师晓东，日本高能加速器研究机构(KEK)博士后。2016年本科毕业于中国科学技术大学。2021年博士毕业于中国科学技术大学。博士后工作于日本KEK。研究生期间的工作主要涉及到北京正负电子对撞机上的北京谱仪III实验的数据分析、超级陶粲正负电子对撞机的预研工作。在博士后期间，他参与了位于日本筑波市的第二代B介子工厂Belle II实验，研究涉及到Belle II实验上中心漂移室上的束流本底测量、角的精确测量。

报告摘要：

CP violation is quite essential to understand the matter-antimatter asymmetry of our universe. In the Standard Model, the only CP violation source in quark sector is one complex phase of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. One important and interesting topic of flavor physics is to examine this CKM matrix. A clear way is to check the unitary of the CKM matrix by checking the triangle. One angle of the triangle,  or called as , can be measured through the interference in  decay. In this seminar, we will talk about all  results from Belle and Belle II. Furthermore, we will show the prospect of  at Belle II.