Ghost-gluon coupling, power corrections, and Λ(MS)over-bar from lattice QCD with a dynamical charm

This paper is a first report on the determination of Lambda((MS) over bar) from lattice simulations with 2 + 1 + 1 twisted-mass dynamical flavors via the computation of the ghost-gluon coupling renormalized in the MOM Taylor scheme. We show this approach allows a very good control of the lattice artefacts and confirm the picture from previous works with quenched and N-f = 2 twisted-mass field configurations, which prove the necessity to include nonperturbative power corrections in the description of the running. We provide an estimate of Lambda((MS) over bar) in very good agreement with experimental results. To our knowledge, it is the first calculation with a dynamical charm quark which makes the running up to alpha(s)(M-Z) much safer.