Interactions between neutrino wave packets

The Standard Model predicts a weak interaction between neutrinos, which may be treated as a Fermi four-point interaction, creating a potential for various consequences in neutrino-dense environments such as core-collapse supernovae. In the event of coherent forward scattering, neutrinos would be able to directly exchange flavor with one another and undergo collective, fast flavor oscillations. Recent studies of collective neutrino oscillations have begun to also consider non-forward scattering as well as the possible physical consequences of neutrino wave packet sizes in simulations. We present a new analysis of neutrino interactions including both of these effects to better resolve their importance in studying fast flavor oscillations.