QCD Inequalities and the $D_s(2320)$

Abstract

We discuss the new state $D_{sJ}(2317)$ discovered by BaBar and demonstrate using QCD inequalities that if indeed the $f_0(980)$ and the new $D_{sJ}(2317)$ ($0^{+}$) are primarilly made of four quarks that a new I=0 ``$\bar{D}D$ bound state'' at a mass smaller than 3660 MeV must exist. Observation of such a state will constitute definitive evidence for four-quark states.