标题： 核子σ项的格点QCD变分分析 显示英文标题

标题： Nucleon sigma terms with a variational analysis from Lattice QCD

摘要： 我们从格点QCD中确定核子-σ项。 我们发现，使用标量流的核子三点函数中的主要激发态污染是由于核子与一个核子和标量（σ）介子的S波散射态之间的跃迁引起的。 在这一概念验证研究中，我们分析了一个单个的$N_f=3$系列，其不现实的大π介子质量为$M_\pi=429$ MeV。 当在广义特征向量分析中使用核子-σ类型的插值算符时，激发态污染相比标准方法显著减少。 显示英文摘要

摘要： We determine the nucleon-sigma terms from lattice QCD. We find that the dominant excited state contamination in the nucleon three-point function with a scalar current is due to the transition between the nucleon and a S-wave scattering state of a nucleon and a scalar (sigma) meson. In this proof-of-concept study, we analyse a single $N_f=3$ ensemble with the unphysically large pion mass $M_\pi=429$ MeV. Excited state contamination is substantially reduced compared to the standard method when employing nucleon-sigma type interpolating operators within a generalised eigenvector analysis.