Physics Colloquium: The Mystery of the Matter in the Universe

Kaori Fuyuto, Los Alamos National Laboratory

When

3 to 4 p.m., Dec. 3, 2021

Abstract: Why do we exist? Most of us must have wondered at least once. Answering it scientifically is one of the most serious and engrossing challenges in modern physics. The question translated into the language of particle and nuclear physics is: why is there more matter than antimatter in our Universe? Antimatter is composed of antiparticles which have opposite charges to those of their corresponding particles. In the early Universe, both matter and antimatter should have been present in equal amounts. However, looking around the present Universe, everything, such as galaxies, stars, our planet and ourselves, is made solely of matter. This puzzle is known as matter-antimatter asymmetry of the Universe. In this talk, I will discuss theoretical approaches to solving the mystery in terms of particle and nuclear physics introducing one possible hypothesis, electroweak baryogenesis, which is the most testable scenario in experiments today.