Renormalisation constants of quark bilinears in lattice QCD with four dynamical Wilson quarks

We present preliminary results of the non-perturbative computation of the RI-MOM renormalisation constants in a mass-independent scheme for the action with Iwasaki glue and four dynamical Wilson quarks employed by ETMC. Our project requires dedicated gauge ensembles with four degenerate sea quark flavours at three lattice spacings and at several values of the standard and twisted quark mass parameters. The RI-MOM renormalisation constants are obtained from appropriate O(a) improved estimators extrapolated to the chiral limit.