Diquark Correlators and Phase Structure in the Quark-Meson-Diquark Model beyond Mean Field

TL;DR

This paper investigates the phase structure of the two-flavor quark-meson-diquark model using nonperturbative functional renormalization group methods, highlighting the impact of mesonic fluctuations beyond mean-field approximations.

Contribution

It provides a detailed analysis of diquark correlators and phase transitions beyond mean field, emphasizing the role of mesonic fluctuations and diquark condensation.

Findings

Mesonic fluctuations significantly alter the phase structure.

Diquark condensation dominates at strong diquark couplings.

The diquark pole mass and Silver-Blaze property are analyzed.

Abstract

A comprehensive study of the phase structure of the two-flavor quark-meson-diquark model is presented within the nonperturbative functional renormalization group framework. The influence of mesonic fluctuations beyond the mean-field approximation is investigated, and two-point functions of the diquark fields are computed at finite real-time frequencies. Renormalization group consistency of the effective potential is ensured in order to avoid cutoff artifacts. Substantial modifications of the phase structure are found once mesonic fluctuations are included, and for sufficiently strong diquark couplings the dynamics become dominated by diquark condensation. These effects are elucidated through an analysis of the diquark pole mass and the Silver-Blaze property.