标题： $η$和$η'$介子的混合分析 显示英文标题

标题： A Mixed Action Analysis of $η$ and $η'$ Mesons

摘要： 我们研究了$\eta$和$\eta'$粒子及其混合角度，在一种混合作用方法中使用所谓的 Osterwalder-Seiler 阈值夸克，在Wilson扭曲质量海中。这些规范构型由ETMC为$N_f=2+1+1$动力学夸克味和三个晶格间距值生成。主要结果是混合作用与幺正方法之间的差异在接近连续极限时以预期的速率消失$\mathcal{O}(a^2)$。然而，晶格伪迹的个体大小强烈依赖于用于匹配幺正和阈值作用的可观测量。此外，我们展示了对于$\eta$质量，阈值质量和阈值加海夸克质量依赖性显著不同。因此，在这种情况下，仅仅在阈值区域重新调整模拟参数不足以补偿原始夸克质量的不匹配。 显示英文摘要

摘要： We study $\eta$ and $\eta'$ mesons and their mixing angle in a mixed action approach with so-called Osterwalder-Seiler valence quarks on a Wilson twisted mass sea. The gauge configurations have been generated by ETMC for $N_f=2+1+1$ dynamical quark flavours and for three values of the lattice spacing. The main results are that differences in between the mixed action and the unitary approach vanish towards the continuum limit with the expected rate of $\mathcal{O}(a^2)$. The individual size of the lattice artifacts depends, however, strongly on the observable used to match unitary and valence actions. Moreover, we show that for the $\eta$ mass valence and valence plus sea quark mass dependence differ significantly. Hence, in this case a re-tuning of the simulation parameters in the valence sector only is not sufficient to compensate for mismatches in the original quark masses.