Interaction of the $\Theta^+$ with the nuclear medium
  We study the selfenergy of the $\Theta^+$ pentaquark in nuclei associated with two types of interaction: the KN decay of the $\Theta^+$ and two meson baryon decay channels of the $\Theta^+$. Whereas the potential related to the first source is quite weak, the second kind of interaction produces a large and attractive potential that could lead to the existence of $\Theta^+$ nuclear bound states. 
M. J. Vicente Vacas, D. Cabrera, Q. B. Li, V. K. Magas and E. Oset