The impact of the Large Magellanic Cloud on dark matter direct detection signals

Smith-Orlik, Adam; Ronaghi, Nima; Bozorgnia, Nassim; Cautun, Marius; Fattahi, Azadeh; Besla, Gurtina; Frenk, Carlos S.; Garavito-Camargo, Nicolás; Gómez, Facundo A.; Grand, Robert J.J.; Marinacci, Federico; Peter, Annika H.G.

Abstract

We study the effect of the Large Magellanic Cloud (LMC) on the dark matter (DM) distribution in the Solar neighborhood, utilizing the Auriga magneto-hydrodynamical simulations of Milky Way (MW) analogues that have an LMC-like system. We extract the local DM velocity distribution at different times during the orbit of the LMC around the MW in the simulations. As found in previous idealized simulations of the MW-LMC system, we find that the DM particles in the Solar neighborhood originating from the LMC analogue dominate the high speed tail of the local DM speed distribution. Furthermore, the native DM particles of the MW in the Solar region are boosted to higher speeds as a result of a response to the LMC's motion. We simulate the signals expected in near future xenon, germanium, and silicon direct detection experiments, considering DM interactions with target nuclei or electrons. We find that the presence of the LMC causes a considerable shift in the expected direct detection exclusion limits towards smaller cross sections and DM masses, with the effect being more prominent for low mass DM. Hence, our study shows, for the first time, that the LMC's influence on the local DM distribution is significant even in fully cosmological MW analogues.

Citation

Smith-Orlik, A., Ronaghi, N., Bozorgnia, N., Cautun, M., Fattahi, A., Besla, G., …Peter, A. H. (2023). The impact of the Large Magellanic Cloud on dark matter direct detection signals. Journal of Cosmology and Astroparticle Physics, 2023(10), Article 070. https://doi.org/10.1088/1475-7516/2023/10/070

• Journal Article Type: Article
• Acceptance Date: Sep 30, 2023
• Online Publication Date: Oct 27, 2023
• Publication Date: Oct 1, 2023
• Deposit Date: Dec 19, 2023
• Publicly Available Date: Dec 19, 2023
• Journal: Journal of Cosmology and Astroparticle Physics
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 2023
• Issue: 10
• Article Number: 070
• DOI: https://doi.org/10.1088/1475-7516/2023/10/070
• Keywords: dark matter experiments, dark matter theory, hydrodynamical simulations, dark matter simulations
• Public URL: https://durham-repository.worktribe.com/output/1863176