Probing Lorentz Violation in Neutrino Propagation from a Core-Collapse Supernova

Abstract

Supernova explosions provide the most sensitive probes of neutrino propagation, such as the possibility that neutrino velocities might be affected by the foamy structure of space-time thought to be generated by quantum-gravitational (QG) effects. Recent two-dimensional simulations of the neutrino emissions from core-collapse supernovae suggest that they might exhibit variations in time on the scale of a few milliseconds. We analyze simulations of such neutrino emissions using a wavelet technique, and consider the limits that might be set on a linear or quadratic violation of Lorentz invariance in the group velocities of neutrinos of different energies, v/c = [1 \pm (E/M_{nuLV1})] or [1 \pm (E/M_{\nuLV2})^2], if variations on such short time scales were to be observed, where the mass scales M_{nuLVi} might appear in models of quantum gravity. We find prospective sensitivities to M_{nuLV1} ~ 2 X 10^{13} GeV and M_{nuLV2} ~ 10^6 GeV at the 95% confidence level, up to two orders of magnitude beyond estimates made using previous one-dimensional simulations of core-collapse supernovae. We also analyze the prospective sensitivities to scenarios in which the propagation times of neutrinos of fixed energies are subject to stochastic fluctuations.