Bounds on Dirac neutrino masses from nucleosynthesis

Journal Article · Sat Apr 15 00:00:00 EDT 1995 · Physical Review, D (Particles Fields); (United States)

DOI:https://doi.org/10.1103/PhysRevD.51.4129· OSTI ID:6474343

Dolgov, A D ^[1]; Kainulainen, K ^[2]; Rothstein, I Z ^[3]

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1. Institute of Theoretical and Experimental Physics, Moscow 117259 (Russian Federation) NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States) Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States)
2. School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)
3. Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States)

We derive new bounds on the Dirac mass of the tau and muonic neutrinos. By solving the kinetic equation for the rate of energy deposition due to helicity-flipping processes and imposing the constraint that the number of effective species contributing to the energy density at the time of nucleosynthesis be [Delta][ital k][sub [nu]][lt]0.3, we find the bounds [ital m][sub [nu][mu]][lt]150 keV and [ital m][sub [nu][tau]][lt]190 keV for [ital T][sub QCD]=200 MeV. The constraint [Delta][ital k][sub [nu]][lt]0.1 leads to the much stronger bound [ital m][sub [nu]][lt]10 keV for both species of neutrinos.

• DOE Contract Number: AC02-83ER40105
• OSTI ID: 6474343
• Journal Information: Physical Review, D (Particles Fields); (United States), Vol. 51:8; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
MASS
CONSTRAINTS
MUON NEUTRINOS
TAU NEUTRINOS
DIRAC OPERATORS
ENERGY DENSITY
ENERGY DEPOSITION
HELICITY
KINETIC EQUATIONS
NUCLEOSYNTHESIS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
HEAVY LEPTONS
LEPTONS
MASSLESS PARTICLES
MATHEMATICAL OPERATORS
NEUTRINOS
PARTICLE PROPERTIES
POSTULATED PARTICLES
QUANTUM OPERATORS
SYNTHESIS
662430* - Properties of Leptons- (1992-)