What is Baryogenesis?

Baryogenesis is the scientific term for the generation of baryonic matter, which includes protons and neutrons, in the universe. According to the Big Bang theory, the universe began with equal amounts of matter and antimatter, which would have annihilated each other, leaving a universe devoid of baryonic matter. However, observations show that baryonic matter is the predominant type of matter in the universe. Therefore, baryogenesis seeks to explain how the universe ended up with more baryonic matter than antimatter.

Several theories and models have been proposed to explain baryogenesis. One popular theory is called Sakharov’s conditions, which postulates that three conditions must be met for baryogenesis to occur: baryon number violation, C and CP violation, and departure from thermal equilibrium. The baryon number violation allows for the creation of baryon-antibaryon pairs, the C and CP violation allows for asymmetry between matter and antimatter, and the departure from thermal equilibrium prevents the annihilation of matter and antimatter.

Theories and Models of Baryogenesis

Besides Sakharov’s conditions, other models of baryogenesis include electroweak baryogenesis, which involves the breaking of symmetry between the weak nuclear force and electromagnetism, and leptogenesis, which involves the decay of heavy neutrinos to create a matter-antimatter asymmetry. Some models of baryogenesis also involve the existence of new particles, such as the hypothetical X and Y bosons, which could lead to baryon number violation.

Experimental Evidence for Baryogenesis

The most significant evidence for baryogenesis comes from cosmic microwave background (CMB) radiation, which is the leftover radiation from the Big Bang. The CMB has a slight temperature variation across the sky, which indicates the distribution of matter in the universe. The latest observations from the Planck satellite show that the universe is composed of approximately 5% baryonic matter, 27% dark matter, and 68% dark energy. The ratio of baryonic matter to dark matter is consistent with the predictions of baryogenesis models.

Implications and Future of Baryogenesis Research

Baryogenesis research has several implications for our understanding of the universe, including the origin of matter and the nature of the early universe. Additionally, since baryogenesis involves the violation of fundamental symmetries and the creation of new particles, it has implications for particle physics and the search for new physics beyond the standard model. Future research on baryogenesis will involve more precise measurements of the CMB and the search for new particles and interactions that could explain the matter-antimatter asymmetry.