Up-, down-, strange-, charm-, and bottom-quark masses from four-flavor lattice QCD

摘要

We calculate the up-, down-, strange-, charm-, and bottom-quark masses using the MILC highly improved staggered-quark ensembles with four flavors of dynamical quarks. We use ensembles at six lattice spacings ranging from a ≈ 0.15 to 0.03 fm and with both physical and unphysical values of the two light and the strange sea-quark masses. We use a new method based on heavy-quark effective theory (HQET) to extract quark masses from heavy-light pseudoscalar meson masses. Combining our analysis with our separate determination of ratios of light-quark masses we present masses of the up, down, strange, charm, and bottom quarks. Our results for the MS-renormalized masses are m_u(2 GeV) = 2.130(41) MeV, m_d(2 GeV) = 4.675(56) MeV, m_s(2 GeV) = 92.47(69) MeV, m_c(3 GeV) = 983.7(5.6) MeV, and m_c(m_c)=1273(10)MeV, with four active flavors; and m_b(m_b)=4195(14)MeV with five active flavors.We also obtain ratios of quark masses m_c/m_s = 11.783(25), m_b/m_s = 53.94(12), and m_b/m_c = 4.578(8). The result for m_c matches the precision of the most precise calculation to date, and the other masses and all quoted ratios are the most precise to date. Moreover, these results are the first with a perturbative accuracy of α_s~4. As byproducts of our method, we obtain the matrix elements of HQET operators with dimension 4 and 5: Λ_(MRS) = 555(31) MeV in the minimal renormalon-subtracted (MRS) scheme, μ_π~2= 0.05(22) GeV~2, and μ_G~2(m_b) = 0.38(2) GeV~2. The MRS scheme [Phys. Rev. D 97, 034503 (2018)] is the key new aspect of our method.