Step inside the zeptoverse: British scientists use the Large Hadron Collider to peer inside a minuscule world where exotic particles may be hiding

British scientists have used the Large Hadron Collider to peer inside the minuscule world of the zeptoverse.The zeptoverse exists at the smallest scales ever explored by science, where objects are as small as a single zeptometre – or one trillionth of a billionth of a metre.The Large Hadron Collider can measure reality down to 100 zeptometres – about a billion times smaller than an atom – but scientists think there could be particles hiding at even smaller scales. Now, after a 42–year search, researchers finally observed a one–in–10–billion event that could reveal the zeptoverse's exotic particles. The team captured the moment an ultra–rare particle called a beauty quark decayed into two even smaller particles called muons.This transformation, known as the Bd to mu mu decay, is one of the rarest events imaginable and could be the key to understanding the zeptoverse.Dr Harry Cliff, who led the analysis team at the University of Cambridge's Cavendish Laboratory, says: 'Seeing clear evidence for this rarest decay for the first time was thrilling.'Physicists have been looking for this rare type of decay since 1984, which was before I was born.'British scientists have used the Large Hadron Collider (pictured) to peer inside the minuscule zeptoverse, a world of tiny particles that exist at scales 100 billion times smaller than an atom. Pictured: A visualisation of a beauty particle decaying into two muonsBeauty quarks are exotic cousins of the up and down quarks that make up all of the atomic matter in the universe.These tiny pieces of matter are the basic building blocks of larger particles called hadrons, which include protons and neutrons.These strange particles don't normally exist in nature, but can be created in huge quantities when the Large Hadron Collider smashes protons together at nearly the speed of light.They only exist for less than two trillionths of a second before decaying, and only one in 10 billion undergoes the Bd to mu mu decay, making it nearly impossible to observe.However, that rarity is exactly what makes this specific type of decay so interesting to particle physicists.In general, the rarer a decay is, the more sensitive it is to the influence of new particles which 'pop out of the vacuum' to interfere.For a beauty quark to decay into two muons, it must go through an astonishingly complicated set of reactions, but new particles in the zeptoverse could provide an additional route for the decay to follow, altering how often it occurs.By looking at tiny variations in these decay events, researchers may be able to study those impossibly tiny zeptometre–sized particles by their subtle influence on the Bd to mu mu decay.Scientists discovered a one–in–10–billion event in which a rare particle called a beauty quark decays into two even smaller particles called muons. Pictured: a simulation of a beauty quark experiment Scientists combed through ten years of data from the Large Hadron Collider beauty (LHCb) experiment to find this incredibly rare decay event because they believe it could help them study even smaller particles in the zeptoverse Dr Cliff says: 'We're knocking on the door of the zeptoverse now. I can't wait to see what we find as we explore deeper.'This new research, to be presented at CERN today, is the first time that this rare type of decay has ever been observed in a single experiment.To find it, researchers combed through 10 years of collision data from the Large Hadron Collider beauty (LHCb) experiment.Thanks to a major upgrade in 2024, scientists were able to tell the different types of particles apart and used machine learning to search for an instance of the decay, eventually finding about a dozen potential candidates.According to the researchers, this evidence has now been classified as '3.2 sigma' - a level of statistical significance that denotes a 'significant' finding but falls short of the 'five sigma' level needed to declare a new discovery.However, when the LHC's successor, the Future Circular Collider, comes online around 2045, scientists will know exactly what they need to look for.The LHC itself is also due for a major upgrade by the mid–2030s that would increase the collection rate by an order of magnitude, potentially revealing further details about the zeptoverse.Professor Brian Cox, the broadcaster and University of Manchester particle physicist, who was not involved with the experiment, says: 'This is an important result and a beautiful example of how science advances. We upgrade our instruments, and we see nature in greater detail. Professor Brian Cox (pictured) described this as an 'important result and a beautiful example of how science advances These results will help future scientists hunt for particles in the zeptoverse when the Future Circular Collider comes online around 2045 'We cannot know whether this progress will be incremental or genuinely world–changing – that's science! LHCb is a major scientific success.'These findings are also being hailed as a major success for British science, with the research team being led by academics from the Universities of Cambridge and Manchester.Professor Chris Parkes, who led the LHCb international collaboration from the University of Manchester, says: 'The UK made the largest national contribution to the project, pioneering new technologies that have made today's result possible, where we probe nature at a new scale.'But this is also just the start, we are planning the construction of an experiment that will exploit the capabilities of the next–generation High Luminosity LHC, probing physics at an even smaller scale.'Likewise, Dr Stefano De Capua, who led the construction of the detectors at the University of Manchester, added: 'We worked with nearly 90 UK companies to construct this detector and trained the next generation of scientists and engineers on the novel technologies we are using.'However, this comes at a time when the future role of Britain in international scientific collaborations has come into question.The 28 countries involved in the LHCb have agreed on a £150million upgrade, but the UK Research and Innovation (UKRI) agency announced last year that it was withdrawing its share of the funding.UKRI then announced it would be cutting funding to several other particle physics and astronomy projects, including the legendary Lovell Telescope at Jodrell Bank.While the UK remains a member of the CERN collaboration, this has put British scientists' role in future ground–breaking discoveries in doubt.WHAT IS THE LARGE HADRON COLLIDER?The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator.It is located in a 27-kilometer (16.8-mile) tunnel beneath the Swiss-French border.The LHC started colliding particles in 2010. Inside the 27-km LHC ring, bunches of protons travel at almost the speed of light and collide at four interaction points. Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes.They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets. The LHC (pictured) was restarted on April 5th 2015, having been turned off for two years during a major renovation project that cost £100 million The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy.These collisions generate new particles, which are measured by detectors surrounding the interaction points. A view of the LHC's Compact Muon Solenoid experiment is shownBy analysing these collisions, physicists from all over the world are deepening our understanding of the laws of nature.While the LHC is able to produce up to 1 billion proton-proton collisions per second, the HL-LHC will increase this number, referred to by physicists as 'luminosity', by a factor of between five and seven, allowing about 10 times more data to be accumulated between 2026 and 2036. This means that physicists will be able to investigate rare phenomena and make more accurate measurements. For example, the LHC allowed physicists to unearth the Higgs boson in 2012, thereby making great progress in understanding how particles acquire their mass. The subatomic particle had long been theorised but wasn't confirmed until 2013.