Spacetime and Spin Symmetries in Scattering Amplitudes

by Jiang-Hao Yu (ITP, CAS)

Wednesday 9 Apr 2025, 15:00 → 17:00 Asia/Shanghai

摘要：The on-shell scattering amplitudes make the spacetime symmetry explicitly manifest, leading to both efficient calculation to simplify tree/loop results, and consistent condition to dictate interactions uniquely. We explore an extended Poincare symmetry of scattering amplitudes based on spontaneous breaking of SO(5,1), which introduces chirality quantum number and chirality flip in massive scattering amplitudes, and determines the 3-point massive amplitudes completely. Using the chirality/helicity flip, a large energy effective theory is introduced to perform mass expansion (m/E) around the massless UV amplitudes systematically, building up massless-massive correspondence and explaining the on-shell Higgsing and Goldstone equivalence theorem. To further investigate the unitarity/resonance behavior, the spin symmetry is identified to perform the on-shell partial wave analysis based on covariant spin-orbital decomposition, which provides a new understanding of quantum entanglements from on-shell amplitude point of view.

个人简介：

于江浩，中国科学院理论物理研究所研究员，中国科学院大学岗位教师。2012年获密歇根州立大学博士学位，之后在德州大学奥斯汀分校、麻省大学阿姆斯特分校从事博士后研究，2017年12月回国后任副研究员，2021年2月起任研究员。目前主要的研究兴趣包括有效场论理论和应用、电弱散射振幅、中微子和Higgs物理、物质反物质不对称及暗物质宇宙学，在相关研究领域发表期刊文章80余篇。