A doubly charmed strange molecule from coupled-channel dynamics

We investigate a doubly charmed molecular state Tccs̄ with $C=+2$, S=+1, and $I=1/2$ in an off-shell coupled-channel formalism. Constructing the interaction kernel from a meson-exchange model based on an effective Lagrangian and solving the coupled-channel scattering equation in the Blankenbecler-Sugar reduction, we find a pole only for JP=1⁺ among JP=0^±, 1^±, and 2^±. With the reduced cutoff mass of $600$~MeV, we obtain a mass of $3972.90$~MeV, which corresponds to a binding energy of $4.01$~MeV relative to the D^*Dₛ threshold. Examining the relative signs and magnitudes of the S-wave channel couplings extracted from the pole residues, we demonstrate that the pole belongs predominantly to the triplet (3A) representation. We also discuss the relevance of heavy-quark spin symmetry to the bound state.