Description:

Title: The Infrared Structure of Scalar Effective Field Theories

Speaker: Zhewei Yin, Northwestern University 
 

Abstract:

One important aspect in the study of scalar effective field theories (EFTs) is the infrared structure of these theories. On the one hand, recently in the amplitude program, the study of soft theorems of scalar EFTs unveils surprising structures hidden in these theories. On the other hand, in many new physics models, the Higgs is a pseudo Nambu Goldstone boson (pNGB) associated with a broken symmetry at a high energy scale, which is beyond the reach of current experiments. Therefore, it is crucial to fully understand the connection between the infrared structure of scalar EFTs and the full theory at ultraviolet.

I present our recent works addressing both the purely theoretical and the phenomenological aspects of this topic. Using conventional field theory methods, we take a step further toward fully understanding the novel results of the amplitude program. Meanwhile, we utilize our knowledge of the universal infrared structure of nonlinear sigma model to study its implications for Higgs physics. Our results suggest that a universal test can be performed to determine whether Higgs is a pNGB or not, regardless of the details of the full theory at ultraviolet.

Keywords: Physics, Astronomy, HEP