Scientists probe particle interactions at the smallest scale yet

Scientists have detected particle interactions at a scale about 100 billion times smaller than an atom, a finding that could help researchers test ideas about dark matter and the fundamental workings of the Universe.

The result came from an experiment at the Large Hadron Collider, where particles are smashed together at high energies. Researchers studied the debris, including short-lived beauty quarks, which decay into other particles after about 1.5 trillionths of a second.

The Cambridge-led team observed the quarks interacting at a scale of a billion-trillionth of a metre. Some theories suggest dark matter could have a greater influence on particles at such tiny distances, but the experiment has not detected dark matter itself.

“We’re knocking on the door of this zeptoverse,” Dr Harry Cliff of Cambridge University, who led the analysis, told the BBC. He said more data would be needed to explore whether new particles might be found.

The result comes as the international collaboration plans a £150m upgrade to the LHCb detector, which would increase the frequency of the relevant particle decays tenfold. The UK Research and Innovation agency has withdrawn its share of funding for the upgrade as part of cuts to several particle physics and astronomy projects.

Prof Tim Gershon, who leads the LHCb collaboration, told the BBC that the UK’s full involvement in the research was in doubt. UKRI said it remained a fully engaged member of CERN and its second-largest funder, contributing about £175m a year. The agency said it had chosen other infrastructure projects after receiving more funding applications than it could support.