M\"ossbauer Antineutrinos: Recoilless Resonant Emission and Absorption of Electron Antineutrinos

Basic questions concerning phononless resonant capture of monoenergetic electron antineutrinos (M\"ossbauer antineutrinos) emitted in bound-state beta-decay in the 3H - 3He system are discussed. It is shown that lattice expansion and contraction after the transformation of the nucleus will drastically reduce the probability of phononless transitions and that various solid-state effects will cause large line broadening. As a possible alternative, the rare-earth system 163Ho - 163Dy is favoured. M\"ossbauer-antineutrino experiments could be used to gain new and deep insights into several basic problems in neutrino physics

Recoilless resonant neutrino experiment and origin of neutrino oscillations

We demonstrate that an experiment with recoilless resonant emission and absorption of tritium antineutrinos could have an important impact on our understanding of the origin of neutrino oscillations.Comment: The report at the Workshop on Next Generation Nucleon Decay and Neutrino Detectors, NNN06, September 21-23, 2006, University of Washington, Seattle, US

Attenuation measurements of vacuum ultraviolet light in liquid argon revisited

The attenuation of vacuum ultraviolet light in liquid argon in the context of its application in large liquid noble gas detectors has been studied. Compared to a previous publication several technical issues concerning transmission measurements in general are addressed and several systematic effects were quantitatively measured. Wavelength-resolved transmission measurements have been performed from the vacuum ultraviolet to the near-infrared region. On the current level of sensitivity with a length of the optical path of 11.6 cm, no xenon-related absorption effects could be observed, and pure liquid argon is fully transparent down to the short wavelength cut-off of the experimental setup at 118 nm. A lower limit for the attenuation length of pure liquid argon for its own scintillation light has been estimated to be 1.10 m based on a very conservative approach.Comment: 14 pages, 22 figure

Neutrino oscillations and uncertainty relations

We show that coherent flavor neutrino states are produced (and detected) due to the momentum-coordinate Heisenberg uncertainty relation. The Mandelstam-Tamm time-energy uncertainty relation requires non-stationary neutrino states for oscillations to happen and determines the time interval (propagation length) which is necessary for that. We compare different approaches to neutrino oscillations which are based on different physical assumptions but lead to the same expression for the neutrino transition probability in standard neutrino oscillation experiments. We show that a Moessbauer neutrino experiment could allow to distinguish different approaches and we present arguments in favor of the 163Ho-163Dy system for such an experiment.Comment: Some small changes in section 2, results unchanged. Added referenc