Relaxation of a Goldstino-like mode due to supersymmetry breaking in Bose-Fermi mixtures

TL;DR

This paper investigates how explicit supersymmetry breaking in Bose-Fermi mixtures causes the Goldstino-like fermionic mode to relax, leading to spectral broadening, analyzed using the Kubo-Tomita theory.

Contribution

It applies the Kubo-Tomita theory to analyze spectral broadening of the Goldstino mode due to supersymmetry breaking in Bose-Fermi mixtures, drawing parallels with electron spin resonance.

Findings

Goldstino mode broadens when supersymmetry is broken.

Spectral lineshape broadening can be quantitatively described.

The analysis reveals similarities with magnetic resonance phenomena.

Abstract

In the presence of nonrelativistic supersymmetry, a sharp fermionic collective mode similar to the Goldstino mode in high-energy physics was proposed to be realized in Bose-Fermi mixtures. The Goldstino mode is relaxed (a.k.a. decays) if supersymmetry is explicitly broken, which can be revealed as the broadening of the corresponding spectral function. We find that the situation shares many similarities with the electron spin resonance in magnetic systems and adopt the well-known Kubo-Tomita theory to perform a general analysis of the spectral function lineshape broadening of the Goldstino mode.