Bound states of $\Theta^+$ in nuclei
  We study the binding energy and the width of the $\Theta^+$ in nuclei, associated to the $K N$ and $ K \pi N$ components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind the $\Theta^+$ in nuclei. Pauli blocking and binding effects on the $K N$ decay reduce considerably the $\Theta^+$ decay width in nuclei and medium effects associated to the $ K \pi N$ component also lead to a very small width, as a consequence of which one finds separation between the bound levels considerably larger than the width of the states. 
E. Oset, D. Cabrera, Q. B. Li, V.K. Magas and M. J. Vicente Vacas