- The paper demonstrates a combined analysis that improves sensitivity to neutrino signals from WIMP annihilation across a mass range of 50–1000 GeV.
- It employs binned likelihood techniques and unified frameworks with NFW and Burkert profiles to set upper limits on the dark matter annihilation cross-section.
- The results constrain WIMP model parameters and lay the groundwork for future multi-detector collaborations in dark matter research.
Combined Search for Neutrinos from Dark Matter Annihilation in the Galactic Centre using ANTARES and IceCube
The paper presents a combined analysis of neutrino data collected by two prominent detectors—ANTARES and IceCube—aimed at probing dark matter (DM) annihilation in the Galactic Centre. This combined search is particularly focused on detecting neutrinos as secondary particles that are theorized to result from the self-annihilation of Weakly Interacting Massive Particles (WIMPs), a leading candidate for DM. The self-annihilation cross-section, denoted as ⟨σAυ⟩, is a crucial parameter in this investigation.
Methodology and Results
The research emphasizes unifying the analysis frameworks of ANTARES and IceCube, each of which previously delivered competitive, albeit limited, results over different segments of WIMP mass ranges. For WIMP masses exceeding 100 GeV, ANTARES provided more stringent limits, while IceCube achieved stronger results for lower masses. By leveraging a combined data set ranging from 50 to 1000 GeV, the paper successfully enhanced the sensitivity to the thermally averaged cross-section across this substantial mass window.
The methodology employed involved using binned likelihood techniques to integrate data from both sensors. The likelihood function is constructed by examining the Poisson probability of observed events contingent on the expected signal and background models, accounting for the relative efficiencies of the two telescopes. For signal PDFs, the paper favored the PPPC4 DM annihilation spectra for consistency between both detectors.
Two halo profiles were explored—the Navarro-Frenk-White (NFW) and the Burkert profile—to calculate the astrophysical J-factor, which quantifies the line-of-sight DM density integral over the region of interest. This analysis revealed no significant neutrino signal attributable to DM annihilation, thereby setting upper limits on ⟨σAυ⟩.
Numerical Insights and Observations
The paper delivered separate results for all channels of WIMP annihilation considered: W+W−, τ+τ−, μ+μ−, and bbˉ. Whereas results for the NFW profile showed consistent improvements over individual detector efforts, only the Burkert profile in the bbˉ channel was dominated by IceCube limits. This suggests that the combined analysis generally enhances detection sensitivity when data sets are unified.
Implications and Future Directions
While the paper successfully illustrates the advantages of combined analyses, it highlights areas for further research optimizations. The joint analysis provides a precedent for future collaborations which could extend to incorporate more extensive data sets or deploy an unbinned likelihood approach for enhanced statistical precision.
At a theoretical level, these limits further constrain the parameter space for WIMP models, informing cosmological simulations and indirect detection strategies. Practically, improved sensitivity in the combined analysis may guide the development of more comprehensive, possibly multi-modal, detection frameworks.
Looking forward, the integration of such neutrino observatories in coordinated DM campaigns could spark enhancements in both experimental setup and analytical technique. This research thereby contributes to a rigorous foundation for future interdisciplinary efforts in tackling the enigma of dark matter.