Department of Physics Calendar
Physics Colloquium: Jim Kneller
Title: Neutrinos in and from Supernovae
Ninety-nine percent of the energy released in a core-collapse supernova is emitted in the form of neutrinos. Due to their central role in the supernova paradigm, our understanding of these stellar explosions ultimately rests upon our understanding of one of nature’s most ephemeral particles. The phenomena of neutrino flavor oscillations changes one type of neutrino into the others as the neutrino propagates however at the present time, even the most sophisticated, multi-dimensional simulations of core-collapse supernovae do not (self-consistently) include neutrino flavor transformation. The present state-of-the-art, known as the BULB model, post-processes a simulation thus any flavor transformation cannot be fed back into the dynamics of the explosion. If the dynamics are changed, the signal we receive from the next supernova in the Milky Way will also be changed.
In this talk I will present the main thrusts of the research undertaken by the group at NC State into supernova neutrinos: going beyond the BULB model, and neutrino signals from supernovae. I will present the first hydrodynamic core-collapse supernova simulation which simultaneously includes flavor transformation of the free-streaming neutrinos in the neutrino transport. The oscillation calculations are dynamically updated and evolve self-consistently alongside the hydrodynamics. Using a 20 Msun progenitor, I will quantify the changes to the neutrino emission and the heating rates and show that flavor transformation alone does not lead to a successful explosion of this progenitor in spherical symmetry. I will then move on to neutrino signals and demonstrate the newly completed SNEWPY software package written for the SNEWS 2.0 collaboration. With this software we are able to connect many hundreds of simulations with the signals they produce in neutrino detectors on Earth allowing for a quantum leap in the quality of studies examining the physics sensitivity of future Galactic supernova observations.
Host: Department of Physics