What can we learn from few-body systems using EFTs?
Speaker: Xincheng Lin
Affiliation: NC State University
Date: November 13th
Abstract: Few-body systems, such as triton treated as a three-nucleon system, are great testing ground for nuclear theories because they are relatively simple and in some theories can be solved exactly. These systems are the starting point for understanding strong interactions using nuclear effective field theories (EFTs) at low energies where QCD is non-perturbative. I will talk about three- and four-body systems in EFTs with contact interactions, with a focus on how approximate symmetries and renormalization group can affect interactions that appear at different orders of the EFT expansion. In particular, I will discuss these topics in the context of low-energy neutron capture on a deuteron into a triton plus a photon, a threenucleon process that is also potentially relevant for studying parity violation in few-nucleon systems. For four-body systems, I will focus on four-boson binding energies in the unitary limit, where the two-body scattering length becomes infinite, and its connection to nuclear systems.