Strong running coupling at τ and Z(0) mass scales from lattice QCD

Phys Rev Lett. 2012 Jun 29;108(26):262002. doi: 10.1103/PhysRevLett.108.262002. Epub 2012 Jun 26.

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 momentum-subtraction Taylor scheme. We provide readers with estimates of α(MS[over ¯])(m(τ)(2)) and α(MS[over ¯])(m(Z)(2)) in very good agreement with experimental results. Including a dynamical c quark makes the needed running of α(MS[over ¯]) safer.