Instanton induced quark dynamics and the pentaquark

We analyze the existence of the exotic Θ+ from the perspective of instanton induced quark dynamics. The 't Hooft interaction gives strong attraction in specific channels of the triquark uds¯ and diquark ud configurations. In particular it leads to a light uds¯ triquark cluster, with the mass around 750MeV, in the I=0, S=1/2 and color 3 configuration, and a light ud-diquark configuration, with mass 440MeV, in the I=0, S=0 and color {3¯} configuration. If we consider the pentaquark as a bound state of such triquark and diquark configurations in a relative L=1 state we obtain good agreement with the data. The small width of Θ+ has a natural explanation in this model