Analyzing the time spectrum of supernova neutrinos to constrain their effective mass or Lorentz Invariance Violation

Abstract

We analyze the expected arrival time spectrum of supernova neutrinos using simulated luminosity and compute the expected number of events in future detectors such as the DUNE Far Detector and Hyper-Kamiokande. We develop a general method using minimum square statistics that can compute the sensitivity to any variable affecting neutrino time of flight. We apply this method in two different situations: First, we compare the time spectrum changes due to different neutrino mass values to put limits on electron (anti)neutrino effective mass. Second, we constrain Lorentz invariance violation through the mass scale, $M_{QG}$, at which it would occur. We consider two main neutrino detection techniques: 1. DUNE-like liquid argon TPC, for which the main detection channel is $ν_e +\, ^{40}\mbox{Ar} \rightarrow e^- +\, ^{40}\mbox{K}^*$, related to the supernova neutronization burst; and 2. HyperK-like water Cherenkov detector, for which $\bar ν_e + p \rightarrow e^+ + n$ is the main detection channel. We consider a fixed supernova distance of 10~kpc and two different masses of the progenitor star: (i) 15~$M_\odot$ with neutrino emission time up to 0.3~s and (ii) 11.2~$M_\odot$ with neutrino emission time up to 10~s. The best mass limits at 3$σ$ are for $\mathcal{O}(1)$~eV. For $ν_e$, the best limit comes from a DUNE-like detector if the mass ordering happens to be inverted. For $\bar ν_e$, the best limit comes from a HyperK-like detector. The best limit for the Lorentz invariance violation mass scale at the 3$σ$ level considering a superluminal or subluminal effect is $M_{QG} \gtrsim 10^{13}$~GeV ($M_{QG} \gtrsim 5 \times 10^{5}$~GeV) for linear (quadratic) energy dependence.