Neutrino-nucleon scattering in the neutrino-sphere

Understand

We calculate the differential scattering rate for thermal neutrinos in a hot and dilute gas of interacting neutrons using linear response theory.

• The dynamical structure factors for density and spin fluctuations of the strongly interacting neutron matter, expected in the neutrino decoupling regions of supernovae and neutron star mergers, are calculated in the virial expansion for the first time.
• Correlations due to nucleon-nucleon interactions are taken into account using a pseudo-potential that reproduces measured nucleon-nucleon phase shifts, and we find that attractive s-wave interactions enhance the density response and suppress the spin response of neutron matter.
• The net effect of neutron correlations is to strongly suppress backscattering.