2019 July 22
2019 September 13
In this second part we continue the overview of the recent lattice determination of αs by the ALPHA collaboration. Starting from the result for ΛNf=3MS/μ0 discussed in the first part , we first present a precise non-perturbative determination of the Λ-parameter ofNf=3 QCD. Using perturbative decoupling to match theNf=3 andNf=5 theories we then extract a precise value for αs. The final result:αs(mZ) =0.11852(84), reaches subpercent accuracy.