New insight into the exotic states strongly coupled with the [formula omitted] from the [formula omitted].

We have investigated the internal structure of the open- and hidden-charmed ( DD ∗ / D ¯ D ∗ ) molecules in the unified framework. We first fit the experimental lineshape of the T cc + state and extract the DD ∗ interaction, from which the T cc + is assumed to arise solely. Then we obtain the D D ¯ ∗ interaction by charge conjugation. Our results show that the D D ¯ ∗ interaction is attractive but insufficient to form X (3872) as a bound state. Instead, its formation requires the crucial involvement of the coupled channel effect between the D D ¯ ∗ and c c ¯ components, although the c c ¯ accounts for approximately 1 % only. Besides X (3872) , we have obtained a higher-energy state around 3957.9 MeV with a width of 16.7 MeV, which may be a potential candidate for the X (3940). In J PC = 1 + - sector, we have found two states related to the iso-scalar X ̃ (3872) and h c (2 P) , respectively. Our combined study provides valuable insights into the nature of these DD ∗ / D D ¯ ∗ exotic states. [ABSTRACT FROM AUTHOR]