1BAZAVOV 2018 determine the quark masses using a lattice computation with staggered fermions and four active quark flavors for the ${\mathit {\mathit u}}$, ${\mathit {\mathit d}}$, ${\mathit {\mathit s}}$, ${\mathit {\mathit c}}$ quarks and five active flavors for the ${\mathit {\mathit b}}$ quark.
2CHAKRABORTY 2015 determine ${\mathit m}_{{{\mathit b}}}/{\mathit m}_{{{\mathit s}}}$ from lattice QCD using the HISQ action and including ${{\mathit n}_{{{f}}}}$ = 2+1+1 flavors of sea quarks.
References:
BAZAVOV
2018
PR D98 054517
Up-, down-, strange-, charm-, and bottom-quark masses from four-flavor lattice QCD
CHAKRABORTY
2015
PR D91 054508
High-Precision Quark Masses and QCD Coupling from ${{\mathit n}_{{{f}}}}$ = 4 Lattice QCD