The Dark Matters at ICRC 2025

TL;DR

ICRC 2025 portrays dark matter research as a mature, multimessenger enterprise spanning ~80 contributions across ~90 mass scales. The study emphasizes four shifts: direct detection contending with the neutrino floor via CE$ u$NS, indirect searches adopting joint multi-instrument likelihoods across messengers, the rise of non-WIMP candidates (axions, sub-GeV states, PBHs, macroscopic relics), and a convergence of neutrino, gamma-ray, and direct-detection communities through shared data infrastructures. Key findings include CE$ u$NS indications in Xe-based detectors, first comprehensive dwarf-galaxy joint analyses, and robust multimessenger constraints on a broad DM landscape, including ALPs and macroscopic objects. The work argues that near-term progress hinges on coordinated analyses and open data frameworks as much as on new detectors, guiding the field toward reproducible, cross-instrument discovery potential. Overall, the report frames dark matter as a broad, integrated program where structural collaboration and methodological coherence are as essential as experimental reach for future breakthroughs.

Abstract

The dark matter track at ICRC~2025 showed a field in transition. Direct detection has entered the \emph{neutrino-floor era}, with XENONnT and PandaX-4T now limited by Solar neutrinos. Indirect searches have become truly \emph{multimessenger}, combining $γ$-rays, neutrinos, cosmic rays, and radio data under unified likelihoods and shared systematics. Non-WIMP candidates -- axions, sub-GeV particles, primordial black holes, macroscopic relics -- are becoming central. Across all fronts, progress depends as much on new detectors as on the coherence of shared data, methods, and analysis frameworks. Here, I distill the main experimental and conceptual shifts behind these trends, noting how assumptions have evolved since ICRC~2023 and where the next decisive advances are likely to come.

Figures (9)

• Figure 1: Distribution of dark matter ICRC 2025 contributions by dark matter particle mass. The bar height represents the number of contributions (left $y$-axis), with the corresponding percentage of total contributions shown on the right $y$-axis. Filled segments indicate talks and dashed segments represent posters.
• Figure 2: Four decades of progress in spin-independent WIMP searches. Markers show the spin–independent WIMP–nucleon limits from HPGe crystals, cryogenic bolometers, bubble chambers, liquid argon, and liquid xenon experiments for $m_\chi = 50$ GeV. The dashed line marks the onset of the neutrino fog ($\sim$1 expected CE$\nu$NS event for multi-ton-year exposures). The two faint gray bands highlight the overall improvement of about eight orders of magnitude in sensitivity---from early HPGe/bolometer results to current liquid–xenon limits. Adapted from Baudis:2025.
• Figure 3: Observation of solar $^8$B neutrinos via CE$\nu$NS in XENONnT. Left: projected distributions of best-fit signal and background components combining both science runs (SR0 and SR1). Data points (black) are shown with Poisson error bars; the CE$\nu$NS signal (green) is stacked above accidental coincidences (purple), electronic recoils (blue), and neutrons (yellow). Right: upper panel—68% (90%) measurement of solar $^8$B neutrino flux compared with SNO, XENON1T, and PandaX-4T (2023, see updated results in PandaX4T:2025); lower panel—flux-weighted CE$\nu$NS cross-section measured with XENONnT, alongside COHERENT results using different targets. Adapted from XENONnT:2025.
• Figure 4: Complementary sensitivity of neutrino detectors to dark matter. Left: IceCube 90% C.L. sensitivity to cosmic-ray upscattered sub-GeV dark matter for pseudoscalar mediators, showing complementarity with Super-Kamiokande Cavicchi:2025. Right: Projected RES-NOVA sensitivity to spin-independent DM-nucleon scattering, compared with direct detection and neutrino limits Iachellini:2025.
• Figure 5: $\gamma$-ray coverage of current and upcoming observatories presented at ICRC 2025. Present instruments (blue) and planned facilities (magenta) together provide continuous sensitivity from tens of MeV to multi-PeV energies. Notably, no next-generation space-based $\gamma$-ray mission from ESA or NASA is currently planned to succeed Fermi, now operating beyond its expected lifetime, likely leaving a gap in MeV–GeV coverage in the coming decade.