High precision determination of $w_0$
In order to perform high precision calculations in lattice QCD for observables of physical interest, especially for dimensionful quantities, it is important to be able to determine the lattice spacing with high accuracy. One choice for scale setting is the observable $w_0$ based on the Wilson flow. It is relatively easy to measure on individual ensembles with high precision. However the value of $w_0$ is not determined by experiment and therefore the value of $w_0$ in physical units has to be be computed on the lattice with high precision before it can be used to set the scale in subsequent calculations. Here we present an lattice calculation aiming to determine $w_0$ with high precision. The calculation is based on a set of configurations featuring a stout smeared staggered fermion action and a Symmanzik improved gauge action.