Statistical analysis of neutrino events from SN1987A neutrino burst: estimation of the electron antineutrino mass

TL;DR

This paper uses statistical analysis of neutrino data from SN1987A to estimate the electron antineutrino mass, suggesting it is around 22 eV/c^2 with an upper limit near 2 eV/c^2, aligning with laboratory measurements.

Contribution

It introduces a novel statistical method analyzing neutrino event correlations to estimate the electron antineutrino mass from supernova data.

Findings

Estimated electron antineutrino mass is approximately 22 eV/c^2.

Mass less than 2 eV/c^2 is unlikely based on the analysis.

Results are consistent with laboratory tritium beta-decay data.

Abstract

The method of the statistical sample moments was used for the analysis of neutrino events from SN1987A burst in Cherenkov detectors. In particular the coefficients of correlation $Q(E,t)$ between the energies $E$ of electron antineutrinos $\bar \nu_e$ emitted by star and the ejection instants $t$ of $\bar \nu_e$ for neutrino events recorded by Cherenkov water detectors of KII and IMB collaborations were calculated. $Q(E,t)$ values depend on the assumed mass of $\bar \nu_e$. Modern model of the gravitational stellar core collapse with an accretion phase predicts the low level of such correlation $<Q(E,t)>$ averaged with respect to neutrino burst. On condition that empirical $Q(E,t)$ values equal the theoretical model quantities $<Q(E,t)>$ one can obtain $22\pm10 eV/c^{2}$ as an estimate of the nonzero $\bar \nu_e$ mass. The error of this estimate implies that $\bar \nu_e$ mass less than $2 eV/c^2$ is unlikely. The laboratry data of the tritium $\beta$-decay agree adequately with the presented astrophysical estimate provided that the anomalous structure near the end point of $\beta$-spectrum is taken into account.