Physical Review Letters

p. 1-5 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-04-15T14:23:08Z No. of bitstreams: 1 PhysRevLett.111.183203.pdf: 699711 bytes, checksum: 0da26fa2f8dabf69d8021b58f70a09ec (MD5) Approved for entry into archive by Rodrigo Meirelles (rodrigomei@ufba.br) on 2014-09-09T14:22:41Z (GMT) No. of bitstreams: 1 PhysRevLett.111.183203.pdf: 699711 bytes, checksum: 0da26fa2f8dabf69d8021b58f70a09ec (MD5) Made available in DSpace on 2014-09-09T14:22:41Z (GMT). No. of bitstreams: 1 PhysRevLett.111.183203.pdf: 699711 bytes, checksum: 0da26fa2f8dabf69d8021b58f70a09ec (MD5) Previous issue date: 2013 We report the direct detection of two metastable H(2S2) atoms coming from the dissociation of a single cold H2 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 to the collision center, measure the neutral metastable H(2S2) through a localized quenching process, which mixes the H(2S2) state with the H(2P2), leading to a Lyman-α detection. Our data show the accomplishment of a coincidence measurement which proves for the first time the existence of the H(2S2)-H(2S2) dissociation channel.