Physicists detect signals from the zeptoverse, smallest scale ever explored

Researchers have detected activity at the smallest scale of nature ever examined—100 billion times smaller than an atom—in a discovery that could reshape understanding of the Universe's fundamental workings. Scientists at the Large Hadron Collider (LHC) have observed interactions occurring at a scale of a billion-trillionth of a metre, a realm some physicists have termed the zeptoverse. According to BBC News, the findings emerged from an experiment led by Cambridge-based researchers and could help develop a more complete theory of how the Universe operates.

The experiment involved smashing atoms together at high energy at Cern, the European Laboratory for Particle Physics on the Swiss-French border, to break them apart and reveal their inner structure. Scientists then studied the debris from these collisions, focusing on a sub-atomic particle called a beauty quark. This particle is unstable, existing for only one and a half trillionths of a second before decaying into other forms. Despite its fleeting existence, researchers managed to observe it interacting with other tiny particles at unprecedented scales.

Why does detecting activity in the zeptoverse matter?

Dark matter comprises a substantial portion of the cosmos, yet scientists have struggled to detect it directly. Researchers know it exists because its gravitational force influences ordinary matter, but it remains invisible in all other respects. Theoretical physicists propose that at the scales explored in this experiment, particles become more sensitive to dark matter's influence and could reveal how quarks interact and decay. Observing activity in this minuscule realm could therefore provide a pathway to detecting dark matter itself.

The discovery builds on earlier work in the field. Previous research from underground laboratories has identified potential dark matter signals, though those findings remain unconfirmed with low statistical significance. The current LHCb results represent a complementary approach, using high-energy collisions rather than direct detection methods.

Dr Harry Cliff of Cambridge University, who led the analysis of the data, expressed the significance of the breakthrough.

We're knocking on the door of this zeptoverse,

he told BBC News, describing how the sub-atomic interactions provided researchers with a front-row view of the behaviour of potential new particles.

And what we want to do now is go in and explore and find what new particles are waiting there. And to do that, what we need is more data,

Cliff added.

What is the next step for this research?

The 28 countries participating in the project have approved a £150 million upgrade to the LHCb detector at the Large Hadron Collider, which would increase the frequency of these decay observations tenfold.

With that we can probe inside the zeptoverse and see what's waiting,

Cliff said. Recent LHCb analyses have already yielded intriguing results: researchers reported a four-standard-deviation discrepancy in a rare B-meson decay measurement compared to Standard Model predictions, though this falls short of the five-sigma threshold required for a formal discovery. Additionally, LHCb announced the observation of a new beauty-strange particle with a significance exceeding seven standard deviations, suggesting the detector continues to reveal unexpected phenomena.

The analysis examined approximately 650 billion B-meson decays recorded between 2011 and 2018, with the particular penguin decay occurring roughly once per million B mesons under Standard Model predictions. The newly discovered particle, designated as a potential chiral partner or exotic hadron, may represent either a long-sought theoretical object or an entirely unexpected form of matter.

How will UK funding cuts affect this research?

The research programme faces significant uncertainty following a decision by the UK Research and Innovation (UKRI) agency to withdraw its funding contribution for the planned upgrade. The government body announced the withdrawal as part of broader cuts to particle physics and astronomy projects, including reductions affecting Jodrell Bank's historic Lovell telescope. Prof Tim Gershon, who leads the LHCb international collaboration, warned that the UK's full participation in the research would be jeopardised by these cuts.

The UK is at risk of not being involved and making really major discoveries,

Gershon told BBC News. He emphasised that the long-term consequences extended beyond immediate scientific impact.

But I think the biggest long-term impact comes from the fact that the UK won't get the benefits from training young people who really are our greatest product.

The funding reductions are already affecting early-career researchers involved in the discovery. Dr Mary Richardson-Slipper, part of the team that detected the zeptoverse signals, is reconsidering her future in physics research within the UK.

I love being here in the UK, but I am looking at jobs abroad because that seems to be where there are more opportunities at the moment,

Richardson-Slipper said. She noted that numerous colleagues working in fundamental physics have already relocated internationally.

The cuts come despite an overall record increase in the science budget, raising questions about research funding priorities. The UK's particle physics community has faced mounting pressure as funding decisions have shifted emphasis away from fundamental research, even as the nation celebrates past achievements in the field.

What do prominent scientists say about the funding decision?

Prof Brian Cox, television presenter and particle researcher at the University of Manchester who was not part of the research team, described the zeptoverse discovery as

important

but strongly criticised the recent funding cuts.

It would be extraordinary to walk away from UK scientific leadership at this moment, damaging the future research programme and seriously damaging our hard-won international reputation,

Cox said.

In response, UKRI stated that it remained a fully engaged member of Cern as the organisation's second largest funder, providing approximately £175 million annually. A UKRI spokesperson explained:

We sought independent advice and have taken forward an exciting portfolio of new infrastructure investments, which include projects in clean energy, medical imaging and cultural heritage. However, as usual, there were more exciting applications for funding than we were able to support.

What happens next in the search for new physics?

The path forward depends on whether funding can be secured for the LHCb upgrade and whether the intriguing signals detected so far strengthen or fade with additional data. More LHC data and improved theoretical calculations are expected to test whether the four-sigma discrepancy observed in recent analyses strengthens into a formal discovery or diminishes over the coming years. The LHCb Upgrade II is planned for the later high-luminosity phase, with Run 5 scheduled for 2036 following the upgrade, providing a timeline for when researchers could probe deeper into the zeptoverse with substantially increased collision data.