Optically assisted H + H₂ exchange reaction and reactive scattering resonances

Laser catalysis of the collinear H + H₂ exchange reaction is computed with an exact quantum mechanical method. The radiative process is treated with a partitioning theory developed previously, and the scattering calculations are performed using a coupled channels expansion in the artificial channel method. By studying the optical line shape as a function of the scattering energy, the signature of the scattering resonances on the optically induced reaction is unraveled. We show that when the collision energy is tuned to a resonance, laser catalysis results in selective vibrational excitation of the product H₂ molecule. Implications of this effect for past and future experiments are discussed.