Bilinear quark operators in the RI/SMOM scheme at three loops

We consider the renormalization of the matrix elements of the bilinear quark operators $bar{psi}psi$, $bar{psi}gamma_mupsi$, and $bar{psi}sigma_{mu u}psi$ at next-to-next-to-next-to-leading order in QCD perturbation theory at the symmetric subtraction point. This allows us to obtain conversion factors between the $overline{rm MS}$ scheme and the regularization invariant symmetric momentum subtraction (RI/SMOM) scheme. The obtained results can be used to reduce the errors in determinations of quark masses from lattice QCD simulations. The results are given in Landau gauge.