Charmonium potentials: Matching perturbative and lattice QCD

Understand

Central and spin-spin potentials for charmonium, constructed from Nambu-Bethe-Salpeter amplitudes in lattice simulations of full QCD, are matched with results from perturbative QCD at an appropriate distance scale.

• This matching is made possible by defining the perturbative potentials through Fourier transforms with a low-momentum cutoff.
• The central (spin-independent) potential is compared with potentials derived from an expansion in powers of the inverse quark mass.
• A well-controlled continuation of the charmonium spin-spin potential from lattice QCD to short distances is performed.