  We report the direct detection of two metastable H(2S) atoms coming from the
dissociation of a single cold H_2 molecule, in coincidence measurements. The
molecular dissociation was induced by electron impact in order to avoid
limitations by the selection rules governing radiative transitions. Two
detectors, placed close from the collision center, measure the neutral
metastable H(2S) through a localized quenching process, which mixes the H(2S)
state with the H(2P), leading to a Lyman-\alpha detection. Our data show the
accomplishment of a coincidence measurement which proves for the first time the
existence of the H(2S)-H(2S) dissociation channel.
