By The Hebrew University of Jerusalem November 27, 2025
Collected at: https://scitechdaily.com/a-chilling-experiment-near-absolute-zero-finds-hints-of-dark-matter/
Physicists using near-absolute-zero detectors have reached unprecedented sensitivity in the hunt for light dark matter.
A groundbreaking scientific project known as QROCODILE, led by the University of Zurich and the Hebrew University of Jerusalem, has reached unprecedented sensitivity in the search for light dark matter. By using superconducting detectors cooled to temperatures near absolute zero, the research team has established world-leading constraints on how dark matter might interact with regular matter, opening new possibilities for discoveries in one of physics’ most enduring puzzles.
Dark matter, the mysterious material thought to make up about 85% of the universe’s total mass, continues to baffle scientists. It does not emit or absorb light and cannot be detected directly, leaving researchers to infer its existence through its gravitational effects on galaxies and cosmic structures. Despite decades of experiments, no one has yet observed dark matter particles directly.
An international team of physicists is now reporting encouraging early results from the QROCODILE experiment (Quantum Resolution-Optimized Cryogenic Observatory for Dark matter Incident at Low Energy). This collaboration, led by the University of Zurich and the Hebrew University of Jerusalem and including Cornell University, the Karlsruhe Institute of Technology (KIT), and MIT, has demonstrated a powerful new approach to exploring the possible existence of “light” dark matter particles.
Ultra-Sensitive Superconducting Detection
At the heart of QROCODILE is a cutting-edge superconducting detector capable of measuring incredibly faint energy deposits — down to just 0.11 electron-volts, millions of times smaller than the energies usually detected in particle physics experiments. This sensitivity opens an entirely new frontier: testing the existence of extremely light dark matter particles, with masses thousands of times smaller than those probed by previous experiments.
In a science run lasting more than 400 hours at temperatures near absolute zero, the team recorded a small number of unexplained signals. While these events cannot yet be confirmed as dark matter — they may stem from cosmic rays or natural background radiation — they already allow researchers to set new world-leading limits on how light dark matter particles interact with electrons and atomic nuclei
An additional strength of the experiment is its potential to detect the directionality of incoming signals. Since the Earth moves through the galactic halo, dark matter particles are expected to arrive from a preferred direction. Future upgrades could allow scientists to distinguish between true dark matter signals and random background noise, a crucial step toward a definitive discovery.
Prof. Yonit Hochberg of the Racah Institute of Physics at the Hebrew University, one of the project’s lead scientists, explains: “For the first time, we’ve placed new constraints on the existence of especially light dark matter. This is an important first step toward larger experiments that could ultimately achieve the long-sought direct detection.”
The next stage of the project, NILE QROCODILE, will further enhance the detector’s sensitivity and move the experiment underground to shield it from cosmic rays. With improved shielding, larger detector arrays, and even lower energy thresholds, the researchers aim to push the boundaries of our understanding of the dark universe.
Reference: “First Sub-MeV Dark Matter Search with the QROCODILE Experiment Using Superconducting Nanowire Single-Photon Detectors” by Laura Baudis, Alexander Bismark, Noah Brugger, Chiara Capelli, Ilya Charaev, Jose Cuenca García, Guy Daniel Hadas, Yonit Hochberg, Judith K. Hohmann, Alexander Kavner, Christian Koos, Artem Kuzmin, Benjamin V. Lehmann, Severin Nägeli, Titus Neupert, Bjoern Penning, Diego Ramírez García and Andreas Schilling, 20 August 2025, Physical Review Letters.