Observation of perturbations in the probabilities of the GK (1)Sigma(+)(g)-> B (1)Sigma(+)(u) spontaneous transitions of the H-2 molecule: Rotational branching ratios

The line strength ratios for the R and P branches (the rotational branching ratios) are measured for the first time for the GK(1)Sigma(g)(+), v', J' - -> B (1)Sigma(u)(+), v ", J " spontaneous transitions of the H-2 molecule. Values of 73 branching ratios for 18 different (v'-v ") bands with the rota tional quantum numbers J' = 1-9 and vibrational quantum numbers v' = 0-3 an d v " = 0-7 are obtained. Significant discrepancies (exceeding a factor of 20-30) are found between the experimental data and the results of calculati on in the adiabatic approximation using the Honl-London factors and taking into account the effect of vibrational-rotational interaction in the vibrat ional wave functions of combining states. These perturbations are more sign ificant than those observed in our previous work for transitions from level s of both the triplet 3p complex of terms and the singlet and triplet 3d co mplexes of terms of the hydrogen molecule. II was established that the effe cts of perturbation in the rotational branching ratios strongly depend not only on values of J' for separate vibronic bands, but also on values of v' and v " for fixed values of J'.