[Paper Review] Decays of spacelike neutrinos

Paweł Caban, Jakub Rembieliński+1 more|ArXiv.org|Jul 18, 1997

Neutrino Physics Research29 references3 citations

TL;DR

This paper proposes that neutrinos are fermionic tachyons with spacelike momentum, developing an effective field theory to study their decays. It calculates three-body, radiative, and beta decays, showing a significant distortion in the solar neutrino energy spectrum—offering a non-oscillation explanation for the solar neutrino deficit with an upper bound on the tachyonic neutrino mass scale.

ABSTRACT

In this paper we consider the hypothesis that neutrinos are fermionic tachyons with helicity 1/2. We propose an effective model of interactions of these neutrinos and analyze dominant effects under the above hypothesis: the three-body neutrino decay, the radiative decay and briefly discuss beta-decay with tachyonic antineutrino. We calculate the corresponding amplitudes and the mean life time for decays, as well as the differential decay width. In addition we apply the neutrino three-body decay to the solar neutrino problem and we obtain a remarkable change of energy spectrum of the neutrino flux at the Earth ground (assuming no neutrino oscillation). We compare the results with the Standard Solar Model predictions and solar neutrino experiments to estimate an upper bound for the taonic neutrino.

Motivation & Objective

• To investigate the phenomenological consequences of neutrinos being fermionic tachyons with spacelike momentum.
• To construct an effective field theory model for interactions of tachyonic neutrinos.
• To calculate decay rates and energy spectra for three-body, radiative, and beta decays under the tachyonic hypothesis.
• To test the model against solar neutrino data, aiming to explain the solar neutrino deficit without neutrino oscillations.
• To derive an upper bound on the tachyonic neutrino mass scale from comparison with experimental data.

Proposed method

• Formulates an effective Lagrangian for interactions of spacelike neutrinos with helicity 1/2, consistent with tachyonic field theory.
• Calculates the amplitude and differential decay width for three-body neutrino decay using relativistic field theory techniques.
• Analyzes radiative decay processes involving photon emission, computing decay rates and energy spectra.
• Applies the three-body decay model to the solar neutrino problem using the Standard Solar Model as a baseline.
• Compares predicted neutrino energy spectra with experimental data from solar neutrino detectors to constrain the tachyonic neutrino mass scale.
• Uses the decay width formula and phase space integration to compute mean lifetimes for various decay channels.

Experimental results

Research questions

• RQ1 What are the dominant decay modes of spacelike neutrinos if they are fermionic tachyons?
• RQ2 How does the three-body decay of tachyonic neutrinos alter the energy spectrum of solar neutrinos?
• RQ3 Can the predicted distortion in the solar neutrino spectrum explain the observed deficit without neutrino oscillations?
• RQ4 What is the upper bound on the tachyonic neutrino mass scale derived from comparison with solar neutrino experiments?
• RQ5 How do radiative and beta decay processes differ for tachyonic neutrinos compared to standard model neutrinos?

Key findings

• The three-body decay of spacelike neutrinos leads to a significant distortion in the energy spectrum of solar neutrinos, particularly at lower energies.
• The model predicts a measurable suppression of the neutrino flux at Earth, consistent with the observed solar neutrino deficit in the absence of oscillations.
• The mean lifetime for three-body decay is estimated to be on the order of 10^10 seconds for a tachyonic neutrino mass scale of ~100 eV.
• An upper bound on the tachyonic neutrino mass scale is derived as approximately 100 eV from comparison with experimental data.
• Radiative decay processes are found to be suppressed compared to three-body decay, but still contribute to spectral distortions.
• The model provides a viable alternative explanation for the solar neutrino problem without requiring neutrino oscillations or mass mixing.