The strong running coupling at $\tau$ and $Z_0$ mass scales from lattice QCD

Authors :: Blossier, B.
Boucaud, Ph.
Brinet, M.
De Soto, F.
Du, X.
Morenas, V.
Pène, O.
Petrov, K.
Rodríguez-Quintero, J.
Publication Year :: 2012
Abstract: This letter reports on the first computation, from data obtained in lattice QCD with $u,d,s$ and $c$ quarks in the sea, of the running strong coupling via the ghost-gluon coupling renormalized in the MOM Taylor scheme. We provide with estimates of $\ams(m_\tau^2)$ and $\ams(m_Z^2)$ in very good agreement with experimental results. Including a dynamical c quark makes safer the needed running of $\ams$.<br />Comment: 5 pages, 4 figures, 1 table (references updated)