A future cosmological survey reports at 95 percent confidence

PHYSICS · Subjective · Fermi University Physics · Particle Physics & Quantum Fields · Flavour, neutrinos and CP violation · Flavour, neutrinos and CP violation

Symmetry and Flavour, Ch Neutrino masses, mixing and oscillations

Problem

A future cosmological survey reports

\sum m_\nu < 0.08\,\mathrm{eV}

at 95 percent confidence. Using the NuFIT 6.0 (2024) splittings

\Delta m^2_{21} = 7.49\times10^{-5}\,\mathrm{eV^2}

and

\Delta m^2_{31} = 2.513\times10^{-3}\,\mathrm{eV^2}

, and taking the lightest neutrino mass to be exactly zero in each ordering, the minimum possible mass sums are

0.059\,\mathrm{eV}

for the normal ordering and

0.099\,\mathrm{eV}

for the inverted ordering. State which ordering, if any, the quoted bound disfavours, and explain your reasoning in one sentence.

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