The $\Delta_{mix}$ parameter in the overlap on domain-wall mixed action

Understand

A direct calculation of the mixed-action parameter $\Delta_{mix}$ with valence overlap fermions on a domain-wall fermion sea is presented.

• The calculation is performed on four ensembles of the 2+1-flavor domain-wall gauge configurations: $24^3 \times 64$ ($a m_l= 0.005$, $a=0.114\fm$) and $32^3 \times 64$ ($a m_l = 0.004, 0.006, 0.008$, $a=0.085\fm$).
• For pion masses close to $300\MeV$ we find \hbox{$\Delta_{mix}=0.030(6)\GeV^4$} at $a=0.114\fm$ and $\Delta_{mix}=0.033(12)\GeV^4$ at $a=0.085\fm$.
• The results are quite independent of the lattice spacing and they are significantly smaller than the results for valence domain-wall fermions on Asqtad sea or those of valence overlap fermions on clover sea.