  Both the FINUDA and AMADEUS experiments evidenced a low $\Sigma^+$ momentum
component when investigating $\Sigma^+ \pi^-$ pairs produced in K$^-$ nuclear
capture. This component is interpreted as a consequence of Gamov state
formation, with the hyperon trapped in the Coulomb field of the residual
nucleus. Description of such states and their participation in the capture
reaction is presented. Some consequences are indicated.
