On a possible tetraquark cousin of the Theta+

Abstract

If a narrow + pentaquark exists, it is likely that a ud¯s–ud triquark-diquark configuration is a significant component of its wave function. If so, the mechanism responsible for the binding of a triquark and a diquark is also likely to bind the triquark to an ¯s antiquark. We discuss the expected properties of such a ud¯s–¯s tetraquark meson. In particular, we point out that for a 0+ isoscalar ud¯s¯s meson the lowest allowed decay mode is a four-body KK channel with a very small phase space and a distinctive experimental signature.