Neutrino-pair bremsstrahlung in collisions between neutrons and nuclei in neutron star matter

In neutron star matter over the density range 4.3×1011<-ϱ≤4×1014 g cm−3 there are both free neutrons and neutron-rich nuclei. If there is a weak neutral current interaction between neutrinos and neutrons, as suggested by recent experiments, then when neutrons scatter off nuclei they may emit$$v\bar v$$ pairs as bremsstrahlung radiation. We calculate the associated emissivity for degenerate (but not superfluid) neutrons and uncorrelated (not crystallized) nuclei. We find that, under these conditions. this emissivity can under some conditions compare with that calculated by Festa and Ruderman for$$v\bar v$$ bremsstrahlung in electron-nucleus collisions.