Molecular effects in Charmonium Spectrum

Abstract

We study the influence of possible molecular structures in the charmonium spectrum. We focus on the $0^{++}$ and $1^{--}$ sectors. In the first one we coupled the $2 ^3P_0$ $q\bar q$ pair with $DD$, $J/\psi \omega$, $D_sD_s$ and $J/\psi\phi$ channels and we obtain two states compatibles with the X(3945) and the Y(3940). In the second one we include the $3^3S_1$ and $2^3D_1$ charmonium states coupled to $DD$, $DD^*$, $D^*D^*$, $D_sD_s$, $D_sD_s^*$ and $D_s^*D_s^*$. In this calculation we obtain a new molecular state that could be the G(3900) or the controversial Y(4008) and two $c\bar c$ states dressed by the molecular components assigned to the $\psi(4040)$ and the $\psi(4160)$. The two $c\bar c$ states show interesting properties and in particular they solve the strong disagreement of the decay branching ratios measured by BABAR.