Superfluid effective field theory

In this talk, I will present new developments in an effective field theory (EFT) of helium superfluid. One of the motivation to build this framework is to understand a test particle scattering of the superfluid with its de Broglie wavelength shorter than the average helium spacing. The scattered helium atom will produce a few to thousands of quasi-particles. Due to mixing with different momentum scales, a naive EFT of the superfluid breaks down, but a novel EFT is introduced to describe how helium atoms decay to quasi-particles and quasi-particles are thermalized.

Host:  Tarek Saab