1999/09/17 by Kevork Abazajian, Abazajian, Kevork, Xiangdong Shi +3
Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #astro-ph #hep-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9909320
12 pages, including 4 figures, submitted to Phys. Rev. D
arxiv created 1999/09/17 · arxiv updated 2009/11/30
We examine in detail the changes in the production of primordial helium resulting from nonthermal neutrino momentum distributions produced by resonant transformation of electron-type neutrinos to steriles. These transformations, anti-nue -> anti-nus (nue->nus), amplify a positive (negative) lepton number asymmetry. We find that the resulting supression relative to a thermal distribution of low energy nue reduces n -> p conversion to a greater extent than does the enhancement of n -> p from an identical suppression of anti-nue. Thus, equal lepton-number asymmetries of opposite sign have unequal effects on the resulting helium yield in primordial nucleosynthesis.