We present a new strategy for measuring the electron neutrino mass (\mnue)
by future detection of a Galactic supernova in large underground detectors such
as the Super-Kamiokande (SK). This method is nearly model-independent and one
can get a mass constraint in a straightforward way from experimental data
without specifying any model parameters for profiles of supernova neutrinos. We
have tested this method using virtual data generated from a numerical model of
supernova neutrino emission by realistic Monte-Carlo simulations of the SK
detection. It is shown that this method is sensitive to \mnue of ∼ 3 eV
for a Galactic supernova, and this range is as low as the prediction of the
cold+hot dark matter scenario with a nearly degenerate mass hierarchy of
neutrinos, which is consistent with the current observations of solar and
atmospheric neutrino anomalies and density fluctuations in the universe.Comment: 4 pages including 1 figure, accepted by Phys. Rev. Let
