Symmetry of Cl2- resonant states formed in dissociative electron attachment reaction on Cl2

The authors have studied Cl- formation by dissociative electron attachment on Cl2, by means of a crossed-beam electron impact spectrometer, in the energy range 0-10 eV. It is shown that the Cl- current exhibits three peaks at zero, 2.5 and around 5.5 eV. An analysis of the measured angular distributions of the Cl- ions, using the O'Malley-Taylor theory (1968) in the PRS-PS approximation, indicates that in the energy range of these peaks Cl- formation proceeds via the 2 Sigma u+, 2 Pi g and 2 Pi u Cl2- resonant states respectively. Furthermore the authors' results do not exclude a small contribution of the 2 Sigma g+Cl2- state to Cl- formation in the low-energy side of the third process.