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Title: Massive [tau] neutrino and SN 1987A

Journal Article · · Physical Review, D (Particles Fields); (United States)
 [1];  [2]
  1. Department of Astronomy Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637-1433 (United States) NASA/Fermi Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510-0500 (United States)
  2. Department of Astronomy Astrophysics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637-1433 (United States) NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510-0500 (United States) Department of Physics, Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637-1433 (United States)

The emission of MeV-mass [tau] neutrinos from newly formed neutron stars is considered in a simple, but accurate, model based upon the diffusion approximation. The [tau]-neutrinosphere temperature is found to increase with mass so that the emission of massive [tau] neutrinos is not suppressed by the Boltzmann factor previously used, ([ital m][sub [nu]]/[ital T][sub [nu]])[sup 1.5]exp([minus][ital m][sub [nu]]/[ital T][sub [nu]]), where [ital T][sub [nu]][similar to]4 MeV--8 MeV. For short [tau] neutrino lifetimes ([tau][sub [nu]][approx lt]10[sup [minus]3] sec) decays and inverse decays lead to a reduction in the temperature of the [tau] neutrinosphere. Using our results, we revise limits to the mass and lifetime of an MeV-mass [tau] neutrino based upon SN 1987A. Our constraints, together with bounds based upon primordial nucleosynthesis and laboratory experiments, exclude the possibility of a [tau] neutrino more massive than 0.4 MeV if the dominant decay mode is radiative and [tau][sub [nu]][approx gt]2.5[times]10[sup [minus]12] sec ([ital m][sub [nu]]/MeV). The lifetime restriction does not apply for the modes [nu][sub [tau]][r arrow][nu][sub [ital e],[mu]]+[gamma]. Our technique and results are easily generalized to other hypothetical MeV-mass particles whose interactions are of roughly weak strength. Finally, we speculate on the possible role a 15 MeV--30 MeV [tau] neutrino might play in powering supernova explosions.

OSTI ID:
6852739
Journal Information:
Physical Review, D (Particles Fields); (United States), Vol. 51:4; ISSN 0556-2821
Country of Publication:
United States
Language:
English