Non-perturbative quark mass renormalization in quenched lattice QCD
  The renormalization factor relating the bare to the renormalization group invariant quark masses is accurately calculated in quenched lattice QCD using a recursive finite-size technique. The result is presented in the form of a product of a universal factor times another factor, which depends on the details of the lattice theory but is easy to compute, since it does not involve any large scale differences. As a byproduct the Lambda-parameter of the theory is obtained with a total error of 8%. 
Stefano Capitani, Martin L\"uscher, Rainer Sommer and Hartmut Wittig