Nonperturbative Yukawa theory at finite density and temperature

TL;DR

This paper explores the nonperturbative thermodynamics of in-medium Yukawa theory at finite temperature and density using optimized perturbation theory, highlighting its validity across various parameters and conditions.

Contribution

It applies the OPT framework to Yukawa theory, providing nonperturbative insights into its thermodynamics beyond weak coupling and including condensate effects.

Findings

Second order PT fails with condensates but performs well without them.

OPT provides valid results for arbitrary masses, temperature, and chemical potential.

Comparison with nonperturbative results validates the approach.

Abstract

In-medium Yukawa theory is part of the thermodynamics of the Standard Model of particle physics and is one of the main building blocks of most effective field theories of fermionic systems. By computing its pressure we investigate the nonperturbative thermodynamics at finite temperature and density using the optimized perturbation theory (OPT) framework. Our calculations are valid for arbitrary fermion and scalar masses, temperature, chemical potential, and not restricted to weak coupling. The model is considered in the presence as well as in the absence of condensates. Comparison with nonperturbative results shows that second order perturbation theory (PT) fails in the first case but performs rather well when condensates are absent, even at high-temperature regimes.