| Abstract: Recently new reactor antineutrino spectra have been provided
for 235U, 239Pu, 241Pu and 238U, increasing the mean flux by about 3 percent.
With the new flux evaluation the synthesis of published experiments at
reactor-detector distances <100 m leads to a ratio of 0.943(0.023),
leading to a deviation from unity at 98.6% C.L. that we call the reactor
antineutrino anomaly. The compatibility of our results with the existence
of a fourth non-standard neutrino state driving neutrino oscillations at
short distances will be discussed. The combined analysis of reactor data,
gallium solar neutrino calibration experiments disfavors the no-oscillation
hypothesis at 99.8% C.L. The oscillation parameters are such that |Delta
m_{new}^2|>1.5 eV^2 (99%) and sin^2(2theta_{new}) = 0.14(0.1) (95%).
I will show that this hypothesis can be tested with a PBq (ten kilocurie
scale) 144Ce or 106Ru antineutrino beta-source deployed at the center of
a large low background liquid scintillator detector. In particular, the
compact size of such a source could yield an energy-dependent oscillating
pattern in event spatial distribution that would unambiguously determine
neutrino mass differences and mixing angles. |