Title:i Recoilless Neutrinos: Promise and Problems


Antineutrinos from bound state β-decay of tritium (T) can be resonantly captured in 3He. With T and 3He embedded in metal tritides, recoilless resonant capture of ultra sharp (DeltaE/E ~10-16) 18.6 keV antineutrinos from T may be possible with the effective cross section \sigma(res) ~1.3x10-32 cm2, ten orders of magnitude larger than that for conventional antineutrino detection. The experimental constraints are extremely severe, however, a specific road map based on state-of-the-art tritide science and technology is emerging. Because of the low antineutrino energy and high \sigma(res), the new technique could reveal the νantineutrino gravitational red shift, test antineutrino conversion to sterile nineutrinos and eventually, search for θ13antineutrno flavor oscillations, all in bench-scale baselines.