Talent

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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.

Key parameters:

1. The mean life of the decaying particle X → 2n (some magic decay. Not very physical, probably. But hey, we don't actually know what WIMPS are).
2. The energy of these neutrons (although if it is high enough, it may not matter too much?)
3. The abundance of X.
4. n interaction rates with every other nucleus.
5. Mass of the WIMP. Chosen to be 100 GeV, based on the wikipedia WIMP entry, the font of all wisdom.

This figure:

from CDMS in 2004 suggests that this value isn't too far off.

Reference Papers:

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

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