than the central density of atomic nuclei.
