Probing neutrino-matter interaction rates in neutron star mergers

Neutron star-neutron star and neutron star-black hole binaries are the most well-known systems to generate both gravitational wave and electromagnetic signals. Our ability to analyze the observational data obtained from these systems heavily relies on numerical simulations that incorporate varied physical processes including general relativity, neutrino radiation transport and magnetohydrodynamics. The evolution of the neutrino transport equations still requires significant approximations in current simulations. This is potentially problematic when analyzing kilonovae to get deeper insights into the nature of the matter ejected by mergers as well as when studying the contribution of ejecta to the nucleosynthesis of elements. One important source of uncertainty is the use of approximate neutrino-matter interaction rates. The current study aims to analyze relative reaction rates from standard charged current, elastic scattering reactions, pair processes and inelastic scatterings on 3D snapshots of a SpEC merger simulation using the NuLIB library, in order to identify regions in which various reactions matter.