1993/10/26 by K. S. Babu, Thomas M. Gould, T. M. Gould +2 · 5 citations
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ph
paper · pdf · doi:10.1016/0370-2693(94)90340-9
published as Phys.Lett.B321:140-144,1994 · 8 pgs. LaTeX (1 uuencoded fig., also available on request), Bartol-930XXX, JHU-TIPAC-930026, UM-TH-93-26
arxiv created 1993/10/26 · openalex publication_date 1994/01/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this note, we analyze various constraints on the ``visible'' decay modes of a massive τ neutrino, ντ→ν^′ γ and ντ→ν^′ e+ e-, where ν^′ is a light neutrino. The BEBC beam dump experiment provides model-independent constraints on these modes. The lifetime for the ν^′ e+e- mode is constrained to be τν^′ e+e- ≥ 0.18~(mντ/MeV)~sec. We point out that the same experiment implies a similar constraint on the ν^′ γ mode. This results in a new upper limit on the transition magnetic moment of ντ, μ\rm tran ≤ 1.1 × 10-9 (MeV/mντ)2 μB . Furthermore, a limit on the electric charge of ντ may be obtained, Qντ ≤ 4 × 10-4e. Combining these constraints with those arising from supernova observations and primordial nucleosynthesis calculations, we show that these ``visible'' decays cannot be the dominant decay modes of the τ neutrino.