Classical and Quantum Coherent State Description of Nucleon-Antinucleon   Annihilation at Rest in the Skyrme Model with Omega Mesons
  We model the $N\bar{N}$ system at rest as a baryon number zero lump in the Skyrme model including the $\omega$ field. We integrate the classical equations of motion from the highly non-perturbative annihilation region into the non-interacting radiation zone. Subsequent coherent state quantization of the radiation field gives a good description of the pion spectrum from annihilation at rest. 
Bin Shao and R. D. Amado