Special Seminar

Speaker: Ming-Lei Xiao (Institute of Theoretical Physics)
Title: Selection Rules and Operator Counting from Amplitude Basis
Date: Thu, Jan 23, 2020, 13:30 - 14:30
Place: Seminar Room A
Related File: 2502.pdf
Abstract: We study the amplitude basis as the building block of on-shell formalism, a new approach to scattering amplitudes in a generic theory including effective field theories, and find exciting phenomenological implications. The main focus of my talk will be a series of new selection rules under the principle of angular momentum conservation, which restrict the ways effective operators contribute in loop calculations. We define the partial wave amplitude basis and corresponding operator basis, for which the selection rules become apparent. We get new non-renormalization relations and exactly vanishing loops that are already found in literature but not well explained. We also introduce our on-going program of counting and *listing* all effective operators with the help of amplitude basis.