报告题目：Monopole Baryogenesis with a small theta angle

报  告  人：Huangyu Xiao 肖煌煜 (University of Chicago)

报告时间：2025年2月27日15：00

报告地点：物理楼（附中南侧）W105

内容摘要：Monopoles are generally expected in Grand Unified Theories (GUTs) where they can catalyze baryon decay at an unsuppressed rate by the Callan-Rubakov effect. For the first time, we show this catalysis effect can generate the observed baryon asymmetry at GeV scale temperatures. We study the minimal SU(5) GUT model and demonstrate that monopoles-fermion scattering with a CP-violating theta-term leads to realistic baryogenesis even theta is as small as 10^-10, consistent with current experimental bounds. Our calculation also shows that to generate the observed baryon asymmetry, the abundance of the monopoles is below the current experiential bounds and becomes an interesting target to look for.

报告人简介：Huangyu Xiao received his PhD from the University of Washington in 2022, and is now an associate fellow at the Kavli Institute of Cosmological Physics at the University of Chicago. He works on the intersection of particle physics, cosmology, and astrophysics. His major focus is on the particle nature of dark matter and how to look for it using astrophysical observations. He also works on various ideas on baryogenesis and gravitational waves.