Fresh look at the Hagedorn mass spectrum as seen in the experiments

TL;DR

This paper introduces a model incorporating medium-dependent widths into the Hagedorn mass spectrum, explaining the deficit of observed resonances and the invisibility of heavy QGP bags in experiments.

Contribution

It presents an exactly solvable model with finite width effects that aligns with lattice QCD data, providing new insights into the QGP bag spectrum.

Findings

Large widths explain the resonance deficit.

Heavy QGP bags are not directly observable.

Model matches lattice QCD data.

Abstract

The medium dependent finite width is introduced into an exactly solvable model with the general mass-volume spectrum of the QGP bags. The model allows us to estimate the minimal value of the QGP bags' width from the lattice QCD data. The large width of the QGP bags not only explains the observed deficit in the number of hadronic resonances comparing to the Hagedorn mass spectrum, but also clarifies the reason why the heavy QGP bags cannot be directly observed as metastable states in a hadronic phase.