Non-perturbative renormalisation with interpolating momentum schemes

Abstract

Hadronic matrix elements evaluated on the lattice can be converted to a continuum scheme such as $\text{MSbar}$ using intermediate non-perturbative renormalisation schemes. Discretisation effects on the lattice and convergence of the continuum perturbation theory are both scheme dependent and we explore this dependence in the framework of the Rome-Southampton method for generalised kinematics. In particular, we implement several non-exceptional {\em interpolating} momentum schemes, where the momentum transfer is {\em not} restricted to the symmetric point defined in RI/SMOM. Using flavour non-singlet quark bilinears, we compute the renormalisation factors of the quark mass and wave function for $N_f=3$ flavours of dynamical quarks. We investigate the perturbative and non-perturbative scale-dependencies. Our numerical results are obtained from lattice simulations performed with Domain-Wall fermions, based on ensembles generated by RBC-UKQCD collaborations; we use two different lattice spacings $1/a\sim 1.79$ and $2.38$ GeV. We also give the numerical values for the relevant anomalous dimensions and matching coefficients at next-to-next-to-leading order.