2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/105865We present an effective field theory suitable to describe a non-relativistic particle-antiparticle pair of heavy scalars based on the gauge group SU(3). Its formulation is analogous to that of "velocity NRQCD" (vNRQCD), a non-relativistic effective theory for heavy quark pairs. The matching conditions with scalar QCD and the renormalization group evolution of the effective theory are discussed. The non-relativistic framework proposed here suffices to compute scalar-antiscalar bound state energies at next-to-next-to-leading-logarithmic (NNLL) order and next-to-leading-logarithmic (NLL) threshold production of squarks in $e^+e^-$ and $γγ$ collisions, in particular of the lighter scalar top quark at a future Linear Collider.4 pages, 3 figures, uses PoS style. Contribution to the proceedings of the International Europhysics Conference on High Energy Physics (HEP2005), Lisboa, Portugal, 21-27 July 2005High Energy Physics - Phenomenologytext