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

TL;DR

This paper investigates how neutrino signals from supernovae can be used to test for possible violations of Lorentz invariance, providing new sensitivity estimates for quantum gravity effects on neutrino velocities.

Contribution

It introduces a wavelet analysis of supernova neutrino emissions to set bounds on Lorentz violation parameters, surpassing previous estimates from simpler models.

Findings

Sensitivity to Lorentz violation mass scales up to 2 x 10^{13} GeV for linear effects.

Sensitivity to quadratic Lorentz violation mass scales up to 10^6 GeV.

Potential to detect stochastic fluctuations in neutrino propagation times.

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.