PT Journal
AU Hernandez, P
   Kekic, M
   Lopez-Pavon, J
TI N_eff in low-scale seesaw models versus the lightest neutrino mass
SO Physical Review D
JI Phys. Rev. D
PY 2014
BP 065033
EP 12pp
VL 90
IS 6
DI 10.1103/PhysRevD.90.065033
LA English
AB We evaluate the contribution to N_eff of the extra sterile states in low-scale type I seesaw models (with three extra sterile states). We explore the full parameter space and find that at least two of the heavy states always reach thermalization in the early Universe, while the third one might not thermalize provided the lightest neutrino mass is below O(10(-3) eV). Constraints from cosmology therefore severely restrict the spectra of heavy states in the range 1 eV-100 MeV. The implications for neutrinoless double beta decay are also discussed.
ER