Improved big bang nucleosynthesis constraints on heavy neutral leptons

Big Bang Nucleosynthesis Constraints on Bulk Neutrinos

We examine the constraints imposed by the requirement of successful nucleosynthesis on models with one large extra hidden space dimension and a single bulk neutrino residing in this dimension. We first use naive out of equilibrium conditions to constrain the size of the extra dimensions and the mixing between the active and the bulk neutrino. We then use the solution of the Boltzman kinetic equ...

Big Bang Nucleosynthesis Constraints on Z ′ Properties ∗

In models involving new T eV-scale Z ′ gauge bosons, the new U (1) ′ symmetry often prevents the generation of Majorana masses needed for a conventional neutrino seesaw, leading to three super-weakly interacting " right-handed " neutrinos, the Dirac partners of the ordinary neutrinos. These can be produced prior to Big Bang Nucleosynthesis (BBN) by the Z ′ interactions, leading to a faster expa...

Big-bang nucleosynthesis constraints on dark-matter sectors revisited

C.A. Bertulani, ∗ V. Challa, † J.J. He, 3, ‡ S.Q. Hou, 3, § and Ravinder Kumar 4, ¶ Department of Physics and Astronomy, Texas A & M University-Commerce, Commerce, Texas 75429, USA Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, China Key Laboratory of High Precision Nuclear Spectroscopy, Institute of Modern Physics, Chinese...

Big bang nucleosynthesis constraints on primordial magnetic fields.

We reanalyze the e ect of magnetic elds in BBN, incorporating several features which were omitted in previous analyses. We nd that the e ects of coherent magnetic elds on the weak interaction rates and the electron thermodynamic functions ( e, Pe, and d e=dT ) are unimportant in comparison to the contribution of the magnetic eld energy density in BBN. In consequence the e ect of including magne...

Big Bang Nucleosynthesis