$D D^{*}$ potentials in chiral perturbation theory and possible molecular states

The $DD^{*}$ potentials are studied within the framework of heavy meson chiral effective field theory. We have obtained the effective potentials of the $DD^{*}$ system up to $O(epsilon^2)$ at one loop level. In addition to the one-pion exchange contribution, the contact and two-pion exchange interactions are also investigated in detail. Furthermore, we have searched for the possible molecular states by solving Schrodinger equation with the potentials. We notice that the contact and two-pion exchange potentials are non-negligible numerically and important for the existence of a bound state. In our results, no bound state is founded in the $I=0$ channel within a wide range of cutoff parameter, while there exists a bound state in the $I=1$ channel as cutoff is near $m_rho$ in our approach.