Photonic soliton and its relevance to radiative neutrino pair emission

We consider atomic system of $\Lambda-$type 3-level coupled to 2 mode fields, and derive an effective Maxwell-Bloch equation designed for two photon emission between two lower levels. We find axially symmetric, topologically stable soliton solutions made of condensed fields. Immediate implication of soliton formation to radiative neutrino pair emission is to enhance its rate, larger than the usual $\propto N^2$ factor of target number dependence, along with another merit of increasing the signal to the background photon emission.