Thermal shifts, fluctuations, and missing states

TL;DR

This paper investigates how thermal shifts and fluctuations at finite temperature can reveal missing hadronic states, comparing different models and lattice QCD data to understand hadronic completeness.

Contribution

It compares three hadron resonance gas models and discusses their implications for identifying missing states using lattice QCD results.

Findings

Hadronic completeness affects thermodynamic observables.

Different models yield varying predictions for missing states.

Lattice QCD data constrains the hadronic spectrum.

Abstract

Thermal shifts and fluctuations at finite temperature below the deconfinement crossover from hadronic matter to the quark-gluon plasma provide a viable way to search for missing states with given quantum numbers in the hadronic spectrum. We analyze three realizations of the hadron resonance gas model in the light quark (uds) sector: the states from the Particle Data Group tables with or without width and from the Relativized Quark Model. We elaborate on the meaning of hadronic completeness and thermodynamical equivalence on the light of lattice QCD trace anomaly, heavy quark entropy shift and baryon,charge and strangeness susceptibilities.