Triquark structure and isospin symmetry breaking in exotic Ds mesons

The color antitriplet triquark q (q) over bar (q) over bar is considered as a compact component in the tetraquark structure cq (q) over bar (q) over bar of exotic D-s mesons. We discuss the mass spectrum and the flavor mixing of the triquarks by using the instanton induced interaction and the one-gluon exchange potentials. As a characteristic property of the triquark, we investigate the isospin violation. It is shown that the flavor (3) over bar (isosinglet) and 6 (isotriplet) states may be strongly mixed and then are identified with D-s(2632).