Experimental observation of dynamical resonances in the H + H₂ reaction

We report observation of dynamical resonances in the reaction H+H₂(v=0,j=0.2){→}H₂(v',j')+H. The reactive cross section as a function of v' and j' is determined under single-collision conditions for 22 total energies between 0.95 and 1.37 eV. Resonances appear as sharp increases in the v'=1 cross section at 0.97, 1.20, and 1.26 eV, and possibly 1.11 eV. These energies are in excellent agreement with the energies of theoretically predicted Feshbach resonances in the reaction.