Nucleosynthesis of Heavy Element

Halo Star Abundances and Heavy Element Nucleosynthesis

Abundance observations of neutron-capture elements in halo stars are providing a wealth of new information on the nature of heavy element nucleosynthesis in evolved stars. In particular these observations provide clues and constraints to the synthesis mechanisms for the n-capture elements, suggestions for the site (or sites) for the r-process and Galactic chemical evolution. We have been obtain...

A Sterile Neutrino Needed for Heavy-element Nucleosynthesis

A neutrino mass-mixing scheme which successfully avoids the “alpha effect,” allowing r-process nucleosynthesis in the neutrino-heated ejecta of supernovae, quite independently requires the same parameters as the scheme which best fits all current indications for neutrino mass. The significance for particle physics is this independent evidence for (1) at least one light sterile neutrino, νs; (2)...

Light Element Nucleosynthesis

Primordial Nucleosynthesis, Majorons and Heavy Tau Neutrinos

We determine the restrictions imposed by primordial nucleosynthesis upon a heavy tau neutrino, in the presence of ντ annihilations into Majorons, present in a wide class of particle physics models of neutrino mass. We display these cosmological limits as functions ofmντ and the ντ -ντ -Majoron coupling g. We show that for theoretically plausible g values ∼ 10 present nucleosynthesis observation...

Big Bang Nucleosynthesis : an accurate determination of light element yields

We report the results of a new accurate evaluation of light nuclei yields in primor-dial nucleosynthesis. All radiative effects, finite nucleon mass, thermal and plasma corrections are included in the proton to neutron conversion rates. The relic densities of 4 He, D and 7 Li have been numerically obtained via a new updated version of the standard BBN code. In particular the theoretical uncerta...