Investigating the tetraquark structure of the new mesons

Using the QCD sum rule approach we investigate the possible four-quark structure of the recently observed mesons $D_{sJ}^{+}(2317)$, firstly observed by BaBaR, X(3872), firstly observed by BELLE and $D_0^{*0}(2308)$ observed by BELLE. We use diquark-antidiquark currents and work in full QCD, without relying on $1/m_c$ expansion. Our results indicate that a four-quark structure is acceptable for these mesons.