Ghost-gluon coupling, power corrections and ${\Lambda }_{\overline{MS}}$ from twisted-mass lattice QCD at $N_f=2$

Abstract

A non-perturbative calculation of the ghost-gluon running QCD coupling constant is performed using $N_f=2$ twisted-mass dynamical fermions. The extraction of ${\Lambda }_{\overline{MS}}$ in the chiral limit reveals the presence of a non-perturbative OPE contribution that is assumed to be dominated by a dimension-two $\text{VEV}{A}^2$ condensate. In this contest a novel method for calibrating the lattice spacing in lattice simulations is presented.

Comments: 7 pages, 4 figures, XXVIII International Symposium on Lattice Field Theory 2010