Title:	New astrophysical constraint on radiatively decaying neutrinos
Authors:	Sethi, S.K.
Keywords:	Decays of heavy neutrinos Electromagnetic decays Intergalactic matter quasar absorption and emission-line systems Lyman forest
Issue Date:	1996
Publisher:	American Physical Society
Citation:	Physical Review D, 1996, Vol.54, p1301
Abstract:	We calculate constraints on radiatively decaying neutrinos from the recent detection of singly ionized helium in the diffuse intergalactic medium (IGM) at z~=3.3. We consider a model in which neutrinos predominantly decay into invisible relativistic particles with a rate τ-1, and with a small branching ratio into the radiative mode. To satisfy the observation, which puts a lower bound on the number density of singly ionized helium atoms in the IGM, we show that, for τ>~1018 sec (1 eV/m2ν), transition moment of neutrinos, μ12, is constrained to be <=4-8×10-17 μB for 110 eV<~mν<~10 keV. Implications of this bound for particle physics and cosmology are briefly discussed.
Description:	Restricted Access
URI:	http://hdl.handle.net/2289/4936
ISSN:	1550-7998 1550-2368(Online)
Alternative Location:	http://adsabs.harvard.edu/abs/1996PhRvD..54.1301S http://arxiv.org/abs/astro-ph/9507116 http://dx.doi.org/10.1103/PhysRevD.54.1301
Copyright:	1996 American Physical Society
Appears in Collections:	Research Papers (A&A)

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