NONLINEAR NEUTRINO PLASMAS INTERACTIONS

A new interaction mechanism is described between neutrinos and dense p lasmas. With the unification of the electromagnetic and weak forces, a nalogous processes should occur for intense neutrino fluxes as for pho ton fluxes. Intense EM waves excite parametric instabilities in nonlin ear media and plasma in particular. Therefore, sufficiently intense ne utrino fluxes should also cause similar parametric instabilities in de nse plasmas. An important example is the production of Langmuir plasmo ns and lower energy neutrinos. In plasma physics, for electromagnetic waves, the process is known as stimulated Raman scattering and it grea tly increases the interaction of the light with the plasma. We propose that the analogous process, for neutrinos, occurs in the plasma surro unding the core of a supernova due to the immense neutrino flux there and the fact that at some distance from the core the flux is strongly unidirectional. We develop a theory for stimulated scattering of neutr inos in plasmas based on the index of refraction for neutrinos which d epends on electron density, conservation of energy and momentum for ne utrinos plus plasmons and wave damping; we estimate approximate growth rates.