QCD Static Energy Research Articles

Strong coupling from the QCD static energy

We review the determination of [Formula: see text] that follows from comparing at short distances the QCD static energy at three loops and resummation of the next-to-next-to leading logarithms with its determination in 2+1-flavor lattice QCD provided by the HotQCD collaboration. The result that we obtain is [Formula: see text](1.5 GeV) = 0.336[Formula: see text], corresponding to [Formula: see text](MZ) = 0.1166[Formula: see text]. We outline future possible developments.

A low-energy determination ofαsat three loops

We review one of the most accurate low-energy determinations of $\alpha_s$. Comparing at short distances the QCD static energy at three loops and resummation of the next-to-next-to leading logarithms with its determination in 2+1-flavor lattice QCD, we obtain $\alpha_s(1.5~{\rm GeV})=0.336^{+0.012}_{-0.008}$, which corresponds to $\alpha_s(M_Z)=0.1166^{+0.0012}_{-0.0008}$. We discuss future perspectives.

Precision Determination ofr0ΛMS¯from the QCD Static Energy

We use the recently obtained theoretical expression for the complete QCD static energy at next-to-next-to-next-to leading-logarithmic accuracy to determine r₀ΛMS by comparison with available lattice data, where r₀ is the lattice scale and ΛMS is the QCD scale. We obtain r₀ΛMS=0.637(+0.032)(-0.030) [corrected] for the zero-flavor case. The procedure we describe can be directly used to obtain r₀ΛMS in the unquenched case, when unquenched lattice data for the static energy at short distances becomes available. Using the value of the strong coupling α(s) as an input, the unquenched result would provide a determination of the lattice scale r₀.

QCD static energy at next-to-next-to-next-to leading-logarithmic accuracy

We compute the static energy of QCD at short distances at next-to-next-to-next-to-leading logarithmic accuracy in terms of the three-loop singlet potential. By comparing our results with lattice data we extract the value of the unknown piece of the three-loop singlet potential.

The logarithmic contribution to the QCD static energy at N4LO

Using pNRQCD and known results for the field strength correlator, we calculate the ultrasoft contribution to the QCD static energy of a quark-antiquark pair at short distances at NNNNLO in alpha_s. At the same order, this provides the logarithmic terms of the singlet static potential in pNRQCD and the log alpha_s terms of the static energy.