Diresonance in production and scattering of heavy mesons

We consider the production and scattering amplitudes of heavy mesons in a situation, where there are two closely spaced narrow resonances, whose structure we refer to as a diresonance. Assuming strong overlapping of the resonances coupled to common channels, it is found, using the unitarity and analyticity constraints, that the production amplitudes by a weak source should have similar behavior with energy in different channels. In particular, the ratio of the coefficients for each pole contribution to the production amplitude is fixed at -1.