Determination Of (M)Over-Bar(B)/(M)Over-Bar(C) And (M)Over-Bar(B) From N(F)=4 Lattice Qcd Plus Qed

We extend HPQCD's earlier n(f) = 2 + 1 + 1 lattice-QCD analysis of the ratio of (MS) over bar masses of the b and c quark to include results from finer lattices (down to 0.03 fm) and a new calculation of QED contributions to the mass ratio. We find that (m) over bar (b)(mu)/(m) over bar (c)(mu) = 4.586(12) at renormalization scale mu = 3 GeV. This result is nonperturbative. Combining it with HPQCD's recent lattice QCD + QED determination of (m) over bar (c)(3 GeV) gives a new value for the b-quark mass: (m) over bar (b)(3 GeV) = 4.513(26) GeV. The b-mass corresponds to (m) over bar (b)(mu)((m) over bar (b), n(f) = 5) = 4.202(21) GeV. These results are the first based on simulations that include QED.