High-Precision c and b Masses, and QCD Coupling from Current-Current Correlators in Lattice and Continuum QCD
Abstract
We extend our earlier lattice-QCD analysis of heavy-quark correlators to smaller lattice spacings and larger masses to obtain new values for the c mass and QCD coupling, and, for the first time, values for the b mass: mc(3GeV,nf=4)=0.986(6)GeV, alphamsb(MZ,nf=5)=0.1183(7), and mb(10GeV,nf=5)=3.617(25)GeV. These are among the most accurate determinations by any method. We check our results using a nonperturbative determination of the mass ratio mb(mu,nf)/mc(mu,nf); the two methods agree to within our 1% errors and taken together imply mb/mc=4.51(4). We also update our previous analysis of alphamsb from Wilson loops to account for revised values for r1 and r1/a, finding a new value alpha(MZ,nf=5)=0.1184(6); and we update our recent values for light-quark masses from the ratio mc/ms. Finally, in the Appendix, we derive a procedure for simplifying and accelerating complicated least-squares fits.