Triquark structure and isospin symmetry breaking in exotic Ds mesons

Abstract

The color anti-triplet triquark $q\bar{q}\bar{q}$ is considered as a compact component in the tetraquark structure $cq\bar{q}\bar{q}$ 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 $\bar{3}$ (isosinglet) and $6$ (isotriplet) states may be strongly mixed and then are identified with $D_s(2632)$.