Two-Loop Ultrasoft Running of the O(v^2) QCD Quark Potentials
  The two-loop ultrasoft contributions to the next-to-leading logarithmic (NLL) running of the QCD potentials at order v^2 are determined. The results represent an important step towards the next-to-next-to-leading logarithmic (NNLL) description of heavy quark pair production and annihilation close to threshold. 
Andre H. Hoang, Maximilian Stahlhofen