It’s one of the oldest problems in the universe: Since matter and antimatter annihilate each other on contact, and both forms of matter existed at the moment of Big Bang, why does a universe consist mainly of matter and not nothing at all? Where has all the antimatter gone?
“The fact that our universe today is dominated by matter remains one of the most puzzling and protracted mysteries of modern physics,” said Yanou Cui, professor of physics and astronomy at Riverside University of California in an opinion shared this week. “A subtle imbalance or asymmetry between matter and antimatter in the early universe is required to achieve the dominance of matter today, but cannot be realized within the known framework of fundamental physics.”
There are theories that could answer this question, but they are extremely difficult to test laboratory experiments. Now in a new paper appeared in the magazine on Thursday Physical Verification Lettersdr Cui and her co-author Zhong-Zhi Xianyu, assistant professor of physics at Tsinghua University, China, explain that they may have found a solution to use the Big Bang afterglow itself to conduct the experiment.
The theory Drs. Cui and Zhong-Zh wanted to explore is known as leptogenesis, a process involving the decay of particles that may have led to the asymmetry between matter and antimatter in the early universe. In other words, an asymmetry in certain types of elementary particles in the very earliest moments of the cosmos may have evolved over time and through further particle interactions into the asymmetry between matter and antimatter that defines the universe as we know it – and life – have made. possible.
“Leptogenesis is among the most compelling mechanisms that produce matter-antimatter asymmetry,” said Dr. Cui in a statement. “This is a new elementary particle, the right-handed neutrino.”
But, added Dr. Cui adds, producing a right-handed neutrino would require far more energy than can be produced in particle accelerators on Earth.
“Testing leptogenesis is all but impossible because the mass of the right-handed neutrino is typically many orders of magnitude beyond the range of the most energetic collider ever built, the Large Hadron Collider,” she said.
The realization of Dr. Cui and her co-authors thought that scientists might not need to build a more powerful particle accelerator because the very conditions they want to create in such an experiment already existed in some parts of the early universe. The Inflation Era, an epoch of exponential expansion of time and space itself, which lasted only fractions of a second after the Big Bang….
“Cosmic inflation provided a high-energy environment that enabled the production of heavy new particles and their interactions,” said Dr. cui “The inflationary universe behaved like a cosmological collider, except the energy was up to 10 billion times greater than that of a human-made collider.”
Furthermore, the results of these natural cosmological collider experiments can be preserved today in the spread of galaxiesand the cosmic microwave background, the Big Bang afterglow, from which astrophysicists have derived much of their current understanding of the evolution of the cosmos.
“Specifically, we show that essential conditions for asymmetry generation, including the interactions and masses of the right-handed neutrino, which is the key player here, can leave clear fingerprints in the statistics of the spatial distribution of galaxies or the cosmic microwave background can be accurately measured,” said dr Cui, although these measurements have yet to be taken, she added. “The astrophysical observations expected in the coming years can possibly detect such signals and unravel the cosmic origin of matter.”