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Gluon and ghost propagators data, obtained in Landau gauge from lattice simulations with two light and two heavy dynamical quark flavours ($N_f$=2+1+1), are described here with a running formula including a four-loop perturbative expression and a nonperturbative OPE correction dominated by the local operator $A^2$. The Wilson coefficients and their variation as a function of the coupling constant are extracted from the numerical data and compared with the theoretical expressions that, after being properly renormalized, are known at ${cal O}(alpha^4)$. As also $Lambda_{msbar}$ is rather well known for $N_f$=2+1+1, this allows for a precise consistency test of the OPE approach in the joint description of different observables.
We present simulation details and results for the light hadron spectrum in N f = 2 + 1 lattice QCD with the nonperturbatively O(a)-improved Wilson quark action and the Iwasaki gauge action. Simulations are carried out at a lattice spacing of 0.09 fm
We determine the strong coupling constant $alpha_s$ from the static QCD potential by matching a theoretical calculation with a lattice QCD computation. We employ a new theoretical formulation based on the operator product expansion, in which renormal
We present a lattice calculation of the renormalized running coupling constant in symmetric (MOM) and asymmetric ($widetilde{rm MOM}$) momentum substraction schemes including $u$, $d$, $s$ and $c$ quarks in the sea. An Operator Product Expansion domi
As computing resources are limited, choosing the parameters for a full Lattice QCD simulation always amounts to a compromise between the competing objectives of a lattice spacing as small, quarks as light, and a volume as large as possible. Aiming to
Lattice calculations of the form factors for the charm semileptonic decays D to K l nu and D to pi l nu provide inputs to direct determinations of the CKM matrix elements |V(cs)| and |V(cd)| and can be designed to validate calculations of the form fa