Precision computation of a low-energy reference scale in quenched lattice QCD Original Research Article

We present results for the reference scale r0 in SU(3) Lattice Gauge Theory for β = 6g02 in the range 5.7 ⩽ β ⩽ 6.57. The high relative accuracy of 0.3–0.6% in r0/a was achieved through good statistics, the application of a multi-hit procedure and a variational approach in the computation of Wilson loops. A precise definition of the force used to extract r0 has been used throughout the calculation which guarantees that r0/a is a smooth function of the bare coupling and that subsequent continuum extrapolations are possible. The results are applied to the continuum extrapolations of the energy gap Δ in the static quark potential and the scale Lmax/r0 used in the calculation of the running coupling constant.