# Baryonic susceptibilities, quark-diquark models, and quark-hadron duality at finite temperature

## TL;DR

This paper investigates baryonic charge fluctuations at finite temperature using a quark-diquark model, showing that these fluctuations can be explained by excited baryonic states with a confining interaction, aligning well with lattice QCD results.

## Contribution

It introduces a quark-diquark model to describe baryonic susceptibilities and demonstrates consistency with lattice QCD data and other models, advancing understanding of quark-hadron duality.

## Key findings

- Quark-diquark potential matches quark-antiquark potential in static limit.
- Baryonic fluctuations are well described by the quark-diquark model.
- Results agree with lattice QCD data for susceptibilities.

## Abstract

Fluctuations of conserved charges such as baryon number, electric charge and strangeness may provide a test for completeness of states in lattice QCD for three light flavors. We elaborate on the idea that the corresponding susceptibilities can be saturated with excited baryonic states with an underlying quark-diquark structure with a linearly confining interaction. Using Polyakov-loop correlators we show that in the static limit, the quark-diquark potential coincides with the quark-antiquark potential in marked agreement with recent lattice studies. We thus study in a quark-diquark model the baryonic fluctuations of electric charge, baryon number and strangeness: $\chi_{BQ}$, $\chi_{BB}$ and $\chi_{BS}$; by considering a realization of the hadron resonance gas model in the light flavor sector of QCD. These results have been obtained by using the baryon spectrum computed within a relativistic quark-diquark model, leading to an overall good agreement with the spectrum obtained with other quark models and with lattice data for the fluctuations.