Dynamics of ${\Omega }^{-}$

A dynamical calculation is performed for the ${\Omega }^{-}$ in the $\Xi \overline{K}\to \Xi \overline{K}$ amplitude, using the $\frac{N}{D}$ method. The forces considered are due to the $\Sigma$ exchange in the crossed channel, as well as the others arising from the far left-hand cut. The latter ones are dealt with in the manner of Balázs. It is seen that the ${\Omega }^{-}$ can be generated self-consistently with a mass equal to about 1540 MeV.