Decoupling of heavy quarks as a tool to determine the strong coupling

The determination of the strong coupling in Lattice QCD requires to connect the low energy regime of the theory with the high energy perturbative regime. In this talk I will show that one can use heavy quarks to connect QCD with the pure gauge theory. This approach allows to perform the bulk of the computation in the simpler setup of the pure gauge theory. Following this approach the ALPHA collaboration has recently produced a precise result for the strong coupling with uncertainties still...