${\Theta }^{+}\mathrm{}\left(1540\right)\mathrm{}$ as a heptaquark with the overlap of a pion, a kaon, and a nucleon

We study the very recently discovered ${\Theta }^{+}\mathrm{}\left(1540\right)\mathrm{}$ at SPring-8, at ITEP and at CLAS-Thomas Jefferson Lab. We apply the same RGM techniques that already explained with success the repulsive hard core of nucleon-nucleon, kaon-nucleon exotic scattering, and the attractive hard core present in pion-nucleon and pion-pion nonexotic scattering. We find that the $K-N$ repulsion excludes the ${\Theta }^{+}$ as a $K-N$ s-wave pentaquark. We explore the ${\Theta }^{+}$ as a heptaquark, equivalent to a $N+\pi +K$ Borromean bound state, with positive parity and total isospin $I=0.\mathrm{}$ We find that the kaon-nucleon repulsion is canceled by the attraction existing both in the pion-nucleon and pion-kaon channels. Although we are not yet able to bind the total three body system, we find that the ${\Theta }^{+}$ may still be a heptaquark state. We conclude with predictions that can be tested experimentally.