Dark Radiation or Warm Dark Matter from long lived particle decays in the light of Planck

作者：Di Bari Pasquale; King Stephen F; Merle Alexander^*

来源：Physics Letters B, 2013, 724(1-3): 77-83.

DOI：10.1016/j.physletb.2013.06.003

Although Planck data supports the standard ACDM model, it still allows for the presence of Dark Radiation corresponding up to about half an extra standard neutrino species. We propose a scenario for obtaining a fractional %26quot;effective neutrino species%26quot; from a thermally produced particle which decays into a much lighter stable relic plus standard fermions. At lifetimes much longer than similar to 1 s, both the relic particles and the non-thermal neutrino component contribute to Dark Radiation. By increasing the stableto-unstable particle mass ratio, the relic particle no longer acts as Dark Radiation but instead becomes a candidate for Warm Dark Matter with mass O(1 keV-100 GeV). In both cases it is possible to address the lithium problem.

• 出版日期2013-7-9