Long-range structure of T plus cc state

Tcc is a very near-threshold state (below the D*+D0 threshold about 273 keV). Its long-distance structure is of the significance. In the molecular scheme, we relate the coupling constants of Tcc with D*+D0 and D*0D+ to its binding energy and mixing angle of two components with a coupled-channel effective field theory without cutoff-dependence and prior isospin assignment. We investigate the kinetically allowed strong decays Tcc-, D0D0 pi+, Tcc-, D+D0 pi 0 and radiative decays Tcc-,D+D0 gamma and show that the decay width of Tcc-, D0D0 pi+ is the largest one, which is just the experimental observation channel. Our results show that the decay width obtained in the first analysis from LHCb collaboration in Breit-Wigner distribution is over-estimated. Our results were supported by the following experimental analysis from LHCb within unitarized Breit-Wigner formalism.