Year: 2026
Type: dissertation
Abstract: The first half of this study extends the Monte Carlo code Cosmion to account for the continuous flux of dark matter particles from the galactic halo. This step is crucial to quantifying the non-equilibrium population of dark matter, in contrast to previous studies where only the equilibrium population has been considered. Spin- dependent scattering is considered in the Sun for mχ = 5, 10, 15, and 20 GeV, with spin-independent scattering in the Earth for mχ = 20, 50, 75, and 100 GeV covering cross-sections 10−38 to 10−32 cm2. Capture rates, reflection fraction, and the spatial distribution are extracted and compared against the formalism of [1, 2]. The sim- ulations deliberately target the non-equilibrium population and reveal two distinct regimes: (1) an optically thick random-walk plateau at large cross section (2) orbital lock at small cross section. In the second, the 55Mn nuclear de-excitation channel is used to search for ALPs from Betelgeuse. Archival INTEGRAL observations are analyzed for a line signal from Primakoff conversion and from axion decay, yielding limits on the axion-photon and axion-nucleon couplings. This provides an improvement or complements the corresponding 57Fe channel, and a projected Asimov sensitivity for AMEGO-X is derived
Author: Grewal, Baldeep
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7219301765