Latest news with #antimatter
Gizmodo
5 days ago
- Science
- Gizmodo
Physicists Create First-Ever Antimatter Qubit, Making the Quantum World Even Weirder
Readers following our existential physics coverage may remember a recent breakthrough from CERN concerning matter's evil twin, antimatter. An outstanding mystery in physics is that our universe contains more matter than antimatter, contradicting most theoretical predictions. Scientists, therefore, understandably want to explain why and how this is the case. CERN announced yet another significant leap for studying antimatter—and this time, the achievement creeps into the realm of quantum computing. In a Nature paper published on July 23, CERN's Baryon Antibaryon Symmetry Experiment (BASE) collaboration announced the first-ever demonstration of an antimatter quantum bit, or qubit—the smallest unit of information for quantum computers. The qubit in question is an antiproton, a proton's antimatter counterpart, caught in a curious quantum swing—arcing back and forth between 'up' and 'down' spin states in perfect rhythm. The oscillation lasted for 50 seconds. The technical prowess that enabled this result represents a significant leap forward in our understanding of antimatter, the researchers claim. For the experiment, the team applied a technique called coherent quantum transition spectroscopy, which measures—with chilling precision—a particle's magnetic moment, or its behavior inside magnetic fields. First, the team brought in some antiprotons from CERN's antimatter factory, trapping the particles in an electromagnetic Penning trap—a superposition of magnetic fields. Next, they set up a second multi-trap inside the same magnet, extracting individual antiprotons to measure and tweak the particle's spin states in the process. Quantum states are fragile and easily disturbed by outside distractions. The wrong push can immediately send them spiraling down the drain toward decoherence—at which point the system loses the valuable information physicists hope to find. This fundamental limitation of quantum systems was a major concern for the BASE collaboration, who in 2017 used a similar setup to the new experiment to confirm that protons and antiprotons had practically identical magnetic moments. The team made substantial revisions to its technology, paying special attention to developing the mechanisms needed to suppress and eliminate decoherence. This hard work paid off; the antiproton performed a stable quantum swing for 50 seconds—a motion akin to how qubits exist in superpositions of states, which theoretically could allow them to store exponential loads of information. Additionally, it marked the first time physicists observed this phenomenon in a single free nuclear magnetic moment, whereas previous experiments had only seen it in large groups of particles. 'This represents the first antimatter qubit and opens up the prospect of applying the entire set of coherent spectroscopy methods to single matter and antimatter systems in precision experiments,' BASE spokesperson Stefan Ulmer said in a statement. That said, the team doesn't believe the new results will introduce antimatter qubits to quantum computing, at least not anytime soon. 'It does not make sense to use [the antimatter qubit] at the moment for quantum computers, because, simply speaking, engineering related to production and storage of antimatter is much more difficult than for normal matter,' Latacz explained, adding that since matter and antimatter are known to share fundamental properties, opting for the latter wouldn't make practical sense. 'However, if in the future [we find] that antimatter behaves differently than matter, then it may be interesting to consider this.' There are additional improvements the team hopes to make, which will happen sometime very soon, Latacz said. The upgrades to BASE—termed BASE-STEP—will greatly improve our capacity to study antiprotons with higher precision and allow us to 'improve the measurement of the magnetic moment of the antiproton by at least a factor of 10, and in a longer perspective even a factor of 100,' she said. The new breakthrough could contribute to engineering advances in quantum computing, atomic clocks, and other areas. But as the researchers emphasize, such technological applications aren't anything we should expect any time soon. Nevertheless, the result itself presents some fascinating lessons for fundamental physics—questions that may take years to answer, but to quote physicist Sean Carroll from the other recent CERN finding, 'Well, it's a small part of a much bigger puzzle—but you know, every part matters.'
The Independent
17-07-2025
- Science
- The Independent
Scientists make antimatter discovery that could unlock secrets of big bang
Why didn't the universe annihilate itself moments after the big bang? A new finding at Cern on the French-Swiss border brings us closer to answering this fundamental question about why matter dominates over its opposite – antimatter. Much of what we see in everyday life is made up of matter. But antimatter exists in much smaller quantities. Matter and antimatter are almost direct opposites. Matter particles have an antimatter counterpart that has the same mass, but the opposite electric charge. For example, the matter proton particle is partnered by the antimatter antiproton, while the matter electron is partnered by the antimatter positron. However, the symmetry in behaviour between matter and antimatter is not perfect. In a paper published this week in Nature, the team working on an experiment at Cern, called LHCb, has reported that it has discovered differences in the rate at which matter particles called baryons decay relative to the rate of their antimatter counterparts. In particle physics, decay refers to the process where unstable subatomic particles transform into two or more lighter, more stable particles. According to cosmological models, equal amounts of matter and antimatter were made in the big bang. If matter and antimatter particles come in contact, they annihilate one another, leaving behind pure energy. With this in mind, it's a wonder that the universe doesn't consist only of leftover energy from this annihilation process. However, astronomical observations show that there is now a negligible amount of antimatter in the universe compared to the amount of matter. We therefore know that matter and antimatter must behave differently, such that the antimatter has disappeared while the matter has not. Understanding what causes this difference in behaviour between matter and antimatter is a key unanswered question. While there are differences between matter and antimatter in our best theory of fundamental quantum physics, the standard model, these differences are far too small to explain where all the antimatter has gone. So we know there must be additional fundamental particles that we haven't found yet, or effects beyond those described in the standard model. These would give rise to large enough differences in the behaviour of matter and antimatter for our universe to exist in its current form. Revealing new particles Highly precise measurements of the differences between matter and antimatter are a key topic of research because they have the potential to be influenced by and reveal these new fundamental particles, helping us discover the physics that led to the universe we live in today. Differences between matter and antimatter have previously been observed in the behaviour of another type of particle, mesons, which are made of a quark and an antiquark. There are also hints of differences in how the matter and antimatter versions of a further type of particle, the neutrino, behave as they travel. The new measurement from LHCb has found differences between baryons and antibaryons, which are made of three quarks and three antiquarks respectively. Significantly, baryons make up most of the known matter in our universe, and this is the first time that we have observed differences between matter and antimatter in this group of particles. The LHCb experiment at the Large Hadron Collider is designed to make highly precise measurements of differences in the behaviour of matter and antimatter. The experiment is operated by an international collaboration of scientists, made up of over 1,800 people based in 24 countries. In order to achieve the new result, the LHCb team studied over 80,000 baryons ('lambda-b' baryons, which are made up of a beauty quark, an up quark and a down quark) and their antimatter counterparts. Crucially, we found that these baryons decay to specific subatomic particles (a proton, a kaon and two pions) slightly more frequently – 5 per cent more often – than the rate at which the same process happens with antiparticles. While small, this difference is statistically significant enough to be the first observation of differences in behaviour between baryon and antibaryon decays. To date, all measurements of matter-antimatter differences have been consistent with the small level present in the standard model. While the new measurement from LHCb is also in line with this theory, it is a major step forward. We have now seen differences in the behaviour of matter and antimatter in the group of particles that dominate the known matter of the universe. It's a potential step in the direction of understanding why that situation came to be after the big bang. With the current and forthcoming data runs of LHCb we will be able to study these differences forensically, and, we hope, tease out any sign of new fundamental particles that might be present.
ABC News
16-07-2025
- Science
- ABC News
Large Hadron Collider glimpses clue in search for universe's missing antimatter
Scientists have uncovered another clue in the effort to solve one of the great puzzles of modern physics: why there is more matter than antimatter in the universe. The discovery relied on observations made with the world's largest machine, the Large Hadron Collider, which helps researchers to probe the fundamental nature of matter. Everything we see around us is made up of subatomic matter particles such as protons and neutrons, which belong to a category of particles called baryons. An experiment using the giant particle accelerator, based at CERN in Switzerland, has for the first time seen baryons form more matter than antimatter. The findings could change our understanding of how small particles interact and help explain the absence of antimatter, said Tom Hadavizadeh, a physicist at Monash University and collaborator on the project. "We haven't found the new physics yet, but it's given us a new way to look for it," Dr Hadavizadeh said. The researchers have published their findings in Nature. The current leading theory in particle physics — the Standard Model — predicts that for every particle of matter that forms, a corresponding particle of antimatter forms. Antimatter particles are identical to matter particles, but with their electrical charges reversed. Scientists have observed similar amounts of matter and antimatter being generated when they create subatomic particles by colliding larger particles at high speed around large underground loops in the Large Hadron Collider. But antimatter doesn't tend to stick around — if it collides with regular matter, both particles annihilate each other, releasing energy. If antimatter and matter were truly created in equal amounts, as per the Standard Model, the universe wouldn't exist. The problem for this theory is that the universe does exist, and it's mostly made of matter, with only tiny amounts of antimatter. This "matter-antimatter asymmetry" is a major unresolved problem in physics. "The way that we explain that is that at some point in the early universe, matter should have become slightly favoured over antimatter," Dr Hadavizadeh said. "There's this little excess that remains once most of the antimatter and matter annihilates away, and that little excess is what we see left over today." So where did this asymmetry between matter and antimatter come from? Ray Volkas, a physicist at the University of Melbourne who wasn't involved in the research, said that the Standard Model does have a way of explaining some of the matter-antimatter asymmetry. "It's been known since the early 1960s experimentally that there actually is a subtle difference in the way that matter and antimatter interact [with other particles]," Professor Volkas said. This subtle difference is called the charge-parity violation, or CP violation, and can help explain why there is less antimatter than matter. While researchers had observed this asymmetry in some smaller particles, they had not yet observed it in baryons — a type of subatomic particle made from three quarks. "Almost all of the matter that we come across is baryons," Dr Hadavizadeh said. The team of more than 1,500 scientists from 20 countries, called the 'Large Hadron Collider beauty' (LHCb) collaboration, used the giant particle accelerator to look for examples of asymmetry in baryons. They analysed libraries of data from the first few years of the experiment, looking specifically at curiously named "beauty" baryons. They were able to spot baryons decaying in an asymmetric way — generating more matter than antimatter. Professor Volkas says it is an "interesting result" but neither he, nor the LHCb researchers, think they've come close to solving the whole matter-antimatter mystery yet. "The amount of CP violation in the Standard Model is actually not sufficient to explain cosmological matter-antimatter asymmetry," Professor Volkas said. "It's one of the great mysteries of science." Matter-antimatter asymmetry is just one problem with the Standard Model. While it's beaten all the tests particle physicists have set for it over the decades, the theory has huge gaps in it. It also can't explain gravity or dark energy, a mysterious phenomenon thought to be behind the acceleration of universe expansion. "We don't want our theories to be totally wrong — in fact, they can't be because they work too well — but we want them to be incomplete so that we can add things," Professor Volkas said. He says the LHCb experiment, and similar ones, are getting increasingly thorough at scrutinising the matter-antimatter mystery. "What they're trying to do is examine this CP violation effect with ever greater precision to try to find if the standard theory continues to be verified, or if it will fail and we'll need to extend or modify the theory." While this new result is consistent with the Standard Model, the researchers suggest it might point towards places where they can move beyond the theory. Now that the researchers have measured the asymmetry in baryons, they'll be able to investigate this phenomenon more closely. The study potentially "unlocks a whole new set of particles" to observe new types of physics, Dr Hadavizadeh said.
Gizmodo
16-07-2025
- Science
- Gizmodo
CERN Physicists Find Key Piece of the Matter-Antimatter Puzzle
All matter in our universe has an evil twin: antimatter. Cosmological models suggest that the Big Bang should have created equal amounts of matter and antimatter that cancel each other out. But for reasons physicists still aren't completely sure about, that didn't happen. As a result, our universe today hosts slightly more matter than antimatter—our very existence being clear, physical proof. Now, we might be one step closer to explaining why there's an imbalance between matter and antimatter, an unsolved mystery in physics formally known as the charge-parity (CP) violation, or CP asymmetry. In a paper published today in Nature, researchers at the Large Hadron Collider beauty (LHCb) Collaboration at CERN, Switzerland, report the first experimental verification of the CP violation in the decay of baryons—fundamental particles that make up most matter in the observable universe. The results were announced earlier this year at the Rencontres de Moriond conference. 'Until recently, CP violation had only been clearly observed in mesons [or] particles made of a quark and an antiquark,' explained Xueting Yang, LHC physicist and study lead author, in an email to Gizmodo. 'This result shows that baryons—which are made of three quarks like protons and neutrons—can also violate CP symmetry.' While a significant first step, the new finding still falls short of observing baryon asymmetry, which refers to that paradox of there being more matter than antimatter in the universe today. What Yang's team observed specifically was an instance of CP violation in baryon decay, or the slight difference in behavior between a baryon and its antimatter counterpart as the particle breaks down into smaller particles. 'Well, it's a small part of a much bigger puzzle—but you know, every part matters,' Sean Carroll, a theoretical physicist at Johns Hopkins University who wasn't involved in the new work, told Gizmodo in a video call. 'It's intrinsically interesting when you find a phenomenon that has never been observed before, but…maybe it will teach us something about why there are more baryons than anti-baryons in the universe.' For the study, Yang's team took around nine years of data from observing the decay of almost one trillion beauty-lambda (Λb) baryons, the heavyweight cousin-particle of protons and neutrons. In about a mere trillionth of a second, beauty-lambda baryons and their antimatter counterparts break down into smaller parts, requiring the technical prowess of something as big as the LHC to capture. From the data, the researchers sifted through the different interactions to pick out the ones of interest to them, namely the decay behavior of beauty-lambda baryons and their antimatter counterparts. 'If CP symmetry were true, you'd have exactly the same rate for these interactions,' Carroll explained. 'But it is violated, so you get slightly different rates.' That rate was about 2.5%, a small but statistically significant difference—at least, enough for the team to start brainstorming ideas for how they'd like to build on this result. 'Studying how baryons are formed, how they interact, and how they decay is essential to understanding the fundamental forces of nature,' Yang said. 'This observation marks just the beginning. To answer why [the universe contains] more matter than antimatter, we need more sources of CP violation than the current [Standard Model of particle physics].' The Standard Model—the theory that describes particle behavior with chilling accuracy—is both the magnum opus and the punching bag of particle physics. It explains everything so ludicrously well, while missing some huge chunks of known physical phenomena, such as gravity or dark matter, to name a few. And so, when the LHC came along, physicists expected it to achieve great things—which it did, and continues to do. But as with all great physics discoveries, it's a holy grail that'll take some more time to realize. 'We were, to be honest, a little bit disappointed that the Large Hadron Collider hasn't found any physics beyond the Standard Model,' Carroll said. 'But I think it's super important to keep looking. The LHC is a beautiful machine that has done amazing work—and yet, it hasn't quite taken us to the promised land. So it's another reminder that there are really big questions out there, and one way or the other we, as the human race, should be doing our best to answer them.'
New York Times
16-07-2025
- Science
- New York Times
New Clue to How Matter Outlasted Antimatter at the Big Bang Is Found
Understanding why matter and antimatter behave differently is key to understanding why there is a universe at all. Now physicists have discovered the latest example of a subtle difference between the stuff that makes up galaxies, stars, planets and us, and its evil-twin opposite. Particles of antimatter, like anti-electrons and anti-protons, possess the same mass but opposite electric charge as the usual electrons and protons. In a discovery published on Wednesday in the journal Nature, an international collaboration of scientists working at the CERN particle physics laboratory outside Geneva described an imbalance among particles that are cousins to the protons and neutrons that make up everyday objects. That makes the new observations 'very important for us to further understand bigger questions like the matter-antimatter asymmetries in the universe,' said Xueting Yang, a graduate student at Peking University who led the analysis. The Big Bang that created the universe should have produced equal amounts of matter and antimatter. When a particle of matter bumps into its antimatter counterpart, the two particles annihilate. Thus, all of the matter should have annihilated all of the antimatter in a cataclysmic burst of radiation, leaving an empty universe for eternity. And yet, 13.8 billion years later, you — made of matter, not antimatter — are reading this news on a device (or in a newspaper), which is also made of matter. Somehow, in the instant after the Big Bang, for each billion or so pairs of matter and antimatter, an extra particle of matter persisted. This slight tipping of the laws of physics toward matter is known as charge-parity, or CP, violation. Want all of The Times? Subscribe.
