Speaker
Description
Dark matter (DM) may naturally exhibit inelastic structure, with small mass splittings between states arising from symmetry breaking. In such scenarios, the lightest DM state can upscatter to a heavier state that subsequently decays semi-visibly, producing secondary photon fluxes. Compact objects—such as neutron stars and white dwarfs—provide efficient environments for these processes, enabling distinctive observational signatures.
We investigate these signatures by studying DM capture and upscattering in compact stars, incorporating a detailed treatment of particle geodesics prior to decay, as well as corrections accounting for the fraction of emitted photons that are reabsorbed upon intersecting the stellar surface.
As an illustration, we consider a benchmark dipole portal DM model and focus on stars in the vicinity of Sagittarius A*. We show that the resulting X-ray signals can lie within the reach of current and future observatories, including Chandra X-ray Observatory, XMM-Newton, and NuSTAR. The inferred astrophysical sensitivity is highly competitive with traditional accelerator-based searches for light dark sectors.
| Other topic / keywords: | compact objects |
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