  State-by-state cross sections for dissociative electron attachment and
electron-impact dissociation for molecular oxygen are computed using ab initio
resonance curves calculated with the R-matrix method. When O2 is in its
vibrational ground state, the main contribution for both processes comes from
the $^2\Pi_u$ resonance state of $O_2^-$ but with a significant contribution
from the $^4\Sigma$ resonant state. Vibrational excitation leads to an
increased contribution from the low-lying $^2\Pi_{g}$ resonance, greatly
increased cross sections for both processes, and the threshold moving to lower
energies. These results provide important input for models of O2-containing
plasmas in nonequilibrium conditions.
