Remarkable Features of Decaying Hagedorn States

TL;DR

This paper explores the properties and decay behaviors of Hagedorn states, revealing their thermal-like energy spectra and potential role in the hadronization process near the QGP-HRG phase transition.

Contribution

It introduces a covariant bootstrap model for Hagedorn states, analyzing their decay chains and resulting hadron spectra, highlighting their thermal characteristics near the critical temperature.

Findings

Hagedorn states decay into stable hadrons with thermal-like energy spectra.

Decay chain calculations produce hadron multiplicities and ratios consistent with thermal distributions.

Hagedorn temperature $T_H$ characterizes the energy spectra of decay products.

Abstract

Hagedorn states (HS) are a tool to model the hadronization process which occurs in the phase transition phase between the quark gluon plasma (QGP) and the hadron resonance gas (HRG). Their abundance is believed to appear near the Hagedorn temperature $T_H$ which in our understanding equals the critical temperature $T_c$. These hadron-like resonances are characterized by being very massive and by not being limited to quantum numbers of known hadrons. To generate a whole zoo of such new states we solve the covariantly formulated bootstrap equation by regarding energy conservation and conservation of the baryon number $B$, strangeness $S$ and electric charge $Q$. To investigate their decay properties decay chain calculations of HS were conducted. One single (heavy) HS with certain quantum numbers decays by various two-body decay channels subsequently into final stable hadrons. Multiplicities of these stable hadrons, their ratios and their energy distributions are presented. Strikingly the final energy spectra of resulting hadrons show a thermal-like distribution with the characteristic Hagedorn temperature $T_H$. All hadronic properties like masses, spectral functions etc. are taken from the hadronic transport model Ultra Relativistic Quantum Molecular Dynamics (UrQMD).