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- | This is the project page for BaBooNs. | + | **This is the project page for BaBooNs. ** |
Kaitlin Cook: Parameters | Kaitlin Cook: Parameters | ||
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Rob Almus: Analysis | Rob Almus: Analysis | ||
- | Investigate the effects of non-thermal baryon injection on BBN. | + | **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. | ||
+ | |||
+ | **Key parameters: ** | ||
+ | |||
+ | - 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). | ||
+ | - The energy of these neutrons (although if it is high enough, it may not matter too much?) | ||
+ | - The abundance of X. | ||
+ | - n interaction rates with every other nucleus. | ||
+ | - Mass of the WIMP. Chosen to be 100 GeV, based on the wikipedia WIMP entry, the font of all wisdom. | ||
+ | |||
+ | This figure: | ||
+ | |||
+ | {{::cdms_parameter_space_2004.png?600|}} | ||
+ | |||
+ | 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]] | ||
+ | |||
+ | **Logbook** |