Distance between various discretized fermion actions

We present the leading-order mixed-action effect ?(mix)= m(2),r;vs - m(2),r;vv+m(2),r;ss/2 using highly improved staggered quarks (HISQ), clover, or overlap valence fermion actions on gauge ensembles using various sea fermion actions across a widely used lattice spacing range a ? [0.04; 0.19] fm. The results suggest that ?mixdecreases as the fourth order of the lattice spacing on the gauge ensembles with dynamical chiral sea fermions, such as domain wall or HISQ fermions. When a clover sea fermion action that has explicit chiral symmetry breaking is used in the ensemble, ?mix can be much larger regardless of the valence fermion action used.

Automated summary

In this study, we present the leading-order mixed-action effect ?(mix)= m(2),r;vs - m(2),r;vv+m(2),r;ss/2 using highly improved staggered quarks (HISQ), clover, or overlap valence fermion actions on gauge ensembles using various sea fermion actions across a widely used lattice spacing range a ? [0.04; 0.19] fm. The results suggest that ?mix decreases as the fourth order of the lattice spacing on the gauge ensembles with dynamical chiral sea fermions, such as domain wall or HISQ fermions. When a clover sea fermion action that has explicit chiral symmetry breaking is used in the ensemble, ?mix can be much larger regardless of the valence fermion action used.