2026/07/27 by Qi-Wei Yuan, Jia-Ting Zhang, Ming-Zhu Liu
#hep-ph
The nature of the scalar charmed meson D0^*(2300) remains one of the most intriguing states in hadron spectroscopy. A prominent interpretation is a two-pole structure generated by the coupled channels Dπ, Dη, Ds K, and Dη', in which the lower pole couples mainly to Dπ and the higher pole to Ds K. Following this picture, we calculate the decay constants of these two poles using the effective Lagrangian approach. The resulting values, fD0^*(lower)=64.6+0.9-1.0 MeV and fD0^*(higher)=80.8+9.6-5.3 MeV, are substantially smaller than those predicted by conventional c q excited-state scenarios. This difference suggests that decay constants can serve as a sensitive probe to discriminate between different internal structures of the D0^*(2300). As a phenomenological application, we further predict the branching fractions for the Cabibbo-favored decays Bs → Ds D0^*, Λb → Λc D0^*, and Ξb → Ξc D0^* within the factorization approach. These predictions provide crucial tests to validate the two-pole interpretation of the D0^*(2300).