Constraints on the relic neutrino abundance and implications for cosmological neutrino mass limits

Bell, Nicole F.

Fermi National Accelerator Laboratory

关键词: Abundance;    Lepton Number;    71 Classical And Quantum Mechanics, General Physics;    72 Physics Of Elementary Particles And Fields;    Astrophysics;   

DOI  :  10.2172/879071
RP-ID  :  FERMILAB-FN-0785-A
RP-ID  :  AC02-76CH03000
RP-ID  :  879071

美国|英语

来源: UNT Digital Library

【 摘 要 】

The authors examine a mechanism which can lead to flavor transformation of neutrino-antineutrino asymmetries in the early universe, a process which is unavoidable when the neutrino mixing angles are large. This sets the best limit on the lepton number of the universe, and hence on the relic neutrino abundance. They also consider the consequences for the relic neutrino abundance if extra neutrino interactions are allowed, e.g., the coupling of the neutrinos to a light (compared to m{sub {nu}}) boson. For a wide range of couplings not excluded by other considerations, the relic neutrinos would annihilate to bosons at late times, and thus make a negligible contribution to the matter density today. This mechanism evades the neutrino mass limits arising from large scale structure.