6 research outputs found
The Theta+ (1540) as a heptaquark with the overlap of a pion, a kaon and a nucleon
We study the very recently discovered Theta+ (1540) 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 non-exotic 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. We find that the kaon-nucleon repulsion is cancelled 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.Comment: 5 pages, 5 figures, 2 tables, submitted to Phys. Rev. D, rapid
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