New insight into the exotic states strongly coupled with the DD‾^∗ from the T_cc

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 DD¯^∗ interaction by charge conjugation. Our results show that the DD¯^∗ 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 DD¯^∗ and cc¯ components, although the cc¯ 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 X̃(3872) and h_c(2P), respectively. Our combined study provides valuable insights into the nature of these DD^∗/DD¯^∗ exotic states.