Strong coupling constant and heavy quark masses in 2+1 flavor QCD

Abstract

We present a determination of the strong coupling constant and heavy quark masses in (2+1)-flavor QCD using lattice calculations of the moments of the pseudo-scalar quarkonium correlators at several values of the heavy valence quark mass with Highly Improved Staggered Quark (HISQ) action. We determine the strong coupling constant in the $\overline{MS}$ scheme at four low-energy scales corresponding to $m_c$, $1.5m_c$, $2m_c$, and $3m_c$, with $m_c$ being the charm quark mass. The novel feature of our analysis that up to eleven lattice spacings are used in the continuum extrapolations, with the smallest lattice spacing being $0.025$ fm. We obtain ${\Lambda }_{\overline{MS}}^{n_f=3}=298\pm 16$ MeV, which is equivalent to ${\alpha }_s(\mu =M_Z,n_f=5)=0.1159(12)$. For the charm and bottom quark masses in the $\overline{MS}$ scheme, we obtain: $m_c(\mu =m_c,n_f=4)=1.265(10)$ GeV and $m_b(\mu =m_b,n_f=5)=4.188(37)$ GeV.

Comments: 32 pages, 10 figures, 18 Tables