{
  "id": 5587361,
  "title": "NA64, a decade of hunting dark matter",
  "url": "https://urgent.news/2026/09/04/na64-a-decade-of-hunting-dark-matter",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-04T14:57:00.000Z",
  "source": {
    "name": "CERN",
    "slug": "cern",
    "url": "https://home.cern/na64-a-decade-of-hunting-dark-matter/"
  },
  "original_language": "en",
  "account": "In September 2016, the NA64 experiment at CERN began its decade-long quest to detect dark matter by searching for missing energy when particles collide in its detector. Energy cannot be lost in particle physics; any shortfall indicates that an unseen particle has escaped detection. This concept led Wolfgang Pauli to propose the neutrino in 1930, a particle so elusive that it took quarter of a century to detect. The mysterious dark matter, comprising approximately 85% of the Universe's matter, does not emit light and can only be observed through its gravitational effects. For decades, the leading candidate for dark matter was a heavy particle roughly a hundred times more massive than the proton, but experiments have yet to find it. This absence of a signal could suggest that dark matter is lighter and interacts more weakly than initially thought. A particle of this nature could fit into a broader dark sector, consisting of new particles and forces that interact with known matter only through rare and feeble collisions. NA64 is situated in CERN's North Area, where 400 GeV protons from the Super Proton Synchrotron collide with a beryllium target, generating a variety of secondary particles. The appropriate beam is selected, guided to NA64, and each particle's energy is meticulously measured prior to impact. If the recorded energy post-interaction is less than the incoming particle's energy, the difference must have been absorbed by an undetectable particle, potentially a dark matter particle. For most of the experiment's duration, electrons were used as probes, but no missing energy beyond known processes was observed. However, these measurements have placed an upper limit on the coupling strength between the dark sector and ordinary matter, determining how frequently dark matter particles should be produced. This limit has been pushed further for some of the lightest candidates than any other experiment. The program has expanded beyond electrons, incorporating positrons (electrons' antimatter counterparts), muons (heavier counterparts), and hadrons to test various dark matter models. Since dark matter particles are produced infrequently, the next step is to increase collision frequency. During CERN's third long shutdown, NA64's apparatus will be upgraded to operate with more intense beams while minimizing the risk of unmeasured ordinary energy mimicking a signal. This enhanced dataset could grow by up to two orders of magnitude, enabling the testing of a wide range of scenarios for light dark matter.",
  "summary": "In particle physics, energy is never lost. When particles collide or decay, all the initial energy they carry must be conserved in the resulting products, and a shortfall signals that something has escaped unseen. It was the energy missing from radioactive decays that led Wolfgang Pauli to propose the neutrino in 1930, a particle so elusive that it evaded detection for […]",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}