One of the oldest problems in the universe: To be important and antimatter they annihilate each other in contact, and both forms of matter existed at the time of the event. big BangWhy is there a universe composed primarily of matter and not of nothing? Where did all the antimatter go?
“The fact that our present-day universe is governed by matter remains one of the most puzzling, long-standing mysteries in modern physics,” said Yanou Cui, Riverside professor of physics and astronomy. Said. in a statement shared this week. “A subtle imbalance or asymmetry between matter and antimatter is required in the early universe to achieve today’s dominance of matter, but it cannot be realized within the framework of known fundamental physics.”
There are theories that could answer this question, but they are extremely difficult to test using them. lab experiments. Now a new paper Published in the magazine on Thursday Physical Review LettersDr Cui and his co-author, Zhong-Zhi Xianyu, an assistant professor of physics at Tsinghua University in China, explain that they may have found a study using the afterglow of the big bang to run the experiment.
The theory that Drs Cui and Zhong-Zh want to explore is known as leptogenesis, a process involving particle decay that could lead to asymmetry between matter and antimatter in the early universe. In other words, an asymmetry in some types of elementary particles in the earliest moments of the cosmos could have evolved over time and through further particle interactions into the asymmetry between matter and antimatter that makes the universe as we know it – and life – possible.
Dr. “Leptogenesis is one of the most compelling mechanisms that creates the matter-antimatter asymmetry,” Cui said in a statement. “It contains a new fundamental particle, the right-handed neutrino.”
But Dr Cui added that producing a right-handed neutrino would require much more energy than could be produced in particle colliders on Earth.
“Testing leptogenesis is nearly impossible because the right-handed neutrino mass is typically many orders of magnitude beyond the reach of the Large Hadron Collider, the highest-energy collider ever built,” he said.
Dr Cui and his co-authors’ view was that scientists might not need to build a more powerful particle collider because the conditions they wanted to create in such an experiment already existed in parts of the early universe. The inflationary period, which lasted only fractions of a second after the big bang, was the era of exponential expansion of time and space itself.
“Cosmic inflation provided a highly energetic environment, enabling the production of heavy new particles and their interactions,” said Dr Cui. “The inflationary universe acted just like a cosmological collider, except the energy was 10 billion times greater than any man-made collider.”
Also, the results of these natural cosmological collider experiments can be preserved in their current distribution. galaxiesThe cosmic microwave background, as well as the afterglow of the big bang, from which astrophysicists derive much of their current understanding of the evolution of the cosmos.
“In particular, we show here that the conditions necessary for the generation of asymmetry, including the interactions and masses of right-handed neutrinos, which are the key players, can leave distinctive fingerprints in the statistics of the spatial distribution of galaxies or the cosmic microwave background that can be measured with precision,” he said. The observations could potentially detect such signals and unravel the cosmic origin of matter.”
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