Soon after the Big Bang, the cosmos was composed of an equal quantity of matter and “antimatter” particles, which are identical to matter but have the opposite charges. The universe then began to chill as space grew. There are many matter-based galaxies and stars in the cosmos today. Where did antimatter disappear and how did matter come to rule the universe? The genesis of stuff in the cosmos continues to baffle scientists.
Scientists from the University of California, Riverside and Tsinghua University in China have now created a novel method for exploring the cosmic genesis of matter by using the “cosmological collider.” In order to produce extremely heavy subatomic fundamental particles that could reveal new physics, high-energy colliders like the Large Hadron Collider have been built. Theoretical explanations for dark matter and the genesis of matter, for example, can entail far heavier particles and require much more energy than a collider created by humans is able to provide. The early universe may have served as a super-collider, it turns out.
Cosmic inflation, a time when the universe expanded at an exponentially rising rate before the Big Bang, was described by Yanou Cui, an associate professor of physics and astronomy at UCR. The formation of heavy new particles as well as their interactions were made possible by the highly energetic environment created by cosmic inflation, according to Cui. The energy in the inflationary universe was up to 10 billion times greater than any collider created by humans, but it behaved exactly like one.
Cui claimed that the expansion of the cosmos stretched the microscopic structures created by intense events during inflation, creating regions of variable densities in an otherwise uniform universe. The large-scale structure of our universe, which is still visible as the distribution of galaxies throughout the sky, was then seeded by these microscopic formations. Cui stated that probing the cosmological collider’s influence on the universe as it exists now, including galaxies and the cosmic microwave background, may yield new information on subatomic particle physics.
Cui and Zhong-Zhi Xianyu, an assistant professor of physics at Tsinghua University, report in the journal Physical Review Letters that the puzzle of the origin of matter in the cosmos may be solved by using the cosmological collider’s physics and precision data for measuring the structure of our universe from upcoming experiments like SPHEREx and 21 cm line tomography. One of the most puzzling, old puzzles in modern physics, according to Cui, is why our current world is dominated by matter. “To obtain today’s matter dominance, a small imbalance or asymmetry between matter and antimatter in the early cosmos is required but cannot be realized within the known framework of fundamental physics.”
Leptogenesis, a well-known mechanism that explains the creation of the baryon — visible gas and stars — imbalance in our universe, is the hypothesis put out by Cui and Xianyu. Equal amounts of matter and antimatter would have annihilated one another into photon radiation at the beginning of the universe, leaving nothing behind. Since matter now outnumbers antimatter, asymmetry is necessary to account for the imbalance. Leptogenesis is one of the most convincing processes producing the matter-antimatter asymmetry, according to Cui. “It involves the right-handed neutrino, a new basic particle. However, it has long been believed that verifying leptogenesis is practically difficult because the right-handed neutrino’s mass is often several orders of magnitudes beyond the capability of the Large Hadron Collider, the collider with the highest energy ever built.
By decoding the intricate statistical characteristics of the spatial distribution of items in the cosmic structure that can be seen today, which are reminiscent of the microscopic physics during cosmic inflation, the new work suggests testing leptogenesis. The scientists contend that the development of the super-heavy right-handed neutrino during the inflationary epoch is made possible by the cosmological collider effect. The interactions and masses of the right-handed neutrino, which is the main player in this scenario, are just two examples of the conditions that we specifically show can leave distinct fingerprints in statistics of the spatial distribution of galaxies or cosmic microwave background and can be precisely measured, according to Cui. “Such signals may be detected and the genesis of matter in the cosmos may be revealed by astrophysical observations expected in the future years.”