Search for dark matter towards the Galactic Centre with 11 years of ANTARES data

Abstract: Neutrino detectors participate in the indirect search for the fundamental constituents of dark matter (DM) in form of weakly interacting massive particles (WIMPs). In WIMP scenarios, candidate DM particles can pair-annihilate into Standard Model products, yielding considerable fluxes of high-energy neutrinos. A detector like ANTARES, located in the Northern Hemisphere, is able to perform a competitive search looking towards the Galactic Centre, where a high density of dark matter is thought to accumulate. Both this directional information and the spectral features of annihilating DM pairs are entered into an unbinned likelihood method to scan the data set in search for DM-like signals in ANTARES data. Results obtained upon unblinding 11 years of data are presented. A non-observation of dark matter is converted into limits on the velocity-averaged cross section for WIMP pair annihilation.

• The paper presents an analysis of 3170 days of ANTARES data to detect neutrinos from WIMP annihilation near the Galactic Centre.
• It employs directional and spectral analysis with an unbinned likelihood method, establishing upper limits on dark matter interaction cross sections.
• The study refines dark matter models and underscores the potential of next-generation observatories like KM3NeT for future breakthroughs.

Search for Dark Matter towards the Galactic Centre with 11 Years of ANTARES Data

The detection and analysis of weakly interacting massive particles (WIMPs) as constituents of dark matter (DM) are central themes in contemporary astrophysics. The study under examination presents an extensive analysis using the ANTARES neutrino telescope aimed at detecting neutrinos produced by annihilations of WIMPs concentrated towards the Galactic Centre, a region with a high concentration of dark matter.

Methodology and Analysis

The research utilizes 3170 days of ANTARES data, applying both directional and spectral analysis techniques to search for DM signatures. The ANTARES detector, situated in the Mediterranean Sea, offers a unique vantage point for observing the Southern celestial hemisphere, including the Galactic Centre. The analysis leverages an unbinned likelihood method to isolate potential dark matter signals from astrophysical backgrounds.

The ANTARES telescope is optimized for detecting neutrinos from charged current interactions, which aligns with the objectives of searching for by-products of WIMP annihilation. By capturing muon neutrinos exclusively, the study exploits the directional information of arriving neutrinos to localize potential dark matter sources.

Results

The study presented upper limits on the velocity-averaged cross section for WIMP pair annihilation into various final states, such as $b\bar{b}$, $W^+W^-$, and $\nu\bar{\nu}$. No significant evidence above the expected background was observed, allowing the researchers to set constraints on the cross-section parameters for several channels.

The research provides insights into the thermally averaged cross section $\langle \sigma v \rangle$ necessary for WIMP pair annihilation, which is crucial in testing various dark matter models. Despite the non-observation of dark matter signals, these constraints contribute valuable data to the field of indirect dark matter searches.

Implications and Future Work

The results obtained reinforce the importance of multi-channel analysis and the need for continued observations with enhanced sensitivity. The constraints imposed by this study help refine existing dark matter models and provide a benchmark for future experiments.

The paper indirectly underscores the potential and need for next-generation neutrino observatories like KM3NeT, which promise larger volumes and advanced detection capabilities. As detector technology advances, more stringent molecular limits and potentially the detection of WIMP annihilation signatures may materialize.

Conclusion

This research contributes to the ongoing efforts to detect dark matter through indirect means. While the non-observation emphasizes current challenges, it also sets the stage for future empirical breakthroughs, particularly with forthcoming advancements in neutrino detection. The ANTARES data reinforces the complex but promising nature of neutrino telescopes in dark matter studies.