PERTURBATION OF AN EMBEDDED EIGENVALUE BY A NEARBY RESONANCE

Quantum-mechanical systems (including molecules), whose Hamiltonians a dmit the separation (in particular, by the Faddeev method) of a weakly coupled channel, are considered. The width (i,e,, the imaginary part) of the resonance generated by a discrete spectrum eigenvalue of the s eparated channel is studied in the case where the main component of th e Hamiltonian gives rise to another resonance. It is shown that if the real parts of these resonances coincide and these two channels are we akly correlated, then the width of the resonance corresponding to the separated (molecular) channel is inversely proportional to the width o f the main (nuclear) channel resonance. This phenomenon, which is a ki nd of universal law, may play an important role in increasing the nucl ear fusion probability in molecules whose nuclear constituents have na rrow pre-threshold resonances.