Application of Maximum Entropy Method to Dynamical Fermions

TL;DR

This paper applies the Maximum Entropy Method to analyze spectral functions in dynamical fermion simulations of the (2+1)-dimensional Nambu-Jona-Lasinio model, revealing detailed spectral features in different phases.

Contribution

It demonstrates the effectiveness of the Maximum Entropy Method in extracting spectral functions from lattice simulations of a complex fermionic model with phase transitions.

Findings

Spectral functions of elementary fermions and mesons were successfully extracted.

Distinct spectral features identified in broken and symmetric phases.

Resonance structures in the symmetric phase were characterized.

Abstract

The Maximum Entropy Method is applied to dynamical fermion simulations of the (2+1)-dimensional Nambu-Jona-Lasinio model. This model is particularly interesting because at T=0 it has a broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are resonances, and hence the simple pole assumption of traditional fitting procedures breaks down. We present results extracted from simulations on large lattices for the spectral functions of the elementary fermion, the pion, the sigma, the massive pseudoscalar meson and the symmetric phase resonances.