Speaker
Description
In this presentation, I will introduce part of our paper, which is a collaboration between my advisor Anna Tokareva, my academic siblings and friends Yong-jun and Long-Qi, and myself. I will begin with a brief overview of some fundamental concepts of effective field theory (EFT). Then, I will explain how, by applying dispersion relations, we can separate the infrared (IR) and ultraviolet (UV) contributions in EFT. This separation allows us to derive constraints on low-energy (IR) EFT coefficients based on the well-behaved properties of the high-energy (UV) sector.
Recently, a method known as the EFT-hedron was developed by Nima Arkani-Hamed, Yu-tin Huang, and their collaborators. Using this approach, the authors were able to analytically derive bounds on the ratios g_3/g_2 and g_4/g_2 at tree level, which remarkably match the results obtained through numerical methods (see arXiv:2011.02957). However, beyond tree level, the appearance of \log t terms leads to divergences in the forward limit (t \to 0), making it challenging to include loop-level contributions. After briefly reviewing these results, I will discuss how to address the divergence problem associated with loop-level amplitudes, then present our modified bounds and offer a discussion of this modification.
