2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/201179We discuss strategies to determine hadronic decay couplings from lattice studies. As an application, we explore the decay of a vector meson to two pseudoscalar mesons with $N_f=2$ flavours of sea quark. Although we are working with quark masses that do not allow a physical decay, we show how the transition rate can be evaluated from the amplitude for $ρ\to ππ$ and from the annihilation component of $ππ\to ππ$. We explore the decay amplitude for two different pion momenta and find consistent results. The coupling strength we find is in agreement with experiment. We also find evidence for a shift in the $ρ$ mass caused by mixing with two pion states.Proc. Latt03 (spectrum), 3 pages, 4 figsHigh Energy Physics - Latticetext