Phenomenology of Astrophysical Neutrinos

Arizona State University, Scottsdale AZ

Investigators

Abstract

This project sits at the boundary between theoretical nuclear physics and particle astrophysics. Specifically, this research concerns the physics of neutrinos, elementary particles that are produced abundantly in stars and galaxies. These "astrophysical" neutrinos have been observed at Earth already and many more observations are expected in the near future. In this context, the theoretical research to be performed by the PI will play an important role in understanding the experimental data and will allow for new insights regarding the fundamental processes that take place in stars and the specific role played by the neutrino properties. In addition, this state-of-the-art research project will provide excellent opportunities for the training of students. A major area of investigation in particle astrophysics concerns the physics of O(10) MeV neutrinos from core-collapse supernovae that presents a strategic opportunity for upcoming neutrino detectors. It is planned to study the potential of these detectors to measure the oscillation probabilities of neutrinos from a galactic supernova burst, with minimal theoretical priors, to distinguish different oscillation scenarios. Hours before a star becomes a supernova, neutrinos from the Silicon burning phase might be detectable. The flux of these neutrinos will be modeled in detail, using a new calculation method that includes the nuclear beta processes. Supernova neutrinos can also be detected in the form of diffuse flux from the cosmic population of supernovae. The study of this flux will be revitalized in the light of recent developments, with focus on detectability, and on the potential to measure important physical quantities from the diffuse flux. At higher energies, E ~ TeV - PeV, extraterrestrial neutrinos were discovered in 2013. This project considers star formation as a possible origin of these neutrinos. Positional coincidences of the neutrino data with known high-star formation regions will be studied quantitatively, and theory models of neutrino production in these regions will be developed. This project is co-funded by the Division of Physics and the Division of Astronomical Sciences in the Directorate of Mathematical & Physical Sciences.