2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/215993The pole trajectory of Efimov states for a three-body $ααβ$ system with $αα$ unbound and $αβ$ bound is calculated using a zero-range Dirac-$δ$ potential. It is showed that a three-body bound state turns into a virtual one by increasing the $αβ$ binding energy. This result is consistent with previous results for three equal mass particles. The present approach considers the $n-n-^{18}C$ halo nucleus. However, the results have good perspective to be tested and applied in ultracold atomic systems, where one can realize such three-body configuration with tunable two-body interaction.Proceedings of the 20th European Conference on Few-Body Problems in Physics. To be published in Few-Body SystemsNuclear Theorytext