Understanding $D_{sJ}(2317)$

We analyze the hadronic and radiative decay modes of the recently observed $D_{sJ}(2317)$ meson, in the hypothesis that it can be identifield with the scalar $s_\ell^P={1\over 2}^+$ state of $c \bar s$ spectrum ($D_{s0}$). The method is based on heavy quark symmetries and Vector Meson Dominance ansatz. We find that the hadronic isospin violating mode $D_{s0} \to D_s \pi^0$ is enhanced with respect to the radiative mode $D_{s0} \to D_s^* \gamma$. The estimated width of the meson is $\Gamma(D_{s0})\simeq 7$ KeV.