Hadronic decays of the heavy-quark-spin molecular partner of T cc

Starting from the hypothesis that the T thorn ccdiscovered at LHCb is a D ? thorn D0=D ?0D thorn hadronic molecule, we consider the partial width of its heavy quark spin partner, the Tcc ? thorn as a D ? thorn D ?0shallow bound state, decaying into the D ?D pi final states including the contributions of the D ?D and D ?pi final state interaction by using a nonrelativistic effective field theory. Because of the existence of the T thorn ccpole, the I1/40D ?D rescattering can give a sizeable correction up to about 40% to the decay widths considering only the tree diagrams, and the D ?pi rescattering correction is about 10%. The four-body partial widths of the T ? thorn cc into DD pi pi are also explicitly calculated, and we find that the interference effect between different intermediate D ?D pi states is small. The total width of the T ? thorn cc is predicted to be about 41 keV.