New upper limits on the tau-neutrino mass from primordial helium considerations

Journal Article · Mon Jul 26 00:00:00 EDT 1993 · Physical Review Letters; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.71.476· OSTI ID:6217001

Dolgov, A D; Rothstein, I Z ^[1]

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1. The Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109 (United States)

In this paper we reconsider recently derived bounds on MeV tau neutrinos, taking into account previously unaccounted for effects. We find that, assuming that the neutrino lifetime is longer than [similar to]100 sec, the constraint [ital N][sub eff][lt]3.6 rules out [nu][sub [tau]] masses in the range 0.5[lt][ital m][sub [nu][tau]][lt]35 MeV for Majorana and 0.3[lt][ital m][sub [nu][tau]][lt]35 MeV for Dirac neutrinos. Given that the present laboratory upper bound is 31 MeV, our results imply an upper bound of 0.5 MeV for Majorana neutrinos and of 0.3 MeV for Dirac neutrinos.

• OSTI ID: 6217001
• Journal Information: Physical Review Letters; (United States), Vol. 71:4; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Pa
MASS
LIMITING VALUES
TAU NEUTRINOS
ABUNDANCE
HELIUM
LIFETIME
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FLUIDS
GASES
HEAVY LEPTONS
LEPTONS
MASSLESS PARTICLES
NEUTRINOS
NONMETALS
POSTULATED PARTICLES
RARE GASES
662210* - Specific Theories & Interaction Models
Particle Systematics- Unified Theories & Models- (1992-)
662430 - Properties of Leptons- (1992-)