This is the project page for BaBooNs.
Kaitlin Cook: Parameters
Justin Michael Brown: Code
Rob Almus: Analysis
Aim: Investigate the effects of non-thermal baryon injection on BBN.
Introduction If dark matter particles (e.g. WIMPS) exist, they inevitably did so during the big bang. They also may decay during BBN into non-thermal particles - this may be in the form of photons, leptons (electron/positron pairs and/or neutrinos) or into hadronic channels (n/p, mesons, nuclei). These decays may have two influences into BBN:
1) Change the expansion rate due to the injection of relativistic species.
2) Effect the abundance of light nuclei produced in BBN via reactions with these decay particles.
In case (1), this effect is important only if the decay channels are relativistic, thus adding a lot of entropy into the universe. In this project, we will consider the injection of neutrons, so we will not consider this effect.
It is thus the goal of this project to investigate the effect of the injection of non-thermal neutrons on the light element abundances.
from CDMS in 2004 suggests that this value isn't too far off.
To add in reaction rates, as above, obviously one needs to find some reaction rates. Unfortunately, these don't exist at the temperatures and energy distributions of interest, as far as the authors are aware. Instead, we used the Ramsauer model, with parameters from Gowder et. al. 2005 to find total scattering cross sections. We then took a nominal value of 10% for the destruction cross sections. See the presentation for details. The cross sections were then put into a reaction rate, using a dirac function distribution of neutron energies.
May be found here. presentation_bbn.pdf
Cyburt et. al. 2009. Nucleosynthesis Constraints on a Massive Gravitino in Neutralino Dark Matter Scenario http://arxiv.org/pdf/0907.5003v1.pdf
Kamionkowski 1994. Diffuse Gamma Rays from WIMP Decay and Annihilation http://arxiv.org/pdf/astro-ph/9404079v1.pdf
Pierre Salati, 2014. Dark Matter Annihilation in the Universe http://arxiv.org/pdf/1403.4495.pdf