Master thesis: Thermalisation of inelastic dark matter in the Sun with a light mediator
Thursday 23 August 2018
to 16:00 at
Simon Israelsson (Particle and Astroparticle Physics, Physics, KTH)
Particle dark matter is a popular solution to the missing mass problem present in the Universe. If dark matter interacts with ordinary matter, even very weakly, it might be the case that it is captured and accumulated in the Sun, where it may then annihilate into particles that we can observe here on Earth. The interaction between dark matter and standard model particles may be mediated by a light dark sector particle. This would introduce an extra recoil energy suppression into the scattering cross section for collision events, which is of the form needed to possibly also alleviate some of the observed small scale structure issues of collisionless cold dark matter. In this work we perform numerical simulations of the capture and subsequent scattering of inelastic dark matter in the Sun, in the presence of a light mediator particle. We find that the presence of the mediator results in a narrower capture region than expected without it and that it mainly affects the scattering rate in the phase space region where the highest scattering rates are found. However, it is not seen to cause any noticeable difference to the radial distribution of dark matter in the Sun. No steady state is reached and the captured dark matter does not reach thermal equilibrium in the Sun.