Vibrational wave function of a radiatively dissociating level of ${\mathrm{H}}_2$${\mathrm{}}^{/\mathrm{e}\mathrm{m}\mathrm{p}\mathrm{h}>\mathrm{}}$ obtained from the kinetic–energy distribution of the H fragments

Using translational spectroscopy, we have measured the released kinetic energies of the H fragments that are produced in the radiative decay of the g ${\mathrm{}}^3$ ${\mathrm{\Sigma }}_{\mathrm{g}}$(v=5,N=1) level to the repulsive b ${\mathrm{}}^3$ ${\mathrm{\Sigma }}_{\mathrm{u}}$ state. The energy distribution shows undulations directly related to the structure of the excited-state vibrational wave function. For the first time a distribution over the internuclear distance, which involves the excited-state wave function and the transition dipole moment, has been obtained by a transformation of the measured spectrum. We find differences with a calculated distribution for which we give a possible explanation.