de Soto, FelicianoBlossier, B.Boucaud, P.Morenas, V.Gravina, M.Pène, O.Rodríguez-Quintero, J.2014-06-302014-06-302010-08Physical Review D - Particles, Fields, Gravitation and Cosmology, 82 (3), art. no. 0345101550-7998http://hdl.handle.net/10433/1001We present results concerning the nonperturbative evaluation of the ghost-gluon running QCD coupling constant from Nf=2 twisted-mass lattice calculations. A novel method for calibrating the lattice spacing, independent of the string tension and hadron spectrum, is presented with results in agreement with previous estimates. The value of ^MS¯¯¯¯¯¯ is computed from the running of the QCD coupling only after extrapolating to zero dynamical quark mass and after removing a nonperturbative operator-product expansion contribution that is assumed to be dominated by the dimension-two ¿A2¿ gluon condensate. The effect due to the dynamical quark mass in the determination of ^MS¯¯¯¯¯¯ is discussed.application/pdfenAmerican Physical SocietyGhost-gluon couplingLatticejournal articleopen access